Corresponding author: Rob van Soest (
Academic editor: R. Pronzato
Among the thousands of non-tetractinellid (monaxonid)
The revision presented below was inspired by the recent discovery of two new species, evidently belonging to the sponge genus
Below, we describe four new species and review previously described species of both genera, pointing out aspects that appear to have been overlooked. We propose the synonymy of several previously accepted species, indicate a serious misinterpretation of the origin of the type species of
Specimens of
Abbreviations of institutions cited in the text:
Terminology: We employ the collective word ‘polyactine’ for the spicules previously named acanthotriaenes by
Microscopic preparation: dissoluted spicule preparations for measurements and SEM observations were made by dissolving a small fragment of the sponge in concentrated HNO3 or in undiluted household bleach, subsequent rinsing at least five times in distilled water, the last time in ethanol 96%, and finally pipetting a spicule suspension on stub or slide to be dried in a stove. Thick sections of the sponge made for the study of the skeletal structure were air-dried on a hotplate or in a stove and embedded in Canada balsam. Measurements of spicules (minimum-
We present the results in the following seven sections: a refined description and illustration of the type material of the type species of
The styles are usually smooth, but in
The species considered valid members of
Summary of taxonomic decisions on
Summary of characters and spicule data of the species of
Genus | Species | Shape | height | Long thin style | Short thin style | short thin style centrotylote | Short thick style | Oxea | Polyactine cladi | Basal cladus | Lateral cladus | Tricho-dragmas |
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
massive | 30 mm | 1700–2200 × 14–22 | 347–490 × 3.5–7 | yes, spined | 361–678 × 15–32 | not present | 3–5 | 54–102 × 9–18 | 39–78 × 7–16 | not present |
|
encrusting | 3 mm | 1058–1643 × 6–12 | 288-456 × 2-4 | no | 204–558 × 9–33 | not present | (1) 3–6 (2) 5–10 | (1)21–51 × 3–10 (2) 18–30 × 1–4 | (1)22–51 × 3–10 (2) 9–24 × 1–3 | not present | |
|
encrusting | 2–3 mm | 1229–1668 × 12–18 | 244–719 × 2.5–9 | no | not present | not present | 4–5 | 51–69 × 5–8 | 31–78 × 4–8 | not present | |
|
|
encrusting | 3–5 mm | 960–2065 × 7–9 | 210–658 × 1.5–4 | no | 174–489 × 7–21 | not present | 3–5 | 32–66 × 3–10 | 30–87 × 4–10 | not present |
|
|
massive | 30 mm | 162–1760 × 9–16 | 302–426 × 1.5–4 | yes | 297–456 × 8–17 | not present | 3–5 | 48–84 × 5–11 | 29–54 × 4–8 | not present |
|
|
encrusting | 1 mm | 900–1400 × 5–7 | not present | no | 150–425 × 10–25 | not present | 3–6 | 35–66 × 5–10 | 35–66 × 5–10 | not present |
|
|
massive | 20 mm | 860–1290 × 6–10 | 191–306 × 1.5–3 | yes, spined | 270–468 × 14–24 | not present | 2–4 | 33–69 × 6–14 | 30–132 × 7–14 | not present |
Cyamon | Cyamonargon | arborescent | 35 mm | 960 × 15 | 210–348 × 3–4 | yes, spined | 350–593 × 15–42 | not present | 2–5 | 33–78 × 6–22 | 30-162 × 5–21 | not present |
|
|
encrusting | not known | 1042 × 41 | 347 | yes? | not present ? | not present | 4 | 76 | 76 | not present |
|
|
encrusting | 3 mm | 129–1989 × 3-33 | 492–698 × 3–5 | no | 129–1989 × 3–33 | not present | 4–5 | 45–93 × 4–11 | 31–51 × 3–7 | not present |
|
encrusting | unknown | 1300 × 30 | 272–355 × 2.5–5 | yes, spined | 421–604 × 16–31 | not present | 3–4 | 104–126 × 11–21 | 42–65 × 10–20 | not present | |
|
|
encrusting | 1 mm | not present | 302–366 × 7–10 | yes | 657–822 × 32–38 | not present | 3–8 | 90–234 × 9–14 | 15–36 × 6–12 | not present |
