Corresponding author: Timothy D. Stebbins (
Academic editor: Saskia Brix
The isopod crustaceans reported from or expected to occur in littoral and sublittoral marine habitats of the Southern California Bight (
Stebbins TD, Wetzer R (2023) Review and guide to the isopods (Crustacea, Isopoda) of littoral and sublittoral marine habitats in the Southern California Bight. ZooKeys 1162: 1–167.
The Southern California Bight (
Southern California Bight region from Point Conception, California, USA to Punta Colonet, Baja California, Mexico, including the eight Channel Islands and Islas Coronado.
There are a number of general monographs, natural history guides, taxonomic keys, and other works relevant to the coastal marine invertebrates of the northeastern Pacific Ocean that contain useful information on
The purpose of this guide is to review all macrobenthic species of isopods known or expected to occur in littoral or sublittoral marine habitats of the
A key to the suborders and superfamilies of marine isopods occurring in the
Examples of representative family-level body types for each of the six suborders of marine isopods occurring in the
All species currently recognized by the Southern California Association of Marine Invertebrate Taxonomists (
The higher-level classification of crustaceans and isopods has evolved over the past two decades, with 11 isopod suborders currently recognized, of which eight include marine species (e.g., see
The
Body usually dorsoventrally depressed but may be cylindrical or tubular in some suborders (e.g., Anthuridea and Phreatoicidea).
Body without a carapace but with a cephalic shield.
Head (cephalon) compact, typically with compound eyes, two pairs of antennae (first pair minute in Oniscidea), and mouthparts comprising one pair of mandibles, two pairs of maxillae, and one pair of maxillipeds.
Compound eyes sessile (not stalked) but may be on ocular lobes in some Asellota, Cymothoida (i.e., Gnathiidae), and Valvifera.
First and second antennae (antennules and antennae, respectively) uniramous, but with minute scales in a few taxa.
Mandible usually with a 1- to 3-articulate palp and a multidentate incisor process, left and right lacinia mobilis often differ, molar process highly variable.
First and second maxillae (maxillules and maxillae, respectively) without palps.
First thoracic appendages (thoracopods) modified as maxillipeds comprising fifth pair of mouthparts.
Long thorax of eight segments (thoracomeres), the first (and second in Gnathiidae) fused to the cephalon and bearing the maxillipeds, the remaining seven segments (pereonites) being free and collectively comprising a region called the pereon.
Pereon with seven pairs of uniramous legs (pereopods), all generally alike; the exception being the Gnathiidae in which only five pairs of walking legs are present.
Abdomen (pleon) relatively short comprising six somites (pleonites), at least one of which is always fused to the telson to form a pleotelson.
Six pairs of biramous pleonal appendages, including five pairs of plate-like pleopods specialized for respiration and/or swimming, and one pair of fan-like or stick-like, uniarticulate uropods.
Heart located primarily in the pleon.
Young isopods develop within a brood pouch (female’s marsupium) and emerge as a manca before appearance of the last pair of pereopods. Mancas have six pairs of pereopods.
Biphasic molting in which the posterior half of the body molts before the anterior half.
In terms of reproductive status, isopods can be sexed based on the presence or absence of male or female secondary sex characters. If oostegites (or a marsupium) are present with or without eggs or developing embryos, an individual is obviously female. If oostegites are absent, males can be distinguished by the presence of paired penes (may be fused) on the sternum of pereonite 7 (or pleonite 1) and/or appendices masculinae on the endopods of the second pleopods. Absence of all these characters indicates that the individual is either a juvenile, an immature female, or an immature male that has not yet developed secondary sexual features.
Terminology in the keys follows that which is typical for isopods in general (see
Bopyrid isopod body plan (adult female).
In general, the isopod body is divided into three regions: the cephalon (head), pereon, and pleon. The cephalic region is referred to as “head” throughout the following keys. The segments of the pereon are referred to as pereonites 1–7 for most taxa or as pereomeres 1–7 for the epicarideans. Likewise, the segments of the pleon are referred to as pleonites 1–5 and the pleotelson (incorporating the fused pleonite 6 and telson) for most taxa (unless fused into fewer segments) or as pleomeres 1–6 plus telson for the epicarideans. The appendages of the pereon are numbered as pereopods 1–7, while the appendages of the pleon are referred to as pleopods 1–5 plus the uropods for all taxa. The first antennae (antenna 1) and second antennae (antenna 2) are referred to as antennules and antennae, respectively. Additional terminology is defined in glossaries of technical terms provided in
A total of 190 species of isopods are covered in this review of the Southern California Bight (
Of the six isopod suborders occurring in
Number of families, genera, and species for each of the six isopod suborders occurring in littoral and sublittoral marine habitats of the Southern California Bight. For suborders represented by more than one superfamily, the breakdown per superfamily is indicated.
Suborder/Superfamily | Number taxa per group | ||
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Families | Genera | Species | |
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Superfamily |
5 | 10 | 11 |
Superfamily |
6 | 18 | 38 |
Infraorder |
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Superfamily |
2 | 16 | 17 |
Superfamily |
2 | 3 | 3 |
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Superfamily |
1 | 1 | 1 |
Superfamily |
3 | 12 | 24 |
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Superfamily |
11 | 25 | 54 |
Superfamily |
1 | 1 | 1 |
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The suborder
The superfamily
The sixth family of
The suborder
The suborder
The suborder
The suborder
The suborder
Ten keys were constructed to facilitate identification of the 190 species of isopods included in this guide. Key A represents a key to the suborders and main superfamilies, which are then identified to species in Keys B–J. Keys B–E cover the suborder
1 | Adult isopods free-living, but may live commensally with other isopods or invertebrates; females and males with clear bilateral symmetry, typically similar in size; antennae well developed, never vestigial; antennules variable |
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– | Adult isopods obligate parasites of other crustaceans; females with slightly to highly distorted or reduced bilateral symmetry; male minute, bilaterally symmetrical, living on body of adult female; antennae vestigial in female; antennules reduced to ≤ 3 articles [Suborder |
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2 | Adult isopods with 5 pairs of pereopods (thoracomere 2 fused to cephalon with its appendages modified into pylopods; thoracomere 8 reduced, without legs); adult males with enlarged, forward projecting forceps-like mandibles; females without mandibles [Suborder |
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– | Adult isopods usually with 7 pairs of distinct pereopods (7th pair may be small and folded against ventral body wall in juveniles); newly released isopods (mancas) from the marsupium with only 6 pairs of pereopods; males without projecting forceps-like mandibles; females with mandibles |
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3 | Species terrestrial or halophilic, mostly restricted to upper littoral (e.g., high tide line, spray zone) or brackish water habitats along coast; antennules vestigial, minute; pleon always composed of 5 free pleonites plus pleotelson [Suborder |
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– | Species fully marine, occurring in littoral or sublittoral habitats; antennules normal, or not minute if reduced; pleon variable, with or without fused pleonites |
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4 | Uropods operculate, modified into pair of ventral covers (opercula) enclosing the pleopods (Fig. |
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– | Uropods not modified as ventral opercula, hinged laterally or terminally on pleotelson |
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5 | Uropods typically flattened and hinged on anterolateral margins of pleotelson (may be greatly reduced) |
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– | Uropods styliform and hinged terminally or nearly so on posterior margins of pleotelson [Suborder |
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6 | Adult body elongated, usually > 6 × longer than wide [Suborder |
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– | Adult body not elongated, < 4 × longer than wide (not elongated) |
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7 | Uropods greatly reduced with small claw-like exopods, generally not visible dorsally; species burrow in wood or algal holdfasts [Suborder |
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– | Uropods not as above, clearly visible dorsally as expanded, flattened “tail fan” or long caudal processes |
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8 | Pleon composed of 4 or 5 free pleonites plus pleotelson [Suborder |
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– | Pleon composed of ≤ 3 free pleonites plus pleotelson [Suborder |
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Figs
1 | Eyes present |
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– | Eyes absent |
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2 | Mouthparts form forward directed cone-like structure under the head, adapted for piercing and sucking | |
– | Mouthparts not forming ventral cone-like structure, adapted for biting and chewing |
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3 | Pereon composed of 7 distinct, well-developed pereonites with 7 pairs of pereopods; pereonite 7 ca. half as long as pereonite 6 and visible laterally |
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– | Pereon composed of 6 distinct pereonites with 6 pairs of pereopods (7th pereopods absent); pereonite 7 very short, < 20% as long as pereonite 6, not visible laterally |
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4 | Pleonites 1–5 free, not fused; pleonite 5 ca. 3 × longer than other pleonites (Fig. |
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– | Pleonites 1–5 fused mid-dorsally, but distinct laterally; all pleonites of similar length (Fig. |
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5 | Pleonites 1–5 free, separated from each other by dorsal integumental folds; pleonite 1 ca. 2 × longer than pleonite 2 (Fig. |
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– | Pleonites 1–5 dorsally fused, all pleonites of similar length (Fig. |
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6 | Dorsal surface of pleotelson with median row of spines; uropodal and pleotelsonic margins serratedEndnote 2 | |
– | Dorsal surface of pleotelson smooth or ridged, without spines; uropodal and pleotelsonic margins not serrated | |
7 | Pleotelson with 3 raised dorsal longitudinal ridges or carinae; uropodal exopods curve up and over base of pleotelson (Fig. |
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– | Pleotelson without dorsal ridges or carinae; uropodal exopods may or may not curve up over pleotelson |
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8 | Pleonites 1–5 fused only along dorsal midline, segments free laterally and visible dorsally; uropodal exopods ca. half length of endopods and pleotelson, curving up and partially over pleotelson base; uropodal endopods narrow, ca. half as wide as pleotelson (Fig. |
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– | Pleonites 1–5 completely fused dorsally; uropodal exopods > 50% length of endopods and pleotelson, may or may not cover the pleotelson dorsally; uropodal endopods broad, subequal in width to pleotelson |
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9 | Dorsal surface of pereon pigmented, with complete or nearly complete dark rings on pereonites 2–6 and posterior transverse band on pereonite 7; uropodal exopods partially cover dorsal surface of pleotelson (Fig. |
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– | Dorsal surface of pereon covered with diffuse pigment splotches, but without pigment rings; uropodal exopods do not cover base of pleotelson (Fig. |
