Myrmekioderma rea

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 : 72-74

Myrmekioderma rea (de Laubenfels, 1934)

Synonymy and references. Myrmekioderma styx (de Laubenfels, 1934): Diaz et al. (1993): 303, figs. 38, 44.

Material. USNM 1229078, Carrie Bow Cay forereef cave, 18 m. K. Ruetzler col. 19 May 1979. USNM 1229079, Curlew Bank forereef cave, 20 m; C. Piantoni col. 2 Jul 2007. USNM 1229080, Curlew Bank forereef cave, 18 m; C. Piantoni and M. Parrish col. 22 Aug 2012.

External morphology. Cushion-shaped to irregularly massive, with surface structured by meandering ridges and grooves, with oscula elevated on lobes. Specimens up to 11 x 5 x 4 cm, oscula 1–3 mm in diameter. Consistency firm but easily crumbled; mucous when squeezed. Color yellow to orange red.

Skeleton structure. In the ectosome, small spicules (acanthoxeas) are oriented in paratangental to perpendicular fashion forming a crust. In the choanosome, large spicules (oxeas) occur without orientation, in criss-cross fashion with small ones mixed in, some form vague tracts leading toward the surface.

Spicules. Large oxeas smooth, gently bent, thickest in the center and gradually tapering to sharp points; a few are double bent (in the same direction) and there are some styloid and strongylote modifications: 680–1000 x 18–34 (673 x 27) Μm; acanthoxeas (microspined), more or less gently bent, sharply pointed at the ends, with surface covered irregularly with minute spines (0.5–1 µm): 226–410 x 8–15 (327 x 11) Μm; raphids (bundled in trichodragmas) very thin and easily overlooked, 110 x <1 µm.

Ecology. In forereef caves, 18–20 m; reported from deep reefs to 100 m.

Distribution. From Florida to the Gulf of Mexico and throughout the Caribbean.