|
|
arborescent | 200 mm | not present | not present | no | not present | 287–528 × 13–31 | 2–3 | 78–156 × 12–27 | 42–84 × 12 –27 | 57–102 × 4–18 |
|
|
arborescent | 45 mm | 750–1062 × 4–9 | 234–433 × 0.5–2.5 | no | not present | 175–242 × 6–13 | 2–4 | 59–89 × 10–15 | 47–75 × 9–13 | 32–60 × 4–11 |
|
|
flabelliform or arborescent | 60–260 mm | 405–1034 x3–9 | 182–392 × 0.5–4 | no | not present | 135–340 × 5–22 | 2–4 | 96–123 × 10–17 | 51–84 × 9–17 | 35–88 × 6–12 |
|
|
bladed bush | 70 mm | 952–3393 x18–42 | 372–510 × 2.5–3.5 | no | not present | not present | 2–4 | 66–144 × 8–30 | 96–192 × 7–36 | 84–123 × 10–15 |
|
|
flabelliform | 150 mm | 1400–5400 × 8–40 | 130–730 × 3–8 | no | not present | not present | 3–4 | 79–126 × 16–31 | 156–236 × 18–29 | 63–88 × 7–13 |
|
thin branch | 65 mm | 295–1394 × 9–24 | 192–358 × 2–3 | no | not present | not present | 2–3 | 27–96 × 11–21 | 33–121 × 9–19 | 49–61 × 5–11 |
HolotypeBMNH 1877.5.21.1887, dry condition, labeled
The holotype was extensively described by
The specimen consists of a barely coherent mass of columns, fragile, crumbly. Size approx. 3 × 2.5 × 0.6 cm. Colour now dark red-brown.
Skeleton: a branched columnar structure built by bundles of short thick styles supported at the base and along the column by masses of polyactines. The remaining spicules are not readily visible in the sections, so their positions are derived from Carter’s drawings (
Spicules (
Long thin styles (
Short, thin, crooked or wavy, centrotylote styles (
Short thick styles (
Polyactines (2D), robust, mostly equiangular, predominantly four-claded, three-claded forms also rather common, five-claded spicules rare and much smaller than the other; juvenile spicules almost entirely smooth, mature spicules with all cladi spined at the ends, which are also lightly swollen; only sparingly spined near the centre; all cladi approximately equal in length, basal cladi barely distinct from lateral cladi: basal cladi 55–
Contrary to most other authors referring to
(1) There is considerable uncertainty about the origin of the type specimen.
The part of the sentence we placed in roman lettering contains the only factual information on the origin of the specimen, which was subsequently named
(2)
To conclude: specimens identical or similar to the type of
Three samples, ZMA Por. 11729, preserved in alcohol, Seychelles, Amirante Islands, N of Poivre Island,
ZMA Por. 10660, preserved in alcohol, Seychelles, Amirante Islands, NE of D’Arros Island,
ZMA Por. 12558, preserved in alcohol, Seychelles, N of Aride Island,
N.B.: Dendy’s (1922) specimen labeled and described as
Strawberry-shaped sponge (
Skeleton: condition described as columnar, consisting of hillock-like masses of polyactines, variable in thickness up to 2 mm, supporting thick plumose bundles of thick styles, which in turn are peripherally surrounded by short thin strongylostyles. Rare long thin styles are not present in all slides.
Spicules (
Long thin styles (
Strongylostyles (
Short thick styles (
Polyactines (
So far known with certainty from several localities throughout the Seychelles (Mahé and the Amirante Islands).
Sandy bottoms at 30–50 m surrounding reefs and atolls.
The ectosomal strongylostyles in
Encrusting a sandstone flake accompanied by several other encrustations (position of holotype indicated by arrow in
Skeletal structure: A basal mass of polyactine spicules pierced by erect single or bundled thick styles, alternated by long thin styles protruding beyond the surface. At the periphery, the long styles are surrounded by bouquets of thin (tylo-)styles.