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10 | Uropodal exopods with distinct lateral lobes, exopods overlapping broadly to cover almost entire dorsal surface of pleotelson; uropodal rami nearly reach, but do not exceed, posterior margin of pleotelson; tips of uropodal rami without tufts of stiff setae (Fig. |
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– | Uropodal exopods without lateral lobes, overlapping only base of pleotelson; uropodal endopod distinctly longer than pleotelson; tips of uropodal rami with tufts of long stiff setae (Fig. |
Figs
1 | Pereopods 1–3 ambulatory with dactylus shorter than propodus (e.g., Fig. |
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– | Pereopods 1–3 prehensile or sub-prehensile with dactylus generally as long as, or longer than propodus and strongly curved (e.g., Fig. |
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2 | Eyes absent; head immersed in pereonite 1 with posterior margin appearing deeply concave; pereon with coxae 4–7 produced beyond posterior margins of their respective pereonites, at least 2 or more visible in dorsal view; lateral margins of pleonite 5 obscured by pleonite 4 (Fig. |
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– | Eyes present; posterior margin of head not appearing distinctly concave; with or without dorsally visible coxae on pereonites; lateral margins of pleonite 5 may or may not be obscured by pleonite 4 |
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3 | Coxae of pereonites 2–7 well-developed, typically visible in dorsal view and expanded laterally with acute posterior angles; epimeres of pleonites 2–5 well-developed, expanded laterally, with acute posterior angles; pleotelson with squarish to pointed posterior margin and a strong, middorsal longitudinal ridge; margins of pleotelson and uropodal rami notched (Fig. |
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– | Pereonites, pleonites, pleotelson and uropods not as above |
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4 | Head with prominent spatulate rostral process separating left and right antennules (Fig. |
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– | Head without a prominent rostral process between antennules |
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5 | Posterior margin of pleotelson broadly rounded and crenulate; antennular peduncle articles 2 and 3 subequal in length (Fig. |
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– | Posterior margin of pleotelson obtusely rounded and acuminate; antennular peduncle article 3 longer than article 2 (Fig. |
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6 | Antennules geniculated, with peduncle article 1 longer than articles 2 or 3, and article 2 arising at right angles to article 1; peduncle of antennae with 4 articles, antennae long and extending beyond pereonite 7; lateral margins of pleonite 5 not obscured by pleonite 4; uropodal rami truncate distally, exopod does not extend to posterior margin of pleotelson (Fig. |
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– | Antennules not geniculated; peduncle of antennae with 5 articles; lateral margins of pleonite 5 obscured by pleonite 4; uropodal rami distally rounded or acuminate, extending beyond posterior of pleotelson |
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7 | Uropodal rami with apical notches and not distally rounded; peduncle articles 1 and 2 of antennules fused; coxae of pereonites 5–7 visible dorsally; pereonites, pleonites and pleotelson without dorsal tubercles, carina, or setae (Fig. |
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– | Uropodal rami rounded distally, without notches; peduncle articles 1 and 2 of antennules not fused; coxae visible dorsally on pereonites 2–7; pleonites 3–5 with row of small tubercles on posterior margins; pleotelson of adult males with two large dorsal submedian tubercles or carinae (Fig. |
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8 | Pereopods 4–7 ambulatory (dactylus shorter than propodus) |
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– | Pereopods 4–7 prehensile (dactylus generally as long as, or longer than propodus and strongly curved); adults parasitic on fishes | |
9 | Dorsal surface of pleon tuberculate, with small to medium tubercles present on posterior margins of at least pleonites 3–5 |
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– | Dorsal surface of pleon without tubercles | |
10 | Pleotelson dorsally setose, lateral margins with single incision | |
– | Pleotelson not dorsally setose, lateral margins without incisions | |
11 | Male head with 3 large horns or tubercles, including 1 rostral and 2 posterolateral between the eyes (female without tubercles); pereonites 2–7 without dorsal setae or tubercles; pleotelson subtriangular with rounded apex, dorsal surface setose except for median longitudinal area (Fig. |
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– | Head of both males and females without horns or tubercles; pereonites 4–7 with dorsal setae and row of small tubercles on posterior margin; pleotelson triangular with subacute apex, entire dorsal surface densely covered with bifid golden setae (Fig. |
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12 | Body dorsal surface sculptured with low or small tubercles; head of male with 5 low tubercles, including 1 rostral, 1 pair near anterior margin, and 1 pair near posterior margin; male pereonite 1 with 2 small, median tubercles near anterior margin; female lacking tubercles on head and pereon; pleonites 3–5 with small tubercles on posterior margins; pleotelson minutely tuberculate dorsally with widely rounded, slightly crenulate posterior margin (Fig. |
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– | Body dorsal surface sculptured with large processes and numerous tubercles; male head with 2 dorsal posterolateral horns, frontal margin produced into large, upturned process and smaller ventrally projecting rostrum; pereonite 1 with 3 large dorsal processes; all pereonites and pleonites with numerous dorsal tubercles that increase in size and become more spine-like posteriorly; pleotelson triangular with subtruncate apex, dorsally covered with longitudinal rows of large, spine-like tubercles; females much less spinose than males, lacking large processes on head and pereonite 1 (Fig. |
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13 | Peduncular articles 1 and 2 of antennules greatly expanded (dilated), article 2 with gradual distal process extending 25–50% the distance into article 3; posterior margin of pleotelson truncate, crenulated and fringed with setae (Fig. |
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– | Peduncular articles of antennules not dilated, article 2 without distal process; posterior margin of pleotelson rounded or subacuminate |
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14 | Eyes large, close-set, nearly touching at midline; pleotelson shield-shaped with subacuminate apex and weekly serrated (notched) posterolateral margins; uropodal rami ovate with subacuminate apices (Fig. |
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– | Eyes medium to large, but distinctly separated and not nearly touching medially; posterior margin of pleotelson rounded; uropodal rami with broadly rounded to truncate apices |
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15 | Medial process of uropodal peduncle very long, extending at least 75% of length of endopod |
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– | Medial process of uropodal peduncle extends 50% or less of length of endopod |
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16 | Propodi of pereopods 1–3 with large, broad, spine-bearing medial lobe; dactyli of pereopods 1–3 longer than propodi; frontal lamina broadly expanded anteriorly, arrowhead or spatulate shaped (Fig. |
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– | Propodi of pereopods 1–3 without expanded medial lobe; dactyli of pereopods 1–3 subequal in length to propodi; frontal lamina thin and narrow (Fig. |
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17 | Medial process of uropodal peduncle extends < 40% of length of endopod; propodi of pereopods 1–3 with 4 stout, recurved acute spines; merus of pereopods 1–3 with 5–8 acute spines (3–5 distal, 2 or 3 proximal) (Fig. |
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– | Medial process of uropodal peduncle extends ~ 50% of length of endopod; propodi of pereopods 1–3 with 4–6 acute spines; merus of pereopods 1–3 with 4 acute spines (3 distal, 1 proximal) |
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18 | Propodi of pereopods 1–3 with 5 thin, straight acute spines; apical article of maxillipedal palp with thin, nearly straight, acute spines (Fig. |
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– | Propodi of pereopods 1–3 with 4–6 stout and recurved acute spines; apical article of maxillipedal palp with stout, recurved acute spines (Fig. |
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19 | Pleopods and uropods not setose |
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– | Pleopods and uropods heavily setose, adapted for swimming (juvenile cymothoids)Endnote 4 |
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20 | Body very broad and darkly pigmented; pereon at least 2× as wide as pleon with strongly convex lateral margins (widest at pereonite 5); parasite of barspot cardinalfish and Panamic fanged blenny in Eastern Pacific (Fig. |
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– | Body not as above |
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21 | Posterior margin of head weakly to strongly trisinuate; pleon not immersed in pereon |
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– | Posterior margin of head not trisinuate; pleon partially immersed in pereon |
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22 | Head not immersed in pereonite 1, posterior border distinctly trisinuate; coxal margins of all or just posterior pereonites with acute or subacute posterolateral angles, coxae may be held close to body ( |
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– | Head somewhat immersed in pereonite 1, subquadrate anteriorly with weakly trisinuate posterior border; uropods not visible in dorsal view, typically held concealed under pleotelson and not extending beyond posterior border; parasite of Pacific bumper, pompanos, serranos, carangids, and other fishes (Fig. |
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23 | Basal articles of antennules expanded and touching or nearly touching |
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– | Basal articles of antennules not expanded and touching |
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24 | Pereopods 4–7 carinate; posterior margin of pleonite 5 trisinuate except in occasional males; parasite of pelagic fishes, including striped mullet off southern California and pompanos and herring off Baja California (Fig. |
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– | Pereopods 4–7 not carinate; posterior margin of pleonite 5 smooth, not trisinuate; parasite of mullets and flatfish (Fig. |
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25 | Antennules longer than antennae; parasite of California and skipper halfbeaks (Fig. |
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– | Antennules shorter than antennae |
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26 | Frontal margin of head broadly rounded or truncate (not produced); bases of pereopods 4–7 with distinct carinae; coxae of pereonites 6 and 7 extending to and usually beyond posterior edge of respective pereonites; pleotelson in adult females nearly 2× as wide as long; parasite of at least 30 species of fishes (Fig. |
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– | Frontal margin of head produced; bases of posterior pereopods of females without distinct carinae; coxae of pereonites 6 and 7 not reaching posterior margins of respective pereonites; pleotelson in adult females either as wide as or wider than long |
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27 | Merus and carpus of pereopod 4 expanded; bases of pleopods with well-developed accessory lamellae; pleotelson in adult females broadly rounded, ~ 1.5–2.0 × wider than long; males with coxal carinae on pereopods 4–7; parasite of wooly sculpin, northern clingfish, and reef finspot (Fig. |
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– | Merus and carpus of pereopod 4 not expanded; accessory lamellae of pleopodal bases not well developed; pleotelson in adult females ca. as wide as long; males without carinae on posterior pereopods; parasite of surfperch, smelt, gobies, killifish, and grunion (Fig. |
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Fig.
