Xestospongia rampa

Rützler, Klaus, Piantoni, Carla, Van, Rob W. M. & Díaz, Cristina, 2014, Diversity of sponges (Porifera) from cryptic habitats on the Belize barrier reef near Carrie Bow Cay, Zootaxa 3805 (1), pp. 1-129 : 93

Xestospongia rampa (de Laubenfels, 1934)

Synonymy and references. Strongylophora rampa de Laubenfels, 1934: 19; Xestospongia rampa (de Laubenfels, 1934): van Soest et al. (2013b).

Material. USNM 1229142, Carrie Bow Cay, back reef near crest, 0.3 m; inside and underside of Acroporal palmata coral rubble. K. Ruetzler col. 23 Apr 1974.

Other material studied: holotype USNM 22386 from Puerto Rico.

External morphology. A low cushion (22 x 15 mm, 4 mm thick) bearing two slightly raised oscula (1–2 mm diameter). Smooth surface, spongy but fragile consistency; color gray.

Skeleton structure. The thinner spicules (oxeas), are in tangential position in the ectosome, some are connected to form an unispicular network. In the choanosome, strongyles form a multispicular mesh, with a few poorly defined tracts and numerous loose strongyles and oxeas in between.

Spicules. The principal spicules are strongyles, some grading into blunt-pointed styles and oxeas; all are somewhat bent: 270–345 x 10–19 (310 x 16) Μm; in addition there are slender oxeas: 270–345 x 10–19 (310 x 16) Μm.

Ecology. Our specimen was found cryptic under shallow reef rubble. The type material from Puerto Rico was dredged from 68– 216 m.

Distribution. Belize and Puerto Rico; presumably Caribbean-wide.

Comments. The type material was described as irregular to cylindrical; ours is obviously a young, encrusting specimen. The spicules agree morphologically well with the type, except that the strongyles are slightly shorter and thicker (holotype: 360 x 13 Μm). The oxeas are of the same dimension.