Spicules: of five types, long thin styles, short thin styles, short thick styles, large polyactines and small
Long thin styles (
Short thin styles (
Short thick styles (
Large polyactines (
Three-claded forms (rare), basal cladus 36–39 × 8–9 µm, lateral cladi 39–51 × 7–10 µm.
Four-claded forms (most common), basal cladus 18–51 × 3–9 µm, lateral cladi 22–51 × 3–9 µm.
Five-claded forms (also common), basal cladus 21–36 × 6–10 µm, lateral cladi 30–48 × 7–10 µm.
Six-claded forms (rare), basal cladus 21–36 × 4–5 µm, lateral cladi 24–38 × 4–6 µm.
Small
Map showing locality off the Mauritanian coast, where
The name is an adjective that reflects the possession of unique small
(
In shallow-water (12–18 m), highly sedimented environments, in the company of many other sand dwelling sponges such as
The new species stands out among all described
The remaining species appear more distinct with differences in the megascleres (apparent lack of thin styles in
Thin crust, (
Skeleton: columnar bundles of megascleres issuing from a basal layer of polyactines. Columns consist of a single long subtylostyle sheathed in a tight bundle of fusiform centrotylote styles; bundles separate, interconnected only near the substratum.
Spicules of three types: subtylostyles (assumed to be homologues of the long thin styles), centrotylote styles (assumed homologues of the short thin styles), polyactines (short thick styles apparently lacking).
Long thin (subtylo-)styles (
Short thin styles, fusiform, centrotylote (
Polyactines, (
The name is an adjective referring to the type locality: the Mauritanian nature reserve Banc d’Arguin, one of the richest faunal areas of the west coasts of Africa (cf.
(
In shallow-water (12–18 m), highly sedimented environments, in the company of many other sand dwelling sponges such as
The single spined cladus of the polyactine spicules is an alleged feature of the genus
The new species was collected in the same dredge sample as
In view of the proposed major change in the status of
HolotypeMNHN NBE 947, preserved in alcohol, Brazil, NE coast, Calypso stat. 97,
Small hispid crust, color ochre. Detachable skin. The material borrowed from MNHN measured a few mm2 encrusting a small piece of coral.
Skeleton: basal layer of polyactines, upon which megascleres are erected individually.
Spicules: long thin styles, short thick styles, polyactines.
Long thin styles, curved, variable in length, possibly in two size categories, but difficult to establish due to broken condition of most spicules, longest complete spicule 960 × 7 µm (
Short thin styles were not mentioned in
Short thick styles (
Polyactines (
The
ZMA Por. 00828, holotype of
ZMA Por. 10539, preserved in alcohol, Colombia, Santa Marta region, El Morro, 15 m,
USNM 22456, preserved in alcohol, Florida, SE of Loggerhead Key, on a block of limestone dredged from 70 m, coll. M.W. de Laubenfels, 26 June 1932.
USNM 221078 (23563), preserved in alcohol, Florida, Northern Gulf of Mexico, Apalachee Bay, rock and sand, 29.785 –
USNM 33518, preserved in alcohol, off South Carolina, RV
(Based on ZMA Por. 10539). Irregular encrustation (
Skeleton (
Spicules: long thin styles, short thin styles, short thick styles, polyactines.
Long thin styles (
Short thin styles, straight (
Short thick styles, (
Polyactines (
Greater Caribbean, Gulf of Mexico, South Carolina, N.E. Brazil.
Encrusting dead corals and other limestone substrates, 0–70 m.
The loan from the Smithsonian also included an undescribed specimen from South Carolina, USNM 33518. This had long thin styles of up to 2 mm, short thin styles 360–426 × 2–2.5 µm, short thick styles 410–500 × 22–23 µm, and polyactines (three- and four-claded) with basal cladi 48–93 × 12–15 µm and lateral cladi 45–49 × 12–14 µm.
