Cladocroce guyanensis, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 26-27

Cladocroce guyanensis sp. nov.

Figures 15 a–c

Material examined. Holotype RMNH Por. 9826, Suriname, ‘Luymes’ Guyana Shelf Expedition, station 1, 7.1667°N 53.5833°W, depth 104–130 m, bottom sandy calcarenite, 24 August 1970 .

Description. Flabelliform sponge, torn up during collection into half a dozen larger and smaller thin-bladed fragments ( Fig. 15 a), largest of which is 6 x 2.5 cm in lateral size, 1–3 mm in diameter. Assuming all fragments belong to a single specimen, then overall size is estimated to be at least 10 x 8 cm. One of the fragments is ridged on one side, presumably representing part of the holdfast. Color (in alcohol) pale orange-brown. Surface smooth, punctate, not clearly different in aspect on either side. Consistency corky, but fragile.

Skeleton. ( Fig. 15 b) Largely unispicular, but irregular, with some nodal spongin, but otherwise devoid of visible spongin. Next to this reticulation, there are several subectosomal longitudinal spicule tracts, 80–120 µm in thickness, made up of 4–6 spicules. These tracts run lengthwise through the bladed sponge body, but are never pronounced and do not continue for very long distances.

Spicules. Oxeas only.

Oxeas ( Fig. 15 c), slightly curved, slightly fusiform, occasional stylote forms, 336– 383 –414 x 9 – 15.8 –19 µm.

Distribution and ecology. Guyana Shelf, sandy bottom at 104–130 m depth.

Etymology. Named after the Guyana Shelf.

Remarks. No chalinid species with this habitus and spiculation has been reported from the Western Atlantic. The species is assigned with some hesitation to the genus Cladocroce , based on its flabelliform habitus, presence of longitudinal tracts and a unispicular reticulation. Over the years, the contents of Cladocroce has been widened from exclusively deep-water / cold-water, basically flabelliform or vasiform sponges to include tubular shallow-water / warm-water forms such as Cladocroce aculeata Pulitzer-Finali, 1982 and C. burupha Putchakarn, De Weerdt, Sonchaeng & Van Soest, 2004 . Assignment of the present cold-water species to Cladocroce is based on the typical thin-bladed forms. The longitudinal tracts of the present species are not very pronounced and as such also occur in some Haliclona species. Revision of Cladocroce is urgent.

Figures

FIGURE 15. Cladocroce guyanensis sp. nov., a, habitus of fragmented holotype RMNH Por. 9826 (scale bar = 1 cm), b, light microscopic image of surface skeleton, c, SEM images of oxeas.