Corresponding author: Adam R. Wall (
Academic editor: S. Taiti
Wall AR, Bruce NL, Wetzer R (2015) Status of
The
The North American western coast lies within the East Pacific biogeographic zone, and the
One such poorly-known North American species is
We redescribe
LACM–Natural History Museum of Los Angeles County; USNM–United States National Museum, Smithsonian Institution; BM–British Museum; MCZ–Museum of Comparative Zoology Harvard, ANSP–Academy of Natural Sciences Philadelphia; UAF–University of Alaska, Fairbanks; AM–Amherst College, Massachusetts; PM–Yale Peabody Museum, Connecticut; RS–robust seta/e; PMS–plumose marginal setae; SEM–scanning electron microscopy; SCAMIT–Southern California Association of Marine Invertebrate Taxonomists. Latitudes and longitudes denoted with “~” are approximate and estimated from Google Earth.
Descriptions are based on the male holotype, female allotype, and topotypic paratypes. Specimens examined have been assigned a USNM or LACM catalog/type numbers. Numbers preceded by “RW” are field and station numbers. Species descriptions were prepared using DELTA (
Specimens prepared for SEM were cleaned for 10–20 seconds in a Branson 1200 ultrasonic cleaner in a weak solution of Branson GP jewelry soap and distilled water. Specimens were then dehydrated with 100% ethanol. Specimens were placed in solutions of pure ethanol and distilled water in the ratios 2:1, 1:1, 1:2, and finally into 100% ethanol (20 minutes per treatment). Once dehydrated and in 100% ethanol, hexamethyldisilzane (HMDS) was used to replace the ethanol in the specimens. Specimens were transferred through ethanol and HMDS solutions in the following ratios 2:1, 1:1, 1:2 and finally into 100% HMDS (20 minutes per treatment). Specimens were transferred from the final 100% HMDS to fresh HMDS and allowed to evaporate overnight. Specimens were mounted on carbon conductive tabs and coated with gold/palladium using an Emitech K550x sputter coater (Quorum Technologies, LTD, Kent, UK) and imaged using a Hitachi S-3000N variable pressure SEM (Hitachi, Troy, MI) at the LACM.
Drawings were made with the aid of a camera lucida and illustrations were electronically “inked” with Adobe Illustrator CS6. Whole body illustrations were made with a Wild M5D stereo dissecting scope. Appendages were illustrated by dissecting off the appendage and placing them in glycerol on a depression slide and then imaged using a Nikon Labophot-2 compound scope.
Specimens were measured by tracing their dorsal surface along their longitudinal axis with the aid of a camera lucida. A scale bar in the same plane as the specimens allowed calculation of total body length. All lengths reported were mesured in this fashion and may slightly overestimate total body length because pereonites and pleonites are expanded in this position. The lengths given in the “Material Examined” are of the largest specimen of each species and sex. Not all specimens were measured. If a length is provided and multiple specimens were present in a lot, the length refers to largest specimen. In all species mature males appear larger than females, but body lengths for mature adults are similar. Males in all species have much broader uropods than females, which contributes to this illusion. Large sexually mature males tend to be rare compared to females and subadults. Gravid females are rare. Smaller non-gravid individuals cannot be sexed. Females of the different species are virtually indistinguishable and cannot be confidently assigned to a species without an accompanying male. It appears that the largest males guard harems. No individual male-female mate guarding was observed (as occurs in
We provide dorsal and lateral line drawings of all males for each species. We also provide dorsal and lateral SEMs of both males and females of each species.
