Aplysina fistularis ( Pallas, 1766 )

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 : 97

Aplysina fistularis ( Pallas, 1766)

Synonymy and references. Aplysina fistularis ( Pallas, 1766) forma fistularis: Wiedenmayer (1977): 64 , pl. 5 fig. 3 (including synonymy).

Material. USNM 1191349, Curlew Bank forereef slope (wall), framework cave, 20 m; C. Piantoni col. 28 Jun 2007.

External morphology. The specimen is cushion-shaped, measuring 20 x 15 mm, 15 mm thick. There is one principal osculum on top, 2.5 mm in diameter, a few smaller ones dispersed over the body. The surface is conulose, with some conules connected by ridges. The consistency is spongy but firm, the color yellow to brown, turning to greenish upon exposure to air and, finally (after fixation), to dark purple.

Skeleton. The amber, striated and pithed skeleton fibers form contorted meshes, 0.6–2.2 mm in diameter. Their diameters have a large range: 30–150 (88) Μm; the pith occupies about 40 % of that, on average.

Ecology. A common sponge of the forereef, its distribution spreads occasionally into shaded habitats. under a coral slab and inside the entrance of a small reef crevice under semi-obscure conditions; 3– 20 m.

Distribution. From Bermuda throughout the Caribbean to Brazil.

Comments. Typical specimens of this species develop thick-walled chimneys but those were not found in the caves. But the cushions observed by us have the same surface structure, consistency, color (including aerophobic change), and skeleton properties and are therefore considered conspecific.