We investigated the type material of
The spicule complement and the shape of the polyactines is broadly similar in the Brazilian type of
Fragment of holotypeSMF 1618, preserved in alcohol, Indonesia, Aru Islands, Straits of Dobo,
The holotype is an encrusting sponge of 6 cm long and 3 cm wide growing over a haplosclerid sponge (Hentschel, 1912). The fragment of less than 0.5 × 0.5 cm and 1 mm in thickness (see
Skeleton: the usual basal mass of polyactinal spicules upon which relatively long styles are erected surrounded in the periphery by bundles of thin centrotylote styles. Thick short styles are singly erect on the substrate, buried in the basal mass of polyactines.
Spicules: long thin styles, centrotylote thin styles, short thick styles, polyactines.
Long thin styles (
Centrotylote thin styles (
Short thick styles (
Polyactines (
Only known from the Arafura Sea.
Deeper water on hard substrate.
The heavy spination of the polyactines appears to be a distinct feature of this species. Hooper’s (1991) redescription denies the occurrence in this species of centrotylote ectosomal thin styles, wheras these spicules appeared common in the fragment of the holotype examined by us. These spicules are comparable to those of
HolotypeUSNM 33630, preserved in alcohol, California, Santa Catalina Island, Big Fisherman’s Cove,
LEB-ICML-UNAM 1497, preserved in alcohol, Mexican Pacific, Islas Marietas (Nayarit), Cueva Marietas,
The holotype (
Thinly encrusting (
Skeleton: a basal mass of polyactine spicules (
Spicules: long thin styles, short thin styles, short thick styles, polyactines.
Long thin styles (
Short thin styles (
Short thick styles (
Polyactines (
Southern California, Pacific coast of Mexico.
Under rocks and in caves in shallow water.
The enhanced bulbous endings of the polyactines is distinctive and is only matched by those of
Holotype USNM 21412, preserved in alcohol, California, between Point Dunes and Newport, near San Pedro.
Shape massively encrusting (
Skeleton: columnar, with thick short styles at the center of a mass of polyactines, with long thin styles protruding from this skeleton surrounded by shorter centrotylote styles.
Spicules: long thin styles, short thin centrotylote styles, short thick styles, polyactines.
Long thin styles (
Short thin styles (
Short thick styles (
Polyactines (
Southern Californian Bight (San Pedro, Santa Catalina island, La Jolla).
On hard substrate, at depths 0–36 m.
Holotype of
Shape upright, bilobed thick branches (
Skeleton: axial-columnar, with surface projections formed by the outwardly directed columns (
Spicules: long thin styles, short thin styles, short thick styles, polyactines.
Long thin styles (
Short thin centrotylote (
Short thick styles (
Polyactines (
Pacific coast of North Mexico.
In kelp forest, 18–27 m.
As pointed out above, this species is close to
With
Seven slides from the collections of the Natural History Museum, BMNH 1954.2.23.8, made of Dendy’s (1905) topotypical material.
Carter’s specimen from the Gulf of Manaar is apparently lost from the collections of the National Museums Liverpool (Dr Ian Wallace,
(Partly from Carter, 1880 and Dendy, 1905). Thinly encrusting, hispid, yellowish brown (alcohol) to cream color (dry). Dendy’s specimen was 1.1 cm in lateral expansion, 3 mm thick. Texture soft.
Skeleton (
Spicules: predominant spicules are longer and shorter subtylostyles with a minority of thin styles and polyactines.
Subtylostyles, presumably a mixture of undifferentiated long thin styles and short thick styles, with prominent heads, usually lightly and gradually curved, in a large size range, which makes determining an average size meaningless: 129–1989 × 3–33 µm.
Thin styles, tapering gradually to thinly pointed curved ends, size range limited, 492–698 × 3–5 µm. Dendy believed these spicules to be growth stages of the subtylostyles, but we regard them, like Carter, as a separate spicule category.
Polyactines [
Only known from the Gulf of Manaar.
Deep water (not specified).
As pointed out above, Mauritanian
None. Type material apparently lost from the collections of the National Museums Liverpool (Dr Ian Wallace,
(From Carter, 1880). Thinly encrusting, hispid, color when dry dark brown. Spicules (
Gulf of Manaar, Southeastern India.
No data.