This key is based on adult ♂ characters. Also note that weak pereon tubercles are visible only with SEM and not necessarily evident with light microscopy – e.g., compare Figures
1 | Pereonites 1–7, pleon, and pleotelson without ornamentation; pleotelson to overall body length ratio 0.21; apex of posterior margin of pleotelson rounded and truncate; uropodal endopods posterior margin evenly rounded; sex ratio nearly 1:1; individual mate guarding | |
– | Pleon with tubercles; pleotelson and uropods long, pleotelson to overall body length ratio 0.30 or greater; posterior margin of pleotelson acuminate; uropodal endopods posterior margin falcate; large adult males rare, one alpha male guarding many females and juveniles (harem guarding) |
|
2 | Pereonites 5–7 without tubercles; pleon with 1 anterior and 1 posterior weak tubercles on either side of longitudinal axis; pleotelson dorsal surface without ornamentation; appendix masculina straight, distally narrowing, distal apex acute, length 16.0 basal width | |
– | Pereonite 7 with weak or strong median process; pleon with 1 medium tubercle on either side of longitudinal axis; pleotelson dorsal surface with tubercle |
|
3 | Pereonites 5 and 6 without ornamentation, pereonite 7 with weak median process; pleon with 1 medium tubercle on either side of longitudinal axis; pleotelson dorsal surface with 2 small anterior tubercles; appendix masculina distal end curving mesially, apex weakly hooked mesially, length 11.4 basal width | |
– | Pereonite 5 without ornamentation, pereonite 6 with 1 lateral weak tubercle, pereonite 7 with weak median process, and paired weak lateral tubercles; pleon with 1 medium tubercle on either side of longitudinal axis; pleotelson dorsal surface with 1 anterior median strong tubercle and 2 weak medial tubercles; appendix masculina apically narrowly rounded, length 13.0 basal width | |
– | Pereonites 5 and 6 with tubercles; pereonite 7 with median process, and tubercles; pleon with 1 posterior strong tubercle, on either side of longitudinal axis; pleotelson dorsal surface with tubercles |
|
4 | Pereonites 5 and 6 with 1 median weak tubercle, and 1 weak lateral tubercle; pereonite 7 with weak median process and paired lateral tubercles; pleotelson dorsal surface with 2 small anterior tubercles; appendix masculina distal end curving mesially, straightening at distal tip, length 15.4 basal width | |
– | Pereonites 5–6 each with 7 longitudinal rows of strong tubercles, pereonite 7 with strong median process with 3 lateral tubercles; pleotelson dorsal surface with 3 strong medial tubercles on either side of the longitudinal axis, with 1 strong medial tubercle between the longitudinal axis and lateral margin, pleotelson covered with numerous, additional, small tubercles; appendix masculina distally narrowing to an acute rounded tip, length 15 basal width |
A diagnosis and comprehensive synonymy was provided by
Other
The type specimens of
In collections from the type locality at Tomales Bay in 2009 for
NEOTYPE (here designated): ♂ (5.1 mm): California, Marin County, Tomales Bay, north end of bay across from Hog Island, boat launch parking lot,
We searched all probable museum collections for Stimpson’s type specimens, but to no avail (see Acknowledgements). It is highly likely that the type specimens are lost. The original and subsequent description (
We borrowed the types of
California: Marin, Sonoma, and San Mateo Counties.
HOLOTYPE: ♂ (7.8 mm): Alaska, Aleutian Islands, Kiska Harbor,
PARATYPES: Allotype: ♀ (8.6 mm, whole animal figured): same locality as USNM 1251663, USNM 1251664. 1 ♂, 9 ♀, 2 juveniles, plus 1 ♂ and 1 ♀ prepared as SEM: all same locality as USNM 20474. 8 ♂ (8.0 mm), 1 ♂ broken: north coast of Amchitka,
Largest ♂ 8.0 mm, largest ♀ 8.6 mm.
Without chromatophores. Preserved specimen pale cream.
Alaska, Aleutians.
