Sponges of the Guyana Shelf Author Van, Rob W. M. text Zootaxa 2017 1 1 225 journal article 10.5281/zenodo.272951 e2c88f4c-3ac2-45f9-95e4-99b75561a081 1175-5326 272951 6D68A019-6F63-4AA4-A8B3-92D351F1F69B Characella poecillastroides Van Soest, Meesters & Becking, 2014 Figures 62 a–g Characella poecillastroides Van Soest et al. , 2014: 410 , figs 6a–d, 7a–e. Material examined. RMNH Por. 9822, Suriname , ‘Luymes’ Guyana Shelf Expedition, station 1, 7.1667°N 53.5833°W , depth 104–130 m , bottom sandy calcarenite, 24 August 1970 . Description. Two fragments of a flattened sponge ( Fig. 62 a), overall size 11 x 7 x 2 cm. Surface smooth where not overgrown by a other sponges, but rough and hard in exposed places. Color in alcohol yellowish beige. Skeleton. Ectosomal skeleton with a crust of acanthomicroxeas, carried by bundles of long oxeas and confusedly arranged plagiotriaenes. Choanosome with confused mass of spicules. The surface bears a crust of Parahigginsia cf. strongylifera (see above). Spicules. ( Figs 62 b–g) Oxeas, plagiotriaenes, amphiasters, acanthomicroxeas. Oxeas ( Figs 62 b,b1) fusiform, curved, rather abruptly pointed, quite variable in length, 1350– 1943 –2450 x 34 – 55.2 –71 µm. Plagiotriaenes ( Fig. 62 c), short-shafted, but usually the rhabd and the cladi are distinct, rhabdomes 294– 397 –520 x 24 – 29.5 –36 µm, cladomes 288– 334 –390 µm, cladi 126– 185 –234 x 23 – 26.2 –30 µm, Amphiasters ( Fig. 62 d), with relatively robust and finely spined rays, overall diameter 16– 18.2 –21 µm. Acanthomicroxeas ( Figs 62 e–g), in two to three size categories, (1) larger ( Figs 62 e,e1) 210–256–282 x 5 – 6.0 –6.5 µm, (2) intermediate ( Fig. 62 f), rare (n=4) 76–172 x 2–3 µm and (3) small ( Fig. 62 g) 34– 43 – 51 x 2.5– 3.1 –3.5 µm. FIGURE 62. Characella poecillastroides Van Soest, Meesters & Becking, 2014 , a, habitus of RMNH Por. 9822 (scale bar = 1 cm), b–g, SEM images of spicules, b, oxea, b1, details of b, c, plagiotriaene, d, amphiaster, e, large acanthomicroxea, e1, details of e, f, intermediate acanthomicroxea, g, small acanthomicroxea. Distribution and ecology. Guyana Shelf, Bonaire , sandy and rocky bottoms at 104–168 m depth. Remarks. The fragments reported here are closely similar in habit and spicules to the type . The plagiotriaenes are slightly smaller and there is a rare middle-sized acanthomicroxea (70–170 µm), which is not reported from the type . The surface is encrusted by what appears to be a Parahigginsia rather similar to what was recently described as P. strongylifera , because of the possession of the characteristic acanthomicroxeas with thin erect spines. See above for a description and discussion. Remarkably, instead of strongyles, the spicules are thickly fusiform oxeas arranged in a confused reticulation. These spicules are also shorter, 171–204 x 9–14 µm than the strongyles of the type (290–370 x 10–18 µm). It remains to be decided whether the present encrustation falls within the variation of P. strongylifera . Puerto Rican Characella enae ( De Laubenfels, 1934 ) (as Neothenea , p. 5), ( type specimen USNM 22321, slide re-examined), shows a general similarity to C. poecillastroides . It has a flabellate shape, but its megascleres are consistently much longer and thicker than those of C. poecillastroides : oxeas up to 12 mm x 106 µm, plagiotriaenes and dichotriaenes (not found in C. poecillastroides ) with cladi similarly up to 100 µm in thickness, amphiasters are 25–30 µm and acanthomicroxeas show less differentiation in size categories.