1 | Head with enlarged forceps-like mandibles projecting anteriorly (male gnathiids) |
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– | Head not as above, without projecting mandibles; body often sac-like (female and juvenile gnathiids)Endnote 7 |
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2 | Eyes present, with or without pigment; telson variable in shape |
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– | Eyes absent; frontal margin of head (frons) with 3 central processes, laterals larger than middle process; epimeres single, dorsal, laterally projected; telson distinctly triangular (Fig. |
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3 | Pleotelson distinctly triangular |
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– | Pleotelson arrowhead or T-shaped with base expanded |
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4 | Pleonal epimeres laterally expanded, highly visible; body with few to numerous setae |
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– | Pleonal epimeres not laterally expanded, barely visible; body with relatively few setae |
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5 | Frontal margin of head forming broad, transverse, minutely crenulated plate (best viewed ventrally); eyes brown to reddish brown; body setosity light, without numerous setae; pleopods without setae (Fig. |
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– | Frontal margin of head not transverse (lobes or processes present); eyes reddish brown; body not hirsute, but with numerous setae; pleopods with setae |
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6 | Body mottled with brown pigment; frontal margin of head forming centrally extended narrow lobe with crenulations; mandibles split into 2 articlesEndnote 8 |
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– | Body without pigment; frontal margin of head trilobed with 3 central subequal processes; mandibles of single article only (not split into 2 articles) (Fig. |
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7 | Eyes dark brown, body mottled with brown pigment; frontal margin of head with 3 processes, median process largest and shaped as stepwise pyramid; head with setae and tuberculations (Fig. |
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– | Eyes reddish brown; body without pigmentation; frontal margin of head with central 3-dimensional expansion in shape of box, with 2 large setae extending outward centrally; head with setae, but lacking tuberculationsEndnote 8 |
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8 | Pleotelson distinctly T-shaped |
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– | Pleotelson arrowhead-shaped |
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9 | Eyes sessile, dark brown, lens with tuberculations; body speckled with tiny black dots; frontal margin of head produced into single large lobe; pleopods ovate, paddle-like; body hirsute (Fig. |
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– | Eyes on distinct ocular peduncles, unpigmented, lens without tuberculations; frontal margin of head with 2 medium–large lateral processes and 4 central subequal processes; pleopods long and narrow; body hirsute (Fig. |
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10 | Pleonal epimeres double (dorsal and ventral); eyes golden/amber in color; frontal margin of head with 3 central, subequal processes; body with numerous scattered setae, but not hirsute (Fig. |
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– | Pleonal epimeres single (dorsal only) |
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11 | Eyes golden or amber in color; head with dorsal carina present; frontal margin of head as 1 broad truncate lobe with medial carina; body hirsuteEndnote 8 |
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– | Eyes with red and white checkerboard pattern; head without dorsal carina; frontal margin of head with 3 central subequal processes; body not hirsute, but with numerous setae (Fig. |
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Figs
1 | Body of adult female distinctly segmented with clear division of head (cephalon), thoracic (pereon), and abdominal (pleon) regions | |
– | Body of adult female sac-like, with at most weak segmentation visible | |
2 | Adult female body broadly oval; pleon strongly torsioned and reflexed forward over pereon; head without eyes, deeply embedded in pereon, anterior margin covered by oostegites; pleomeres 3–6 fused medially; branchial parasite of deep-water crangonid shrimps of genus |
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– | Female body not as above, pleon not strongly reflexed over pereon |
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3 | Female pleon with pleopods and/or elongated lateral plates (epimeres or pleural lamellae) clearly noticeable in dorsal view |
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– | Female pleon without pleopods or elongated lateral plates noticeable in dorsal view |
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4 | Lateral plates of pleon and/or pleopods conspicuously elongate, foliaceous, or lanceolate, with or without digitated or crenulated margins |
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– | Lateral plates of pleon and pleopods relatively short, distal margins of pleopods mostly rounded |
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5 | Adult female with elongated lateral plates fringed with long, branched processes; branchial parasite of ghost shrimps of genus |
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– | Adult female with or without lateral plates, but lateral plates not as above if present |
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6 | Adult female body nearly oval, with oostegites conspicuously visible dorsally arching over margins of head and pereon; head longer than wide, deeply immersed in pereon, eyes absent; pereomere 6 much longer than other pereomeres, pereomeres 1–5 concave anteriorly, pereomeres 6 and 7 concave posteriorly; pleon with “triramous appendages” in appearance, but each one consists of a foliaceous lanceolate lateral plate and identical biramous pleopod; branchial parasite of hermit crabs |
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– | Adult female body not as above, pereomere 6 subequal in length to other pereomeres; pleon with lateral plates and pleopods not appearing like triramous appendages |
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7 | Adult females with pair of dorsolateral papillae on pleomere 1; pleon with long, narrow biramous pleopods arising from thin peduncle or stem on each segment, without lateral plates; head slightly wider than long, bilobate, eyes absent; abdominal parasite of mud shrimps of genus |
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– | Adult females without dorsolateral papillae on pleomere 1; pleomeres with both elongated lateral plates and pleopods, but morphology of pleopods not as above |
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8 | Pleon of adult females enclosed by tentacular-like, elongated lanceolate lateral plates and pleopodal exopods, each with deeply digitate margins, ventral surface covered partially by smaller foliate pleopodal endopods with crenulated margins; head completely embedded in pereon, dorsal surface divided into two large sub-oval lobes, eyes absent; branchial parasite of grapsid crab |
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– | Pleon of adult females with lateral plates and pleopods not as above; head not bilobate |
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9 | Adult female body ~ 2 × longer than wide, pyriform in shape; head slightly wider than long, eyes absent; coxal plates very large, overlapping, and extending well beyond lateral margins of pereomeres; pleon obscured by prominent ovate lateral plates and long, biramous lanceolate pleopods; branchial parasite of pelagic galatheid “red crab” |
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– | Adult female body slightly longer than wide; head subcircular, eyes absent; coxal plates prominent but not widely extended on pereomeres 1–4; lateral edges on convex side of pereomeres 5–7 produced into slender points reflexed back over dorsum; pleomeres 1–5 with dentate-margined lanceolate lateral plates and similar biramous pleopods; branchial parasite of hermit crab |
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10 | Adult female head somewhat bilobate, eyes absent; pereomeres 1–6 with sharply pointed tergal projections on longer side of body; pleomeres 1–5 with short lateral plates and distally rounded uniramous pleopods; branchial parasite of several genera of crangonid and hippolytid shrimps (e.g., |
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– | Adult females not as above; head not bilobate, with or without eyes; pereon without sharp tergal projections; pleopods biramous |
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11 | Adult female head wider than long with rounded anterior and posterior margins, eyes absent; narrow and rudimentary coxal plates on pereomeres 3 and 4 on both sides of body; branchial parasite of porcelain crab |
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– | Adult female head subtriangular in shape, anterolateral margins produced into small obtuse projections, eyes present; rudimentary coxal plates of pereomeres 3 and 4 only on longer side of body; branchial parasite of porcelain crabs |
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12 | Adult female body oval to broadly oval, pereon and pleon subequal in width; branchial parasite of mud shrimps of genus |
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– | Adult female body not oval, pleon tapering to much narrower than widest pereomeres |
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13 | Adult female body broadly oval, almost as wide as long (L:W ratio ~ 1.2); head almost square, deeply embedded in pereomere 1, eyes absent; ventral surface of pleomeres covered by overlapping lanceolate lateral plates and uniramous uropods, middle region covered by similar sized biramous pleopods (Fig. |
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– | Adult female body oval, distinctly longer than wide (L:W ratio ~ 1.5); head slightly wider anteriorly than posteriorly, deeply embedded in pereomere 1, eyes present; ventral surface of pleomeres covered by numerous ridges and lanceolate biramous, marginally tuberculate pleopods (Fig. |
|
14 | Pleon of adult females composed of 5 medially fused pleomeres and pleotelson, the latter deeply arcuate and embedded in pleomere 5; head roughly triangular, separated from pereon by deep groove, eyes absent; branchial parasite of hippolytid shrimps |
|
– | Adult female body not as above; pleomeres distinctly separate, not medially fused; head with or without eyes |
|
15 | Head of adult female partially fused with pereomere 1 and separated by only short lateral notches; frontal margin of head slightly sinuated with anterolateral process usually on just short side of body, small eyes present; pleotelson entirely set within curves of pleomere 5; branchial parasite of snapping shrimps |
|
– | Female head distinctly separate and not fused with pereomere 1, eyes absent; pleotelson not completely set within curves of pleomere 5 |
|
16 | Head of adult female squarish with distinct anterolateral horns and a small anteromedial indentation; pleon with 6 distinct pleomeres separated by deep lateral notches; pleopods 1–4 biramous (5th pair absent), uropods absent; branchial parasite of alpheid shrimp |
|
– | Female head wider anteriorly than posteriorly, without anterolateral horns; pleon with 5 pleomeres not separated by deep notches and very small 6th segment, 5 pairs of biramous pleopods, and terminal pair of lanceolate uropods |
|
17 | Endopods of pleopods 1–5 much larger than exopods, elongate and pointed, surface rough with irregular rugae; coxal plates of pereomeres 5–7 not developed as lamellae; branchial parasite of hermit crabs of genus |
|
– | Endopods of pleopods 1–5 only slightly larger than exopods, triangular or ovate, surface smooth; coxal plates of pereomeres 5–7 developed as lamellae; branchial parasite of squat lobsters |
|
18 | Adult female body simply an egg sac, without evidence of segmentation; antennae and mouthparts absent; parasite on barnacles of genera |
|
– | Adult female body with weak evidence of segmentation visible dorsally or laterally; antennae and mouthparts present; parasitic on caridean shrimp of families |
|
19 | Adult female body typically elongate and symmetrical, but may be irregular with deeper, stouter body in some specimens; head separate, typically hemispherical, visible dorsally or ventrally; segmentation of pereon usually visible laterally by 4 coxal plates; pleonal region posteriorly projected as unsegmented conical prominence; parasite on carapace of pasiphaeid shrimp |
|
– | Adult female body ovate, all regions fused and indistinct dorsally; posterior margin of pleon appears notched with row of triangularly shaped processes; parasite on carapace of pandalid shrimps |
|
Fig.
