Raspailia (Parasyringella) thamnopilosa, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 62-63

Raspailia (Parasyringella) thamnopilosa sp. nov.

Figures 40 a–d

Material examined. Holotype RMNH Por. 6301, Suriname, ‘ Luymes O.C.P.S. ’ Guyana Shelf Expedition, station K101B, 7.3783°N 54.3583°W, depth 93 m, rectangular dredge, 17 April 1969 .

Paratype RMNH Por. 10550, same data as holotype.

Description. ( Fig. 40 a) Small arborescent hairy sponges (two almost identical specimens), with short stubby branches partially anastomosed. Size about 2 cm high, 1.5 cm wide, individual branches 2–4 mm in diameter. Color in alcohol light beige. Consistency firm, slightly compressible.

Skeleton. Densely spiculous, with a central axis of styles, curved oxeas and rhabdostyles in a vague reticulation, without visible spongin. From the axis long styles verge toward the surface and protrude far beyond it causing hispidity and a hairy aspect.

Spicules. ( Figs 40 b–d) Styles, oxeas, rhabdostyles.

Styles ( Figs 40 b,b1) of the central column and surface, usually curved, occasionally more or less straight, slightly fusiform, with the rounded head marginally thinner than the middle part of the shaft, 612– 923 – 1092 x 18 – 23.2 –28 µm.

Oxeas ( Figs 40 c,c1), strongly curved, often a bit crooked with abrupt bends, but never sinuous, occasionally one of the apices is bluntly rounded, but the majority are sharply pointed, in a large size range, 217– 336 –464 x 8 – 11.3 –14 µm.

Rhabdostyles ( Figs 40 d,d1) smooth, short and fat, with abrupt curve just below the rounded head, in a large size range, 177– 326 –509 x 11 – 18.2 –26 µm.

Distribution and ecology. Guyana Shelf, on sandy bottom at 93 m depth.

Etymology. Thamnos (Gr.) = bush, pilosus (L.) = hairy, referring to the shape of the sponge.

Remarks. None of the described Central West Atlantic sponges appear to be similar to the above-described specimen. It is difficult to assign to any genus with certainty. On overall spiculation it could conform to Axinella , a genus, which has been demonstrated on molecular grounds to be polyphyletic. However, the spined surface and the axial skeleton of strongly curved oxeas and rhabdostyles of the present specimen do not resemble that of any of the described Western Atlantic Axinella species (cf. Alvarez et al. 1998). The spined surface caused by protruding long styles reminds of Raspailia , but its lack of acanthostyles and lack of typical raspailiid bouquets of thinner shorter spicules (either styles or oxeas) makes membership of that genus less likely. The subgenus Raspailia (Parasyringella) unites Raspailia species lacking acanthostyles, and with some hesitation I assign the present specimens to that group.

Raspailia (Raspaxilla) bouryesnaultae Lerner et al., 2006 (replacement name for R. (R.) elegans sensu Boury- Esnault, 1973) from NE Brazil also has rhabdostyles, but these are spined, unlike the entirely smooth rhabdostyles of the new species.

Figures

FIGURE 40. Raspailia (Parasyringella) thamnopilosa sp. nov., a, habitus of holotype RMNH Por. 6301 (scale bar = 1 cm), b – d, SEM images of spicules, b, style, b 1, details of b, c, oxea, c 1, details of c, d, rhabdostyle, d 1, details of d.