This species needs redescription, but the long thick styles in combination with the densely spinous polyactines appear sufficiently distinct. Nevertheless there is a resemblance to the polyactines of
partly from
The slide (
Spicules: long thin styles, short thin centrotylote styles, short thick styles, polyactines.
Long thin styles, not frequent, invariably broken, longest fragment measured 1300 × 30 µm.
Short thin styles, wavy outline, faintly centrotylote, under light microscopy mostly looking smooth but occasionally some spines are visible on the pointed end and also in at least one spicule two spines on the rounded end, 272–
Short thick styles, smooth, curved rather strongly near the rounded end: 421–
Polyactines (
The adjective
South India.
No data.
It is with some hesitation that we decided to name this scanty material as a valid new species. Although measurements of the megascleres conform to or are close to those of
Twenty six samples in the ZMA Porifera collection, preserved in alcohol, all from Rockall Bank, approximately
Pale greenish encrustations (
Skeleton: basal mass of polyactines, usually a single layer of spicules, with basal cladi pointing outwards and lateral cladi spread out on the substrate, taking up the position of echinating acanthostyles as in
Spicules: long styles, short styles, polyactines.
Long styles (
Short styles (
Polyactines (
Azores, Ireland, also Norway (P. Cárdenas, pers. comm.). A common North Atlantic bathyal species (
Encrusting deep-sea corals at depths from 500–900 m.
This is a deviating
Polyactine spicules are genuinely polyaxone, with axial canals visible in all of the predominantly three, occasionally four- or two cladi. As will be demonstrated below, none of the specimens of the type species we were able to examine, including the neotype, possess the raspailiid synapomorphy of peripheral long styles surrounded by short styles, despite Hooper’s (2002) description of the type species where such spicules were mentioned. Possibly, but unlikely, these spicules are present in living condition, because we only had dry old specimens available and the peripheral skeleton may have become abraded. It seems likely that Hooper’s (2002) description was based on a contaminated spicule slide. All other
The identity of the sponge named
To conclude: the identity of
A likely candidate is the assumed
The choice of a neotype again is complicated due to a recent discovery in the collections of the Naturalis Biodiversity Center at Leiden (NBC) of four
RMNH Por. 309 (see
The skeleton and spicules of all five specimens conform with the descriptions of
The reason for the names on the labels of the specimens of the NBC and the referral to the Paris Museum is explained in
In view of the uncertain history of the NCB specimens and the more precise data available for the Natural History Museum, London specimen, we here designate BMNH 1872.10.19.1 as the neotype of
It is a pleasure to be able to announce that material of
Neotype (designation herein): BMNH 1872.10.19.1 from Volta River, Fantee, Ghana,
RMNH Por. 306,
RMNH Por. 309,
ZMA Por. 02545, 02546,
BMAG Ah 200.1, 200.3, 2 slides labeled
Wide basal holdfast upon which are erected groups of cylindrical branches, more or less in one plane, each branch usually with one or two dichotomous secondary branches, often also with anastomosing branches. Size of neotype (
Skeleton (
Spicules: Oxeas, polyactines, trichodragmas.
Choanosomal ‘true’ oxeas (
Polyactines (
Trichodragmas (
Tropical West Africa. Type from ‘Elmina, Guinea’ (Pallas, 1766; Esper, 1794), now situated in Ghana. Further specimens were reported mostly from Ghana (neotype (Carter, 1879): Volta; Burton, 1956:
Depth range: no definite data, but probably shallow water, growing on rocks.
The species must have been of common occurrence off the coast of Ghana in 18th century as there are a fair lot of specimens available from that age and region in several natural history museums. Curiously, no fresh material is known to exist, so the species remains ill-known.
Holotype: BMNH 1848.10.4.6 (additional numbers Dh.2, 252), West Africa, coll. Rev. Allen; label text, presumably by Carter, reads
Multi-branched bush (
Skeleton: a comparatively loose reticulation of oxeas echinated sparingly with polyactines, forming rounded or squarish meshes of 150–200 µm diameter, with 5 or more oxeas to the sides, no axial specialization. Peripherally there are numerous long thin styles, accompanied by short thin styles.
Spicules: long thin styles, short thin styles, oxeas, polyactines, trichodragmas.