1 | Dorsal surface of pleotelson without symmetrically arranged tubercles; left mandible without rasp or file-like ridges; burrowing in algal holdfasts (Fig. |
|
– | Dorsal surface of pleotelson with 3 or 4 symmetrically arranged anterior tubercles; left mandible with rasp or file-like ridges (see Fig. |
|
2 | Dorsal surface of pleotelson with 3 anterior tubercles arranged in triangle; lateral and posterior margins of pleotelson tuberculate (Fig. |
|
– | Dorsal surface of pleotelson with 2 pairs of anterior tubercles; margins of pleotelson not tuberculate (Fig. |
|
Figs
1 | Pleon composed of 3 free pleonites plus pleotelson; body broad, depressed and platter-like; dorsum with distinct medial carinae (Fig. |
|
– | Pleon composed of 1 or 2 dorsally visible free pleonites plus pleotelson |
|
2 | Pereopod 1 subchelate in both sexes, with broadly expanded propodus and prehensile dactylus (propodus at least 5 × wider than dactylus); pereopod 2 prehensile only in males |
|
– | Pereopod 1 ambulatory or only weakly prehensile, propodus narrow (propodus < 2 × as wide as dactylus) | |
3 | Head medially fused to pereonite 1; pleopod 5 with both rami lacking transverse pleats or folds; uropods uniramous, lacking exopods | |
– | Head and pereonite 1 not fused; both rami of pleopod 5 with transverse pleats or folds; uropods biramous, exopods slender and spine-like; first segment of pleon with 3 suture lines (fused pleonites 1–4) and 2 small triangular processes on posterior margin; pleotelson with rounded posterior border (Fig. |
|
4 | Lateral margins of head strongly produced; pleon with 2 short posterior projections overhanging anterior margin of pleotelson; pleopod 1 biramous; uropodal ramus narrow proximally, then expands at least twofold for ~ 80% of length before tapering to acute point (Fig. |
|
– | Lateral margins of head weakly produced; pleon without posterior projections; pleopod 1 uniramous; uropodal ramus styliform, widest proximally and tapering to an acute point |
|
5 | Body broad (L:W ratio ~ 1.7) with densely granulated surfaces; pereonite 1 narrower than pereonites 2–7; pleotelson inflated, distinctly wider than long with truncate apex; eyes slightly elevated on swellings; uropods strongly recurved distally (Fig. |
|
– | Body relatively narrow (L:W ratio > 2.0) with smooth surfaces; pereonite 1 wider than pereonites 2–7; pleotelson not inflated, longer than wide with nearly acute or narrowly rounded apex; eyes not elevated; distal tips of uropods only slightly recurved (Fig. |
|
6 | Endopods of pleopods 4 and 5 without branchial pleats or folds |
|
– | Endopods of pleopods 4 and 5 with branchial pleats or folds |
|
7 | In lateral view, anterior margins of coxal plates of pereonites 2–4 appear raised and posterior margins not raised, giving the coxae a somewhat S-shaped appearance; species is fully marine (Fig. |
|
– | In lateral view, anterior margins of coxal plates 2–4 are not raised, and coxae do not appear S-shaped; species occurs in brackish or freshwater habitats (Fig. |
|
8 | Pleopods 4 and 5 with branchial pleats on both rami |
|
– | Pleopods 4 and 5 with branchial pleats only on endopods |
|
9 | Uropods of male highly modified, each composed of elongated, cylindrical, or flattened exopod and very short endopod fused to the protopod; both uropodal rami lamellar in females; ovigerous females with 4 pairs of oostegites on pereonites 1–4 |
|
– | Uropods lamellar in both sexes; ovigerous females with 3 pairs, 1 pair, or no pairs of oostegites |
|
10 | Pleotelson of males with pronounced posteromedial tooth that completely fills apical notch and extends posteriorly beyond level of notch opening; dorsum of pleotelson with 3 transverse elevations at base, median elevation terminating in a spine; body surface densely granulated; sexual dimorphism pronounced with female body smooth, lacking ornamentation or setae (Fig. |
|
– | Pleotelson of males with highly complex and open apical notch, internal lateral margins of notch with various numbers of teeth forming sinuses of different shapes; body surface not densely granulated; sexual dimorphism pronounced, females without complex pleotelsonic notch, terminal notch either very short and simple or absent; dorsum of pleotelson sculptured with various types of tubercles |
|
11 | Uropods of male with ventrolateral spines on exopods; female pleotelson stout, with 4 dorsal tubercles and wide, but shallow apical notch (Fig. |
|
– | Uropods of male without spines; female pleotelson not as above |
|
12 | Pleotelson of males long, subequal in length to pereon, with complex medial sinus formed by 2 pairs of teeth, pleotelsonic sinus expanded basally into round foramen overhung by basal knob bearing tall acute spine (spine length ≥ 4 × diameter), sinus then narrowing distally to long thin channel; female pleotelson with small distal notch and 5 dorsal tubercles (1 large medial, 4 smaller lateral); female uropodal exopods with sharply toothed posteromedial margins (Fig. |
|
– | Pleotelson of males relatively short, ca. half length of pereon; pleotelsonic sinus not as above, without round basal foramen, with or without short spine overhanging base of notch; female uropodal exopods without sharply toothed margins |
|
13 | Male pleotelson with short acute spine (i.e., length subequal to diameter) on basal knob overhanging sinus, interior margins of sinus with 2 pairs of lateral teeth; pleotelson of female elongate, acuminate posteriorly, with 3 dorsal tubercles (Fig. |
|
– | Male pleotelson with large dorsal tubercle at base of sinus, interior margins of sinus with 3 pairs of sharp teeth; female pleotelson not as above (Fig. |
|
14 | Pleotelson apex entire, upturned; dorsal surface of pleotelson with 2 pairs of prominent tubercles and numerous scattered small tubercles; female sculpturing less pronounced than males (see |
|
– | Pleotelson without upturned apex, sculpturing not as above |
|
15 | Pleotelson of males with deeply slit apical notch or expanded foramen, notch may be reduced to small depression or dorsally visible slit in females; uropodal rami subequal in length, typically extending beyond posterior margin of pleotelson; ovigerous females with 1 or 3 pairs of oostegites |
|
– | Pleotelson of males and females with shallow terminal notch; uropodal exopod shorter than endopod, rami not extending beyond posterior border of pleotelson; ovigerous females without oostegites |
|
16 | Pleotelsonic sinus (foramen) distinctly heart shaped with median point in males, but greatly reduced in females; dorsum of pleon with 2 rounded submedian tubercles just lateral to midline on pleonite 5, and 4 similarly spaced tubercles on pleotelson; uropodal rami with crenulated margins (at least in males) (Fig. |
|
– | Pleotelsonic sinus long and narrow, with prominent rounded tubercle barely overhanging anterior base, sinus walls straight sided and finely crenulate; dorsal surface of pleotelson covered with small tubercles; uropodal rami without crenulated margins (Fig. |
|
17 | Frontal margin of head produced as a quadrangular process; antennular articles 1 and 2 dilated; dorsal surface of pleotelson sculptured with 3 longitudinal ridges (Fig. |
|
– | Frontal margin of head not produced; antennular articles not dilated; dorsal surface of pleotelson smooth or tuberculate |
|
18 | Dorsal surface of pleotelson with many tubercles (Fig. |
|
– | Dorsal surface of pleotelson smooth, without tubercles or ridges (Fig. |
|
19 | Uropodal exopods with distinctly serrated outer margins |
|
– | Uropodal exopods with smooth or lightly crenulated outer margins |
|
20 | Dorsal surface of pleotelson lightly sculptured with 2 longitudinal rows of small tubercles, posterior margin with prominent transverse elevation (Fig. |
|
– | Dorsal surface of pleotelson heavily sculptured with many longitudinal rows of small to large heavy tubercles, posterior margin without prominent transverse elevation (Fig. |
|
21 | Dorsal surface of pereonites, pleonites and pleotelson smooth, without tubercles or other ornamentation; apex of pleotelson rounded and truncate (Fig. |
|
– | Dorsal surface of body with ornamentation; apex of pleotelson acuminateEndnote 18 |
|
22 | Pleotelson with produced rhomboid-shaped apical process and concave lateral margins, sides folded inward, forming kind of funnel-like opening when viewed ventrally; dorsum of pleotelson sculptured with 2 basal tubercles, which are continuous with 2 longitudinal ridges that converge posteriorly into a single median ridge; uropods distinctly shorter than pleotelson (Fig. |
|
– | Pleotelson triangular, dorsum without parallel ridges; uropods subequal in length to pleotelson |
|
23 | Dorsal sculpturing subtle, starting on pereonites 6 and 7; pereonite 6 with row of 7 weak tubercles along posterior margin; pereonite 7 with posteriorly directed median process and weak lateral tubercle on each side along posterior margin; pleon with 2 medium tubercles, 1 on each side of midline; pleotelson with 1 strong anteromedial tubercle and 2 weak tubercles lateral to midline (Fig. |
|
– | Dorsal sculpturing distinct on most or all pereonites, comprising either low, weak tubercles or taller, more pronounced tubercles |
|
24 | Dorsal surface of pereonites with low, weak tubercles along posterior margins; pereonite 1 with 1 very weak median tubercle; pereonites 2–4 with 3 tubercles, 1 median and 2 laterals (1 per side); pereonites 5 and 6 with row of 7 tubercles, 1 at midline and 3 laterals per side; pereonite 7 with weak median process and paired lateral tubercles; pleotelson with 2 small anterior tubercles (Fig. |
|
– | Dorsal surface of all pereonites sculptured with heavy, strong tubercles giving body appearance of 7 prominent longitudinal rows of tubercles; pereonite 1 with 2 transverse rows of tubercles; pereonites 2–7 each with 1 transverse row of 7 tubercles; pereonite 7 with strong median process and 3 lateral tubercles per side; pleotelson with 3 strong medial tubercles on either side of midline, plus numerous smaller tubercles scattered over dorsal surface (Fig. |
|
Figs
Comparison of maxillipeds and number of articles in maxillipedal palps (3–5) between genera and families of
1 | Eyes absent; head, pereonites and pleonites with transverse rows of submedian, sublateral and lateral tubercles bearing bead-like spheres; pleotelson with short oblique lateral tubercles; maxillipedal palp 4-segmented (Figs |
|
– | Eyes present; body not as above |
|
2 | Head fused with pereonite 1; pereonite 4 much longer (> 2 ×) than other pereonites; pereonite 4 much broader anteriorly than posteriorly in females; pereopods 1–4 slender, fringed with setae, directed anteriorly against ventral body wall (modified for filter feeding); pereopods 5–7 stout, prehensile; maxillipedal palp 5-segmented (Figs |
|
