Petrosia (Petrosia)

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 : 90-91

Petrosia (Petrosia) sp.

Synonymy and references. Petrosia (Petrosia) Vosmaer, 1885 : Desqueyroux-Faúndez & Valentine (2002): 911, 912, fig. 3.

Material. USNM 1229137, Carrie Bow Cay, back reef, inside dead conch shell, 1 m. K. Ruetzler and C. Piantoni col. 23 Feb. 2006.

External morphology. Thin, uneven cushions, 40–50 x 20–35 mm, up to 5 mm thick, with a few 1–2 mm oscula. Rough surface, firm but fragile consistency. Color white, in life as well as preserved in alcohol.

Skeleton structure. In the ectosome, oxeas are in tangential position, the large ones forming a vague network, but mainly criss-cross, with small ones laying interstitially. In the choanosome, the oxeas are in multispicular reticulation.

Spicules. Gently curved, acerate oxeas of two size classes, a few of the larger ones with one or two sharp kinks. Oxeas I: 330–410 x 11–18 (374 x 16) Μm; oxeas II: 130–280 x 7–10 (150 x 9) Μm. Ecology. Our specimen was found cryptic inside a dead conch shell discarded in the back reef, 1 m. Distribution. Carrie Bow Cay, Belize.

Comments. Our material does not resemble any described species but is too small to justify establishing a new species. Based on skeleton structure and oxeas as spicules, the species resembles Petrosia (Petrosia) weinbergi , but it differs in color (white instead of brown) and larger and more pointed oxeas without styloid and strongyloid modifications.