Long thin styles (
Short thin styles (
Choanosomal ‘true’ oxeas (
Polyactines (
Trichodragmas (
Probably from shallow water or washed up on the beach. No further data.
This is the first redescription after Carter’s report, which is accurate but deficient in omitting the trichodragmas and short thin styles. This is also the first depiction of habit of the specimen and with the details provided here the species is now at least properly described, but it remains ill known.
Holotype missing from SMF, but a paralectotype fragment is present in the Natural History Museum, BMNH 1931.8.4.57, which was examined by JH in 2000, type locality: Indonesia, Aru Islands, 4–15 m depth.
ZMA Por. 02426, preserved in alcohol, Siboga Exped. Stat. 273, Aru Islands, Indonesia, pearl banks off Pulau Jedan,
RMNH Por. 978, preserved in alcohol, Siboga Exped. Stat. 273, same data;
ZMA Por. 14022 and 14023, preserved in alcohol, East Point, Darwin, Northern Territories, Australia, 10 m, 29–11–1987, coll. J.N.A. Hooper nrs 8 and 9;
ZMA Por. 16049, dry old collection material without data.
Two distinct shapes, flabelliform (
Skeleton (
Spicules (
Long thin styles (
Short thin styles (
Choanosomal genuine oxeas (
Polyactines (
Trichodragmas (
Arafura Sea, N and W Australia.
Shallow subtidal to offshore deeper water.
The species was erroneously attributed to
The two ‘growth forms’ are rather distinct, but distribution, skeleton, and spicules are similar and overlapping enitirely, making it impossible to separate the forms further. The digitate form is often overgrown with a zoanthid species, both in Australian (Hooper, 1991) and Indonesian (RMNH Por. 978) specimens. The shape of
The apices of the oxeas and the polyactines show minute spines, which is here interpreted as a unique feature. It violates the rule that in
This is the only
We studied an Indonesian specimen from the ZMA collection labeled
Holotype AHF-NMHLA L-35535 (D33), preserved in alcohol, Hancock Pacific Expeditions, Mexican Pacific, Cedros island, South Bay, approximately
Skeleton: built chiefly by polyactines (no oxeas), supporting the bases of long styles, which are surrounded by dense brushes of short thin styles.
Spicules: long thin styles, short thin styles, polyactines among which numerous diactinal forms, trichodragmas.
Long thin styles (
Short thin styles (
Polyactines (
Trichodragmas (
The holotype was collected in the Southern Californian Bight (Mexican Pacific).
Rocks and reefs at depths of 15–28 m.
The trichodragmas were not cited in the original description.
The specimens described by
Holotype USNM 33631, preserved in alcohol, California, Santa Catalina Island, Bird Rock,
Not examined: paratype BMNH 1985 (reg. nr. unknown), Santa Catalina Island, Ship Rock, on rock at 46 m depth, coll. R. Given.
Flabelliform sponge (
Skeleton (
Spicules: long (thin) styles, short thin styles, polyactines, trichodragmas.
Long (thin) styles (
Short thin styles (
Polyactines (
Trichodragmas: straight, with lightly spined raphides (
Santa Catalina Island, Southern California.
On rocks, from 46–50 m depth.
This species is assigned to
Upright flattened branch with two or three short side projections (
Skeleton: a dense mass of polyactines, towards the periphery surrounding long thin styles and short thin styles, which are embedded in the skeleton more so than in other
Spicules: long thin styles, short thin styles, polyactines, trichodragmas.
Long thin styles (
Short thin styles (
Polyactines (
Trichodragmas (
The name is anadjective referring to the type locality.
République du Congo.