– | Head distinct from pereonite 1; length of pereonite 4 subequal to other pereonites; anterior pereopods not modified for filter feeding, mostly ambulatory and similar in size |
|
3 | Head incompletely fused with pereonite 1, indicated by distinct lateral incision posterior and ventral to eye (must be viewed laterally); flagellum of antennae with ventral blade-like setae; dorsum of pereonite 4 smooth in males or with medial, bilobed swelling or tubercle in females; dorsum of other pereonites mostly smooth; pleon composed of 3 segments, including 2 pleonites plus the pleotelson (Fig. |
|
– | Head completely fused with pereonite 1, lateral margins entire; flagellum of antennae without blade-like setae; dorsum of pereonites 2–7 typically with 2–4 small to large dorsal spines in females or smooth in males; pleon composed of a single fused pleotelson with 2 anterodorsal median spines |
|
4 | Fused head and pereonite 1 with shallow dorsal transverse groove (fusion line) posterior to eyes; antennae robust with peduncular articles 3 and 4 each ~ 5 × longer than wide; pereonites 2–7 with large, broadly triangulate anterolateral or lateral extensions and a transverse row of 4 large posterodorsal spines; pereonites 4–6 also with medium to large posterolateral spines (Fig. |
|
– | Fused head and pereonite 1 without dorsal transverse groove; antennae relatively long and narrow with peduncular articles 3 and 4 each > 10 × longer than wide; lateral extensions of pereonites 2–7 not as above, and each one with pair of medial posterodorsal spines (size variable); pereonites 5–7 also with 2 smaller distinct lateral spines |
|
5 | Body color typically golden; pereonites 2–4 anterolateral extensions medium in size, broad at base and distally blunt or obtusely rounded; pereonites 5–7 lateral extensions broadly triangular; anterolateral margins of head and antennal peduncular article 1 acute, but not produced forward as recurved spines (Fig. |
|
– | Body color whitish; pereonites 2–7 anterolateral or lateral extensions narrowly triangular and sharply acute; anterolateral margins of head and peduncular article 1 of antennae distinctly produced forward as sharply acute recurved spinesEndnote 20 |
|
6 | Pereopod 4 greatly reduced, non-ambulatory; pleon composed of 4 segments with pair of elevated dorsal humps near posterior end; lateral margins of body with dense tufts of setae (Fig. |
|
– | Pereopod 4 not reduced, all pereopods ambulatory; pleon composed of 1 or 3 segments; dorsal surface of pleon and lateral margins of body not as above | |
7 | Pleon composed of single fused pleotelson, with or without partial suture lines or indentations |
|
– | Pleon composed of 3 to 4 segments, including 1 pair of partial sutures |
|
8 | Pleotelson without suture lines |
|
– | Pleotelson with 1 pair of partial suture lines or indentations |
|
9 | Flagellum of antennae multiarticulate, head with distinct, slightly elongated dorsal tubercle; pereon dorsally smooth (Fig. |
|
– | Flagellum of antennae uniarticulate, flagellar article large and clavate; head with large, multilobed or conical tubercle or elevation; pereonites 1–5 with (female) or without (male) middorsal spines (Fig. |
|
10 | Antennae shorter than or subequal to antennules, antennal flagellum reduced to single vestigial article; maxillipedal palp of 3 articles; pleonal fusion indicated by 1 pair of lateral grooves instead of distinct incisions |
|
– | Antennae much longer than antennules, antennal flagellum multiarticulate or comprising a single, large clavate article; maxillipedal palp of 3 or 4 articles; pleotelson with distinct lateral incisions |
|
11 | Pleotelson with dorsal transverse ridge ca. midway between lateral insertions and posterior border, without dorsal swellings; lateral margins of pereonite 4 in females angular, but not forming acute posterolateral projections; propodi of pereopods with 2 large proximal spines along inferior margins (Fig. |
|
– | Pleotelson inflated or bulbous with large dorsal swellings, without a dorsal transverse ridge; lateral margins of pereonite 4 in females form acute posterolateral projections; propodi of pereopods without large proximal spines along inferior margins (Fig. |
|
12 | Flagellum of antennae uniarticulate, flagellar article large and clavate; head with large, median bifid tubercle projecting anteriorly over frontal margin; anterolateral margins of pereonite 1 produced into bilobed processes (Fig. |
|
– | Antennal flagellum multiarticulate; head and pereonite 1 not as above |
|
13 | Maxillipedal palp 4-segmented (Fig. |
|
– | Maxillipedal palp 3-segmented (Fig. |
|
14 | Eyes large, oval to subpyriform in shape, situated at mid-lateral margins of head; lateral margins of pleotelson flare slightly outward to form obtuse posterolateral angles, after which they taper inwards to strongly acuminate apex; coxal plates of pereonites not visible dorsally (Fig. |
|
– | Eyes small or large, situated laterally on head adjacent to anterolateral angles of pereonite 1; pleotelson not as above, with rounded or obtuse apex; coxal plates of some posterior pereonites visible dorsally |
|
15 | Eyes large; head not deeply immersed in pereonite 1, dorsal surface with a large, medial, apically rounded rostrum-like process; lateral margins of pereon convex, widest around pereonite 4; coxal plates visible dorsally on pereonites 5–7 (or just pereonites 6 and 7); commensal on sea urchins |
|
– | Eyes very small; head deeply immersed in pereonite 1, without a large dorsal process; lateral margins of pereon not convex, generally straight-sided from pereonites 1–4 and then becoming slightly wider from pereonites 5–7; coxal plates visible dorsally on pereonites 4–7 (Fig. |
|
16 | Body smooth, but with triangulate anterior median dorsal pattern on pereonites 2–4; lateral margins of pereonites rounded to straight; posterior margin of pleotelson emarginate (Fig. |
|
– | Body sculptured with conspicuous tubercles or longitudinal rugae; lateral margins of pereonites angular; pleotelson spatulate, rounded posteriorlyEndnote 22 |
|
17 | Lateral margins of adult body roughly parallel, widest part of pereon subequal in width to pleon; pleotelson widest at midpoint; dorsal sculpturing generally reduced to low, conical tubercles on head and medial row of tubercles along pereonites; eyes small and lightly pigmented (Fig. |
|
– | Lateral margins of adult body not parallel, generally widest at pereonites 3 and 4; pleotelson widest anteriorly; dorsal sculpturing variable, pereonites with 3 to 4 longitudinal rugae on lateral areas; eyes large and heavily pigmented |
|
18 | Flange present on basis of pereopods 2–6 in adults, but tiny and difficult to see or not visible in juveniles; anteromedial tubercles of head generally large, highly variable with size, often asymmetrical, becoming broad, flattened, and forward projecting in large specimens; coxae of pereonite 1 not notched laterally; body surface appearing rough, color brownish (Fig. |
|
– | Flange absent on basis of pereopods; anteromedial tubercles not as above, typically smaller, narrowly rounded or conical; lateral margins of pereonite 1 deeply notched in lateral view, separating coxal margins into upper and lower lobes; body surface generally smooth and whitish (Fig. |
|
19 | Maxillipedal palp 4-segmented in adults, article 4 much larger than article 3 (Fig. |
|
– | Maxillipedal palp 5-segmented in adults, article 5 much smaller than article 4 (article 5 may not be developed in juveniles) (Fig. |
|
20 | Eyes large, occupying almost entire lateral margins of head; dorsum of head with curved, sharply defined posterior groove; coxal plates of pereonites 2–7 all wide and extending entire length of respective pereonites; pleotelson broadest anteriorly, tapering to truncate posterior border or apex (Fig. |
|
– | Eyes small, situated mid-laterally on head; coxal plates of pereonites narrow; pleotelson with concave or acuminate posterior border or apex |
|
21 | Posterior margin of pleotelson concave with rounded posterolateral corners; coxae 5–7 reach posterior edges of their respective pereonites (Fig. |
|
– | Posterior margin of pleotelson acuminate, with or without distinct median projection; only coxae 6 and 7 or just 7 reach posterior edges of respective pereonites |
|
22 | Posterior margin of pleotelson triangular, converging to obtuse point; coxae 6 and 7 reach posterior edges of their pereonites; head with apically blunt frontal process (Fig. |
|
– | Posterior margin of pleotelson with an elongate median projection; only coxae 7 reach posterior edge of pereonite 7; head with thin, pointed frontal process (Fig. |
|
23 | Posterior margin of pleotelson deeply concave with acute posterolateral corners (Fig. |
|
– | Posterior margin of pleotelson not concave |
|
24 | Coxae visible dorsally on pereonites 5–7, and occasionally on pereonite 4; posterior margin of pleotelson convex, without median projection; body narrow, with head, pereon and pleotelson subequal in width; apex of frontal process with median notch (Fig. |
|
– | Coxae visible dorsally on pereonites 2–7; posterior margin of pleotelson with short (sometimes poorly developed) to elongate median projection; frontal process with or without apical notch |
|
25 | Pleonite 1 lateral margins curve and taper posteriorly to form narrow, acutely pointed posterolateral angles (margins not parallel) |
|
– | Pleonite 1 lateral margins truncate or convex, more-or-less parallel, not curving posteriorly to form acute points |
|
26 | Pleotelson lateral margins concave, posterior margin with median projection; pereonites widely separated laterally, coxae 2–7 reaching posterior edges of pereonites, anterior margins of pereonite 1 separated from head; eyes rectangular or pyriform; apex of frontal process entire, without notch (Fig. |
|
– | Pleotelson lateral margins convex, broadly rounded, posterior margin with small median projection; pereonites not widely separated laterally, only coxae 5–7 reach posterior edges of pereonites; anterior margins of pereonite 1 flush with head; eyes reniform; apex of frontal process entire, without notch (Fig. |
|
27 | Eyes elongated and thin dorsoventrally; maxilliped with 1–3 coupling hooks; coxae of pereonites 2–7 contiguous with each other (Fig. |
|
– | Eyes not elongated; maxilliped with 1 coupling hook; coxae of at least some pereonites not contiguous with each other |
|
28 | Pleotelson posterior margin with long median projection; lateral margins of pereonite 1 convex; eyes circular to oval; apex of frontal process notched (Fig. |
|
– | Pleotelson posterior margin with small or poorly developed median projection, sometimes appearing slightly truncate; lateral margins of pereonite 1 barely rounded, almost parallel; eyes with straight anterior and convex posterior borders; apex of frontal process entire, without notch (Fig. |
|
Figs
1 | Eyes present |
|
– | Eyes absent |
|
