Xestospongia deweerdtae Lehnert

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 : 91

Xestospongia deweerdtae Lehnert & van Soest, 1999

Synonymy and references. Xestospongia deweerdtae Lehnert & van Soest, 1999: 163, figs. 44–47; van Soest & de Weerdt (2001): 114; figs 4C, D; 5C, D.

Material. USNM 1229139, Carrie Bow Cay forereef cave, 26 m; M. C. Diaz col. 8 Sep 2009.

External morphology. Encrusting, up to 20 mm thick, covering about 90 cm 2 substratum. Irregularly dispersed oscula, most of them elevated on conical protrusions, 3–5 mm diameter. Surface smooth, consistency firm but crumbly. Color, a milky rose red.

Skeleton structure. An unispicular reticulation of strongyles in the ectosome. A similar reticulation in the choanosome, but complemented by multispicular tracts which also form meshes.

Spicules. All are strongyles, most a bit curved, of similar lengths but two classes of thickness; the thinner ones could be considered as earlier growth stages (Lehnert & van Soest, 1999) although juvenile stages were also identified to be oxeote (van Soest & de Weerdt, 2001). Strongyles I: 280–330 x 11–15 (311 x 13) Μm; strongyles II: 270–340 x 3–9 (308 x 6) Μm; strongyles I and II combined: 270–340 x 3–15 (310 x 10) Μm. No oxeote spicules were found in our preparations.

Ecology. So far found on the open, deep forereef to 82 m and in reef caves at 10– 26 m.

Distribution. Caribbean-wide.

Comments. Our specimen entirely covered another sponge, Plakortis angulospiculatus , adhering tightly to the exopinacoderm of the substratum sponge. A similar situation is also described by Zea et al. (2009), who noted that specimens of Xestospongia deweerdtae are “always living over Plakortis halichondrioides .”