This species is named to honor LACM Trustee and long supporter of science at the Natural History Museum of Los Angeles County, Joan Payden. She is thanked for her gracious philanthropy which in part supported ARW as an undergraduate student researcher. ARW’s research experience describing and redescribing the
HOLOTYPE: ♂ (7.0 mm): Washington, Puget Sound, Seattle, Puget Sound Naval Supply Depot, Smith Cove,
PARATYPES: Allotype gravid ♀ (6.7 mm): same data as holotype, LACM CR-2014.6. 1 ♂ dissected, appendages figured (RW04.010.3), 1 ♂ (RW04.010.4, LACM CR-2014.6.4) and 2 ♀ (6.7 mm RW04.010.5, LACM CR-2014.6.5) prepared as SEM, plus ~70 additional specimens (all life stages RW04.010.6): same locality as RW04.010, LACM CR-2014.6. 3 ♀ (7.2 mm), 1 subadult ♂: south end of San Juan Island, Cattle Point,
Largest ♂ 8.3 mm, largest ♀ 8.7 mm.
Without chromatophores. Preserved specimen pale buff, whitish.
Washington, Puget Sound and San Juan Island.
Named to honor Russell Kenneth Hanson, ARW’s only maternal uncle who has shaped the person Adam is today by so graciously sharing with Adam his insatiable curiosity, life-long pursuit of perfection and tireless work ethic.
HOLOTYPE ♂ (4.6 mm): California, Los Angeles County, Palos Verdes Peninsula, Pt. Fermin, shore at Paseo del Mar, ~0.5 mi. W of Gaffey Street,
PARATYPES: Allotype ♀ (4.6 mm) (whole animal figured): shore at Paseo del Mar, ~0.5 mi. W of Gaffey Street,
Largest ♂ 6.8 mm, largest ♀ 4.6 mm.
No chromatophores: preserved specimen pale buff, whitish.
California, Los Angeles County, Palos Verdes Peninsula.
This beautiful species is named for N. Dean Pentcheff, expert isopod collector, superb field and dive buddy, travel companion and IT support par excellence. Dean is commended for his reliable patience, support and solid friendship.
LECTOTYPE, here designated: 1 ♂ USNM 1251667 with mandibles dissected: California, San Diego County, La Jolla, Scripps Institute pier pilings, 6 Nov 1915. USNM Acc. No. 53848, #1045-1-4. Identified as
PARALECTOTYPES: 5 ♂ (USNM 1251667), with mandibles dissected. USNM 53848.
Non-type Material: 1 ♂: Scripps,
Largest ♂ 8.3 mm, largest ♀ 8.7 mm.
No chromatophores: preserved specimen pale buff, whitish.
California, San Diego–La Jolla.
SEMs of
SEMs of
SEMs of
SEMs of
SEMs of
SEM images of
SEM images of epistomes.
We thank the many museum staff who so kindly searched all corners of their collections for Stimpson’s specimens–Marilyn Schotte (USNM), Robert VanSyoc and Elizabeth Kools (CalAcad), Paul Callomon (ANSP), Adam Baldinger (MCZ), Paul Clark (BM), Andres Lopez (UAF), Ardis Johnston (MCZ), Eric Lazo-Wasem and Daniel Drew (PM). Vasily Radashevsky and Marina Malyutina (Institute of Marine Biology, Vladivostok) and Victor Petrjashev (Zoological Museum in St.-Petersburg) are thanked for searching for Kussakin’s specimens from Amchitka. Mark Grygier (Lake Biwa Museum, Japan) is thanked for translating Kussakin from Russian. N. Dean Pentcheff contributed to field collections from Washington to Pt. Fermin, and Todd Haney and Ernie Iverson contributed specimens from San Diego and several other locals. LaiShan Mui is thanked for her whole body drawings funded by NSF Systematics grant DEB-0129317, and Giar-Ann Kung is thanked for her help with the operation of the NHM SEM (funded by DBI-0216506). Gary Poore taught ARW the fine art of electronic inking. Phyllis Sun with her digital expertise helped keep drawing progress moving forward, and Jean Pongsai is thanked for her help preparing the final figures. Our gratitude goes to volunteer par excellence, Jim Cline, for his decade long dedication to isopods, help with sample sorting, and his invaluable contributions to the isopod image gallery (