2 | Body (except head) covered with large, jointed-appearing spines; uropods very long if not broken off, with basal segments and rami each ca. as long as width of pleotelson (Fig. |
|
– | Body and uropods not as above |
|
3 | Eyes sessile, situated dorsolaterally on head but not reaching lateral margins; pleotelson subequal in width to cephalon and most pereonites |
|
– | Eyes situated laterally on head, bulging outward on short to elongated ocular lobes or peduncle-like projections; pleotelson distinctly narrower than cephalon and widest pereonites |
|
4 | Head with rounded anterolateral margins and prominent rounded median lobe between antennae; body widest at ca. pereonite 6; adult body length < 3 mm; commensal on or in burrows of sphaeromatid |
|
– | Head not as above; body lateral margins parallel or gently convex and slightly widest around mid-pereon; maximum adult length varies between ~ 1.3–7.3 mm |
|
5 | Body elongated and unpigmented, lateral margins parallel and covered with long simple setae; head with acute anterolateral angles and lightly pigmented eyes; pleotelson shield-like with small posterolateral spines; male pereopod 1 strongly subchelate with thick projection on inferior margin of propodus, and many long simple setae on dactylus, propodus, carpus, and merus (Fig. |
|
– | Body, head, and male pereopod 1 not as above |
|
6 | Uropods short, inserted in subterminal excavations of pleotelson and not extending much beyond its posterior margin; both antennules and antennae small, flagella lacking or rudimentary; peduncle articles of antennae dilated | |
– | Uropods well-developed, extending well beyond posterior margin of pleotelson; both antennules and antennae relatively long with multiarticulate flagella, although flagella often broken off in preserved specimens; peduncle articles of antennae not dilated | |
7 | Body without pigment, covered with numerous fine simple setae |
|
– | Body typically pigmented, not covered with fine setae |
|
8 | Body elongated and parallel-sided (L:W ratio ~ 4.3); head with distinct indentation on lateral margins below eyes; basal article of antennules with large, outwardly produced distolateral projection bearing ~ 6 sharp, flat spines curving toward article 2; pleotelson lateral margins with 7 large posteriorly curved spines, rest of body with small denticulations on lateral margins (Fig. |
|
– | Body broad and laterally curved (L:W ratio ~ 2.6); margins of head produced forming large lateral plate, with ~ 9 anteriorly curved spines, eyes not reaching lateral margins; basal article of antennules with small distolateral process bearing several lateral curving flat spines; pleotelson with 8 posteriorly curved spines (Fig. |
|
9 | Lateral margins of pleotelson without spines; body banded in appearance, with dark brown pigment typically covering head, pereonites 2–4 and 7, and pleotelson; maxillipedal palp article 2 not produced medially; anterior margin of frontal lamina entire, without fringe of small scales (Fig. |
|
– | Lateral margins of pleotelson with 3–7 spines; body typically with diffuse pigment, which may be most pronounced on head and pereonite 4; maxillipedal palp article 2 produced medially; anterior margin of frontal lamina with fringe of small scales |
|
10 | Lateral margins of pleotelson with 5–7 spines; head typically heavily pigmented, pereon and pleon lightly pigmented or without pigments (Fig. |
|
– | Lateral margins of pleotelson with 2 or 3 spines; head and pereonite 4 both typically heavily pigmented but compare pigment pattern of head with that of |
|
11 | Pereopod 1 with conspicuous serrations or denticles on proximal third of inferior margin of propodus; maxillipedal palp articles 1–3 as wide as endite |
|
– | Pereopod 1 without denticles on proximal third of inferior margin of propodus; maxillipedal palp articles 2 and 3 much wider than endite |
|
12 | Pleotelson with distinct distolateral angles or spines; head with pointed anterolateral margins and distinct rostrum |
|
– | Pleotelson without distolateral spines, posterolateral margins rounded; head with pointed or rounded anterolateral margins, with or without rostrum |
|
13 | Adults with acutely pointed rostrum extending well beyond anterior limits of anterolateral margins of head; body completely devoid of pigment (Fig. |
|
– | Adults with rostrum not extending anteriorly beyond anterolateral margins of head; body pigmented |
|
14 | Head with acute rostral point; posterior margin of pleotelson concave laterally with convex median lobe that does not extend beyond posterior limits of distolateral spines; species lives commensally on sun stars ( |
|
– | Head with obtuse rostral point; posterior margin of pleotelson with convex lateral areas and obtusely rounded median point that extends posteriorly distinctly beyond limits of distolateral spines |
|
15 | Body covered with diffuse, anastomosing chromatophores, with pigment extending into region anterior to eyes (Fig. |
|
– | Body covered with dense, non-anastomosing chromatophores that are absent from region anterior to eyes (Fig. |
|
16 | Head with angular anterolateral margins and short, acute median lobe or slightly rounded median point; eyes medium to large, dorsal, clearly separated from lateral margins of head; body relatively short and broad (L:W ratio < 2.5); pleotelson nearly 2 × as wide as long |
|
– | Head with rounded anterolateral margins, without distinct median lobe or rostrum; eyes large, almost touching lateral margins of head; body long and narrow (L:W ratio > 3.0); pleotelson ca. as wide as long |
|
17 | Dorsal surface with numerous black chromatophores; pereonites 1–3 with distinct lateral lobes or lappets, each pair separated by narrow V-shaped slit; all lateral margins with conspicuous setal fringe; posterolateral margins of pereonites 5–7 angular; pereonite 5 not shorter medially than other pereonites (Fig. |
|
– | Dorsal surface without pigment, but with many fine setae; pereonites 2 and 3 with short anterior lappets and indistinct posterior lappets; lateral margins without conspicuous setal fringe; posterolateral margins of pereonites 5–7 rounded; pereonite 5 distinctly shorter medially than other pereonites (Fig. |
|
18 | Body whitish, without distinct chromatophores; pereopod 1 propodus with ~ 12 or 13 denticles on proximoventral border (Fig. |
|
– | Body pigmented with numerous dense chromatophores; pereopod 1 propodus with ~ 18 denticles on proximoventral border (Fig. |
|
19 | Lateral margins of pleotelson with spine-like serrations |
|
– | Lateral margins of pleotelson without serrations, although setae may be present |
|
20 | Pleotelson with 4–7 spine-like serrations on each side (Fig. |
|
– | Pleotelson with 3 spine-like serrations on each side (Fig. |
|
21 | Pleotelson with distinct posterolateral angles extended beyond uropodal insertions (Fig. |
|
– | Pleotelson without posterolateral angles, posterior margins rounded |
|
22 | Uropods relatively short, not exceeding half-length of pleotelson; frontal margin of head truncate (Fig. |
|
– | Uropods much longer than half-length of pleotelson; frontal margin of head with short pointed or blunt medial lobe |
|
23 | Uropods very long, exceeding length of pleotelson; lateral apices of male pleopod 1 bifurcate (Fig. |
|
– | Uropods not exceeding length of pleotelson; lateral apices of male pleopod 1 not bifurcate (Fig. |
|
24 | Pereonites 1–3, 5 and 6 with long, finger-like lateral processes, each with 1 or 2 terminal setae; pleotelson bulbous anteriorly, then tapers posteriorly to a narrow truncate end; uropods inserted dorsolaterally on anterior half of pleotelson, each uropod ca. as long as pleotelson; eyes tiny, each composed of two lenses at tip of very long and thin lateral peduncle or lobe (Fig. |
|
– | Pereonites, pleotelson and uropods not as above; eyes situated at tips of short to elongated ocular lobes |
|
25 | Antennules and antennae both long, subequal in length; frontal margin of head broadly rounded | |
– | Antennae > 2 × longer than antennules; frontal margin of head broadly truncate, with or without medial concavity | |
26 | Pereonites 1–3 with dorsal posterolateral setal tufts; pleotelson as wide or wider than pereonite 7, lateral margins of pleotelson serrate or denticulate anterior to uropodal insertions, denticulations with embedded compound setae in cusps (Fig. |
|
– | Pereonites without dorsal setal tufts; pleotelson narrower than pereonite 7, lateral margins convex without lateral serrations or denticulations |
|
27 | Body broadly ovate with pereonites 2 and 3 distinctly wider than pereonites 4 and 5 (body L:W ratio ~ 1.6); head deeply immersed in pereon with pereonite 1 much longer (male) or subequal (female) in length to pereonite 2; eyestalk (ocular lobe) much longer than article 1 of antennules; coxae visible in dorsal view only on pereonites 5–7 (Fig. |
|
– | Body narrower than above with pereonites 2–5 subequal in width (body L:W ratio > 2.0); head not deeply immersed in pereon, with pereonite 1 shorter than pereonite 2 in both sexes; ocular lobes much shorter than article 1 of antennules; coxae visible in dorsal view on at least pereonites 2–7 |
|
28 | Article 1 of antennules shorter than article 2; pereopod 2 in males with robust subtriangular projection on distoventral corner of basis, and proximal projection on ischium; pereopod 2 ventral margins of propodi with short robust setae (Fig. |
|
– | Article 1 of antennules subequal in length or longer than article 2; pereopod 2 in males not as above, without distinct projections on basis and ischium; pereopod 2 ventral margins of propodi with simple setae only (Fig. |
|
29 | Pleotelson with 4–6 spines or serrations on ventrolateral margins; male pleopod 1 apically pointed (Fig. |
|
– | Pleotelson without spines on lateral margins; male pleopod 1 with apices laterally expanded |
|
30 | Pleotelson with concave posterolateral margins; posterior border of pereonite 7 convex (Fig. |
|
– | Posterolateral margins of pleotelson not concave, although small indentations may be present around uropodal insertions; pereonite 7 with deeply concave posterior border wrapping around anterior portion of pleotelson |
|
31 | Uropods with large acute spine-like protuberances on distal margins; pleotelson posterior margin without subanal channel or shelf visible in dorsal view |
|
– | Uropods without spine-like protuberances on distal margins; pleotelson with or without subanal shelf visible in dorsal view |
|
32 | Lateral margins of pleotelson with 2 or 3 backwards-curved robust sensory setae on each side; pleotelson broad medially, nearly as wide as long (Fig. |
|
– | Lateral margins of pleotelson without robust sensory setae; pleotelson narrow, much longer than wide (Fig. |
|
33 | Frontal margin of head with ~ 8 stout, 2-pointed spines; lateral margins of pereonites 1–6 with stout spines; pleotelson without subanal shelf (Fig. |
