Sponges of the Guyana Shelf
Van, Rob W. M.
Zootaxa
2017
1
1
225
[151,426,1831,1857]
Demospongiae
Hemiasterellidae
Hemiasterella
Animalia
Hadromerida
173
174
Porifera
species
camelus
sp. nov.
Material examined. Holotype RMNHPor. 9924, Suriname, ‘ Luymes O.C.P.S.II’ GuyanaShelf Expedition, station M97, 7.3083°N 54.1667°W, depth 130 m, bottom coarse sand, 16 April 1969.
Description.The holotype( Fig. 109a) is bilobate, pale orange-brown in alcohol, with a punctate micronulose surface. Lobes crowned by apical oscules, which appear irregularly compound with several smaller and larger partially connected openings, likely caused by collapse of wider openings. Maximum height of specimen 7 cm, maximum width 6 cm, lobes 4–5 cmdiameter at the base, approximately 2 cmdiameter at the top. Consistency firm, rather incompressible. Skeleton.At the surface there is a thick cover of aster microscleres carried by loose bundles of both smaller and larger oxeas, which push up the surface into low blunt conules. Inbetween these conules there is a network of inhalant openings 0.2–0.4 mmin size. The skeleton of the choanosome is largely confused, consisting of individual larger oxeas strewn without obvious direction, and crowded asters. Smaller asters rare, found in dissoluted spicule mounts, but not readily detected in a thick sections. Spicules.( Figs 109b–e) Oxeas, oxyspherasters. Oxeas, straight, fusiform, sharply pointed, occasionally with stylote heads, in two size categories, (1) large and thick ( Figs 109b,b1), 1740– 2006– 2220 x 27– 49.6–58 µm, and (2) small and thin ( Figs 109c,c1), 597– 798–963 x 9– 17.4–24 µm. Oxyspherasters, smooth, with sharply pointed conical rays, in two size categories, (1) larger ( Figs 109d), 35– 61–78 µm, ray number 6– 11.8–16, and (2) smaller ( Figs 109e), 7– 13.8–18 µm, ray number 10– 11.4–12.
Distribution and ecology. GuyanaShelf, on sandy bottom at 130 m.
Etymology. Camelus(L.) = camel, referring to the shape of the holotyperesembling a camel’s two humps.
Remarks.The only other Central WestAtlantic Hemiasterellais H. ajax( De Laubenfels, 1950)(originally Epallax ajax) from an inland mangrove pond in Bermuda. A paratype, BMNH1948.8.6.49, was examined. Itshows considerable similarity to the new species: it is a globular mass with large fusiform oxeas as megascleres and two distinct size categories of oxy(spher)asters as microscleres. Thereare also compelling differences between the two species. The Bermudaspecimen is white (in life as well as in alcohol), the larger oxeas are thinner and longer (1500–3300 x 15–32µm), there are no small oxeas in the size range below 1000 µm, and the larger oxyasters are not oxyspherasters and all have a small number of rays (usually 3–4). Furthermore, the Bermudaspecies is only known from a shallow water inland pond, quite the opposite of the new species, which was taken at 130 mdepth. Some resemblance is also apparent with the recently described Jaspis atolensis Lira & Pinheiro, 2015from the Atol das Rocas in NE Brazil(depth given as ‘loose above the reef’, thus probably from shallow-water). The shape is dissimilar, but irregularly massive, so not too distinct from H. camelus sp. nov.Its skeleton and spicule complement is not unlike the above-described specimen, but the larger oxeas are only up to 1400 x 13µm (against up to 2220 x 58in H. camelus sp. nov.). In view of this and the different depth occurrence, it is likely a related but different species. Assignment to Jaspis Gray, 1867appears unjustified as the smaller oxeas are not arranged tangentially as in the typespecies, J. johnstonii( Schmidt, 1862). Lira & Pinheiro’s (2015) redescription of the typespecimen of Schmidt rather contrasts with those of earlier authors ( Topsent 1900as Coppatias johnstonii,and Uriz 2002) by its emphasis on an ‘undifferentiated’ ectosome. This probably relates to the quality of the dry typematerial rather than to the true properties of Jaspis johnstonii, which does have an ectosomal tangential or paratangential crust of the smaller oxeas. Jaspis atolensisfits probably better in Hemiasterella.
1424726564
1969-04-16
RMNH
Luymes O. C. P. S.
Suriname
130
7.3083
Suriname
7
-54.1667
173
174
1
holotype
1424726537
Bermuda
Central West
175
176
1
Central West
1424726554
1932-10-15
BMNH
Bermuda
Furthermore
130
It
There
175
176
BMNH 1948.8
1
paratype