Shallow water
The lack of choanosomal genuine oxeas is shared with Californian
Below the species of
1 | Trichodragmas absent, polyactines are predominantly four-claded or with more cladi, usually shaped equiangular, choanosomal megascleres if present thick styles | ( |
– | Trichodragmas present, polyactines predominantly three-claded Y-shaped, choanosomal megascleres thick oxeas, sometimes absent, but no thick styles | ( |
2 | Thicker and thinners styles both heavily spined on the head and more lightly spined along the shaft , polyactines irregular |
|
– | All styles smooth, polyactines predominantly regular | 3 |
3 | Polyactines in two distinct size categories, the smaller of which is ‘double’ | |
– | No double polyactines | 4 |
4 | Polyactines with only the basal cladi spined or rugose | 5 |
– | Polyactines with all cladi spined or rugose | 6 |
5 | Thin styles fusiform and centrotylote | |
Thin styles not centrotylote |
|
|
6 | Ectosomal short thin styles with rugose or spined pointed end, often also with an angular bend | 7 |
– | Ectosomal thin styles straight, lacking spines or rugose ending or they are entirely absent or not differentiated from long thin styles | 10 |
7 | Diactinal polyactines present (differentiated from true oxeas by a rugose or irregular condition of one of the apices) | 8 |
– | No diactinal polyactines | 9 |
8 | T-shaped three-claded polyactines common, choanosomal styles averaging 30 µm in thickness, shape a little bush |
|
– | Polyactines more regular, choanosomal styles averaging 16 µm in thickness, shape a massive encrustation |
|
9 | Polyactines predominantly three-claded, with a long basal cladus with hook-like spines and shorter only terminally spined lateral cladi | |
– | Polyactines predominantly four-claded, with little distinction in length and spination of all cladi |
|
10 | Ectosomal thin styles have a faint centrotylote condition, polyactine spicules are heavily and entirely spined |
|
– | Ectosomal thin styles present but lacking a centrotylote condition | 11 |
11 | Short thick styles absen |
|
– | Short thick styles present | 12 |
12 | Polyactine spicules have swollen apices, but these are not developed into prominent knobs |
|
– | Polyactine spicules have prominent spined knobs on the lateral cladi |
|
13 | Shape rounded branches | 14 |
– | Shape with flattened blades | 16 |
14 | Styles absent |
|
– | Styles present | 15 |
15 | Choanosomal genuine oxeas present |
|
– | Oxeas absent | |
16 | Choanosomal genuine oxeas present |
|
– | Choanosomal genuine oxeas absent, but diactinal polyactines may be present | 17 |
17 | Shape a single large blade, with dense spicule pelt, styles up to 5.5 mm |
|
– | Shape a bladed bush, hispid, but not with a dense pelt, styles up to 3.5 mm |
|
With the new records from Mauritania, South Carolina and the reassigned Brazil record, the genus
Idealized global distribution of the genus
Species assignable to the genus
Idealized global distribution of the genus
It is likely that more species of both genera will be discovered in the near future.
The two genera were independently erected contemporarily (1867 vs 1870), but at first
Putative similarities and differences of
Character | State |
|
|
---|---|---|---|
Shape | |||
thinly encrusting | √ | – | |
lobate | √ | √ | |
branching | √ | √ | |
flabellate | – | √ | |
hispid surface | √ | √ | |
Architecture | |||
plumose | √ | – | |
reticulate | – | √ | |
raspailiid ectosome | √ | √ | |
Ectosomal styles | |||
long thin styles | √ | √ | |
short thin styles | √ | √ | |
Choanosomal megascleres | |||
thick short styles | √ | – | |
oxeas | – | √ | |
Polyactines | |||
equiangular | √ | √ | |
sagittal | √ | √ | |
all cladi spined | √ | – | |
only basal cladus spined | √ | √ | |
swollen apices | √ | – | |
Trichodragmata | |||
present | – | √ |
Possibly, the position of the polyactines in the skeleton is different in the two genera: usually a basal or central concentration of these spicules in
The isolated occurrence of such unusual polyactine spicules in two genera that are otherwise likely to belong to monactine raspailiids could be interpreted as support for
On the basis of the current state of our knowledge, with, for example, a compelling similarity of polyactines of
Elly J. Beglinger (Naturalis Biodiversity Center, Leiden) made most of the SEM photos. J.A. Cruz (Universidad Nacional Autonoma de Mexico, Estación Mazatlán) assisted with the research on Mexican Pacific species. Kathy Omura (Natural History Museum of Los Angeles County) kindly allowed reproduction of photos made by Phyllis Sun of the types of