|
– | Margins of head and pereonites without spines, although setae may be present; pleotelson with subanal shelf visible in dorsal view |
|
34 | Eyes small, occupying ca. half of short ocular lobes; body surfaces smooth, not covered with setae; uropods tiny, hidden within short, broad subanal shelf (Fig. |
|
– | Eyes large, occupying most of prominent ocular lobes; all dorsal surfaces covered with fine simple setae; uropods larger and clearly visible, not hidden by subanal shelf |
|
35 | Subanal shelf short and broad, reaching but not obscuring uropods; male pleopod 1 with large sensillate setae on ventral surface (Fig. |
|
– | Subanal shelf elongated posteriorly, but no wider than anus and not reaching or extending under uropods; male pleopod 1 with short simple setae on ventral surface (Fig. |
|
36 | Surface of body covered with many small spines and fewer large spines; dorsal surface of pleotelson with pair of large stout posterior protuberances, each with 3 large distal spines (Fig. |
|
– | Surface of body and pleotelson not as above |
|
37 | Pereopods 5–7 expanded and natatory, with enlarged, paddle-like carpi and propodi; posterior body arranged as distinctive natasome, consisting of partially or completely fused pereonites 5–7 and the pleotelson | |
– | Pereopods 5–7 without enlarged, paddle-like carpi and propodi; posterior part of body without distinct natasome |
|
38 | Head with bilobed or pointed rostrum projecting anteriorly between antennules |
|
– | Head without rostrum extending between antennules |
|
39 | Head with broad, indented (bilobed) rostrum; natasome flattened, tapering; pereonites 5 and 6 fused dorsally; pereonite 7 smaller and narrower than pereonites 5 and 6 (Fig. |
|
– | Head with narrow, roundly pointed rostrum, not bilobed; natasome robust and deep; pereonites 5 and 6 not fused dorsally; pereonite 7 larger than pereonites 5 and 6 (Fig. |
|
40 | Natasome not triangular, pleotelson inflated dorsally with relatively straight lateral margins; pereonites 5–7 subequal in size; uropodal protopod small, tubular |
|
– | Natasome triangular, lateral margins of pleotelson taper to pointed apex; pereonite 7 distinctly narrower than pereonites 5 and 6; uropodal protopod large, flattened |
|
41 | Head subequal in width to pereonite 1; small species, with body length of adults < 2 mm (Fig. |
|
– | Head very large, distinctly broader than pereonite 1; much larger species than above, with body length of adults reaching 7 mm (Fig. |
|
42 | Anterior margins of pereonites 1–4 with large pedestal setae (Fig. |
|
– | Anterior margins of pereonites 1–4 with small, non-pedestal setae (Fig. |
|
43 | Body with conspicuous setal fringe on lateral margins; head trilobate anteriorly; pleotelson wider than long with concave posterior margins at uropodal insertions and blunt median apex; basal article of antennules greatly expanded; article 3 of antennae with elongate, setiferous scale; small intertidal isopods that live in burrows in wood excavated by limnoriid isopods (Fig. |
|
– | Body and habitat not as above |
|
44 | Body greatly elongated, > 6 × longer than wide; lateral margins generally parallel with head, pereonal, and pleonal segments subequal in width |
|
– | Body not as long as above, ≤ 4.5 × longer than wide; lateral margins distinctly not parallel |
|
45 | Antennae with strong scale on peduncular article 3; uropods long and distinct, protopod subequal in length to pleotelson and half as wide, sides parallel until pinching off slightly towards distal medial tip; uropodal endopod ca. one-third length of protopod and attached subapically; uropodal exopod ca. half-length of endopod and attached more laterally near where protopod begins to curve inwards (Fig. |
|
– | Antennae without scale on peduncle; uropods styliform, not as above (Fig. |
|
46 | Integument of body with complete and prominent scaling; peduncular article 2 of antennules with ≥ 3 strong longitudinal ridges; mandibles whitish, not appearing sclerotized; setal comb present on posteroventral margin of basis of anterior pereopodsEndnote 28 |
|
– | Body with very light and intermittent scaling; peduncle of antennules without longitudinal ridges; mandibles brownish, heavily sclerotized; setal comb absent on posteroventral margins of basis of anterior pereopodsEndnote 28 |
|
47 | Pereonite 7 fused dorsally with pleotelson; body widest at posterior third of pleotelson; posterior margins of pleotelson with large bilobed medial extension and large tooth on each lateral edge (Fig. |
|
– | All pereonites dorsally free; body widest at anterior half of pereon; pleotelson not as above |
|
48 | Body long and narrow (L:W ratio ~ 4.5); pereonites 1–3 only slightly wider than head and pleotelson | |
– | Body short and broad (L:W ratio ≤ 2.0); pereonite 1 and usually pereonites 2–6 much wider than head and pleotelson | |
49 | Pereonite 1 distinctly larger than pereonite 2, with large ventral median spine; posteriorly curving ventral median spines also present on pereonites 3 and 7; pleotelson posteriorly rounded, with large subdistal ventrolateral spines (Fig. |
|
– | Pereonite 1 subequal or smaller than pereonite 2; ventral median spines absent on all pereonites |
|
50 | Pereonite 1 subequal to pereonite 2; head with anterolateral spines; pleotelson with posterolateral spines or angles and a rounded posterior medial border; uropods biramous (Fig. |
|
– | Pereonite 1 smaller than pereonite 2; head without anterolateral spines; pleotelson without posterolateral spines; uropods uniramous, lacking exopods (Fig. |
|
51 | Lateral margins of pleotelson serrate with numerous denticulations or spines; coxae of pereonites not visible dorsally |
|
– | Lateral margins of pleotelson smooth, without denticulations or spines; coxae visible dorsally on pereonites 2–7, most or all with single large projecting spine |
|
52 | Anterior margin of head broadly quadrate with rounded anterolateral angles; lateral margins of pereonites heavily denticulate; pleotelson ca. as wide as long, lateral margins completely serrate; uropods inserted on posterolateral margins of pleotelson (Fig. |
|
– | Anterior margin of head with strongly produced and rounded anterior margin; lateral margins of pereonites with or without denticulations or spines; uropods inserted slightly dorsally on pleotelson |
|
53 | Head with 2 granulate tubercles above antennal bases; body widest at pereonite 1; lateral margins of pereonites serrate, anterior-most tooth enlarged and pointed forward on pereonites 1–3; pleotelson dentate along basal two-thirds of lateral margins, with 2 strong teeth located on rounded end where uropods would typically be inserted (Fig. |
|
– | Head without granulate tubercles; body widest at pereonites 2 and 3; lateral margins of pereonites without denticulations or spines; pleotelson with serrated lateral margins, although the details are undocumentedEndnote 29 |
|
54 | Basal articles of antennules with large curved anterolateral projections; body surface rough with apparent microscales; projecting spine on each coxa of pereonite 7 typically large and conspicuous (Fig. |
|
– | Antennules without anterolateral projections on basal articles; surface of body smooth to slightly scaled; coxal spines of pereonite 7 reduced or absent (Fig. |
|
Figs
1 | Uropods ventral and operculate covering pleopods, not visible in dorsal view; body able to roll up into a ball (conglobate) (Fig. |
|
– | Uropods terminal, visible in dorsal view; body may or may not be able to conglobate |
|
2 | Flagellum of antenna with > 10 articles; eyes large with > 50 ommatidia each, and wrapping around lateral margins of head, distance between eyes equal to length of 1 eye; isopods unable to conglobate (Fig. |
|
– | Flagellum of antenna with 2–4 articles; eyes not as above, much smaller (< 30 ommatidia) and not wrapping around lateral margins of head; isopods may or may not be able to conglobate |
|
3 | Flagellum of antenna with 2 or 3 articles; head without large anterolateral lobes |
|
– | Flagellum of antenna with 4 articles; head with very large, distinctly produced anterolateral lobes, each lobe broad and truncate at tip |
|
4 | Flagellum of antenna with 2 articles; dorsal surface of body covered with fine, but distinct scales (Fig. |
|
– | Flagellum of antenna with 3 articles; dorsum without distinctly visible scales |
|
5 | Head with small, forward protruding cone-shaped lobes situated just anterior to eyes; frontal margin of head produced into blunt median lobe; pleon not abruptly narrower than pereon |
|
– | Head without cone-shape lateral lobes anterior to eyes; frontal margin of head slightly sinuous, but not produced into median lobe; pleon abruptly narrower than pereon (Fig. |
|
6 | Uropodal protopod with rounded and expanded posterolateral margins (Fig. |
|
– | Uropodal protopod with oblique posterolateral margins, not produced (Fig. |
|
7 | Anterior margin of head produced into strong, truncate median lobe; body markedly convex and capable of conglobation (Fig. |
|
– | Anterior margin of head produced into sharply acute median lobe; body not markedly convex and not capable of conglobation |
|
8 | Dorsal surface of body covered with large, elevated tubercles best developed on head; posterior border of all body segments except pleotelson appear beaded with minute, evenly spaced tubercles; antennal peduncle article 4 with spur-like process on lateral margin (Fig. |
|
– | Dorsal surface of body rough, with low, rounded tubercles; posterior border of all body segments smooth; antennal peduncle article 4 without spur-like process on lateral margin (Fig. |
|
The provisional species Sphaeromatidae sp. A listed in
No illustrations exist for the provisional anthuroid
The aegid
It is currently unclear how to clearly distinguish juveniles of most cymothoid species from each other. Although
Since its description in 1980, the cymothoid
The cymothoid
Female and juvenile gnathiids key only to family in Key D. However,
No illustrations exist for the three provisional species of gnathiids included in Key D (
The provisional species
The bopyrid
Two different adult body morphologies have been described for the dajid isopod
Specimens of unidentified dajid isopods listed as
There may be a new species of
Deep-water specimens have a much larger dorsal carina than do shallow-water animals. This is like differences described by
Deep-water specimens have a rather shallow lateral notch on the pleotelson that does not form a well-defined tooth (like described for
Pereonites 5 and 6 are subequal in width to pereonite 4 in the deep-water animals (the lateral margins are nearly continuous with a gradual tapering to the pleotelson). In contrast, there is a distinct narrowing of the pereon between pereonites 4 and 5 in the shallow-water animals. This difference in shape appears distinct even in juveniles.
Two species of the sphaeromatoid genus
Although the sphaeromatid
Even though the couplet in Key G identifying the sphaeromatid
The sphaeromatids
Species of the sphaeromatid genus
Even though the sphaeromatid
Three species of the valviferan genus
The three species of
The idoteid isopods
Although no illustrations exist of the provisional asellote species
The provisional asellote species
No illustrations exist for the SCB asellotes
No illustrations exist for the provisional species
The marine habitats of the Southern California Bight (
Diversity of isopods by habitat type in the Southern California Bight. Data are expressed as the number of species per taxon occurring in each habitat. Intertidal habitats include outer coast rocky shores and sandy beaches, as well as soft and hard substrates along the edges of marshes, bays, and estuaries. Subtidal habitats include shallow bays and estuaries, plus shallow to deep waters of the continental shelf, slope, basins, and submarine canyons.
Taxon | Intertidal | Bays & estuaries | Shelf, slope, basins, canyons | ||
---|---|---|---|---|---|
< 200 m | 200–1000 m | > 1000 m | |||
|
|
|
|
|
|
Superfamily |
4 | 2 | 10 | 2 | 1 |
Superfamily |
8 | 1 | 24 | 14 | 5 |
Infraorder |
|||||
Superfamily |
7 | 4 | 11 | 1 | 1 |
Superfamily |
1 | – | 2 | 2 | 1 |
|
|
– |
|
– | – |
|
|
|
|
– | – |
Superfamily |
1 | 1 | 1 | – | – |
Superfamily |
21 | 3 | 15 | – | – |
|
|
|
|
|
|
|
|
|
|
|
|
Superfamily |
17 | 1 | 32 | 18 | 5 |
Superfamily |
– | – | 1 | – | – |
|
|
– | – | – | – |
|
|
|
|
|
|
Overall, 190 species of isopods are recognized in this review as likely to occur in the
Approximately 22% of the isopods treated herein (41 species) appear restricted to
Twenty-seven of the
Some species may have been introduced multiple times, and others have become established residents in their new localities with expanding ranges. For example, based on mitochondrial data, the sphaeromatid
Another sphaeromatid,
We also recognize the shortcomings of reproducing dorsal view line drawings for most species yet are grateful to previous authors for their efforts. Although dorsal views have long been the accepted standard depiction for isopods, such views are often not especially useful for identifying some species. For example, identification of some asellotes and arcturid valviferans would greatly benefit from lateral views. Ventral views depicting the pleotelson features of valviferans and sphaeromatids would also improve and simplify many identifications. However, such views do not exist for most taxa. High quality color photographs of live specimens would also be a vast improvement in facilitating accurate species identifications. Fortunately, with the increasing popularity of community platforms such as iNaturalist, in-situ color photographs of live animals are helping to expand our knowledge of species distributions, as well as contributing new and valuable habitat information. As videos of living specimens become more common, insights into the behavior and habitat use of species should also improve.
Several other active projects are also moving forward that should further our understanding of the biodiversity and taxonomy of many groups. For example, the National Science Foundation’s digitization efforts of natural history museum collections, such as the current 4-year effort underway at the Natural History Museum of Los Angeles County in southern California (DigIn:
The next step, just now beginning, is to knit the systems above (and others like them) into an integrated architecture of biodiversity knowledge. The goal is to realize the ideals expressed in the emerging “Extended Specimen” concept (see
The following people are gratefully acknowledged for their assistance in completing this review of the
This is Contribution Number 14 of the NHM Diversity Initiative of the Southern California Ocean (DISCO).
Systematic treatment and geographic distribution summary for Southern California Bight marine isopods (
Taxon | Eastern Pacific Distribution |
---|---|
|
|
Superfamily |
|
Family |
|
|
|
Family |
|
Northern |
|
British Columbia – San Quintin Bay, |
|
Family |
|
|
|
Family |
|
~ 35 km north of |
|
Family |
|
Northern |
|
Northern |
|
Northern |
|
Superfamily |
|
Family |
|
Central |
|
Aleutian Islands – Peru (+ West Pacific) | |
Bering Sea – Gulf of |
|
Alaska – Gulf of |
|
Central |
|
Central |
|
Northern |
|
Family |
|
British Columbia – Magdalena Bay, |
|
British Columbia – |
|
Oregon – |
|
British Columbia – |
|
Family |
|
Family |
|
Alaska – Peru | |
Coronado Islands, |
|
Oregon – Columbia | |
|
|
Family |
|
British Columbia – |
|
British Columbia – |
|
|
|
|
|
|
|
|
|
|
|
British Columbia – |
|
British Columbia – |
|
British Columbia – |
|
|
|
Family |
|
Central |
|
|
|
Infraorder |
|
Superfamily |
|
Family |
|
Central |
|
Northern |
|
Bering Sea – |
|
|
|
Central |
|
|
|
Bering Sea – |
|
Central |
|
British Columbia – |
|
British Columbia – |
|
British Columbia – Gulf of |
|
Family |
|
British Columbia – Gulf of |
|
Superfamily |
|
Family |
|
Alaska – |
|
|
|
Family |
|
British Columbia – |
|
|
|
Superfamily |
|
Family |
|
British Columbia – |
|
Northern |
|
Washington – Mazatlán, |
|
|
|
Superfamily |
|
Family |
|
Superfamily |
|
Family |
|
Washington – |
|
Family |
|
Washington – |
|
Oregon – |
|
Washington – |
|
Northern |
|
|
|
Washington – |
|
|
|
Washington – |
|
Northern |
|
British Columbia – Central |
|
Aleutian Islands – |
|
Northern |
|
Central |
|
Northern |
|
Northern |
|
Family |
|
Washington – |
|
|
|
Family |
|
Central |
|
British Columbia – |
|
|
|
Family |
|
Family |
|
Oregon – |
|
British Columbia – Gulf of |
|
|
|
|
|
Alaska – |
|
Alaska – Baja |
|
Alaska – Gulf of |
|
British Columbia – Gulf of |
|
Oregon – |
|
Alaska – Baja |
|
Alaska – Gulf of |
|
Bering Sea – |
|
Alaska – Gulf of |
|
Aleutian Islands – Gulf of |
|
|
|
Oregon – Costa Rica (+ Japan) | |
Central |
|
British Columbia – |
|
Family |
|
|
|
|
|
Superfamily |
|
Family |
|
|
|
Family |
|
~ 89 km north of |
|
Northern |
|
Northern |
|
Family |
|
|
|
Family |
|
|
|
|
|
Northern |
|
Washington – |
|
Bering Sea – |
|
Bering Sea – |
|
Northern |
|
Northern |
|
British Columbia – Chile (+ Korea) | |
Central |
|
British Columbia – |
|
Central |
|
Alaska – |
|
|
|
|
|
~ 35 km north of |
|
~ 35 km north of |
|
Family |
|
Central |
|
British Columbia – Gulf of |
|
Northern |
|
Oregon to |
|
~ 30 km north of |
|
Family |
|
|
|
Family |
|
British Columbia – |
|
Washington – |
|
Northern |
|
|
|
|
|
Bering Sea – |
|
|
|
British Columbia – Gulf of |
|
Family |
|
|
|
|
|
Northern |
|
Northern |
|
|
|
|
|
Family |
|
|
|
Family |
|
|
|
|
|
Central |
|
|
|
|
|
|
|
|
|
British Columbia – |
|
|
|
Family |
|
Central |
|
Superfamily |
|
Family |
|
~ 35 km north of |
|
|
|
Superfamily |
|
Family |
|
Northern |
|
British Columbia – Magdalena Bay, |
|
Family |
|
Northern |
|
British Columbia – Magdalena Bay, |
|
Northern |
|
Family |
|
British Columbia – Isla Cedros, |
|
Family |
|
Family |
|
Washington – Chile (+ |
|
Family |
|
† Taxon inquirendum (genus uncertain for