Mycale (Mycale) laevis ( Carter, 1882 )

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 : 69

Mycale (Mycale) laevis ( Carter, 1882)

Synonymy and References. Mycale (Mycale) laevis ( Carter, 1882) : van Soest (1984a): 14, fig. 2, pl. 1, 1–4; Hajdu & Rützler (1998): 763, figs. 14, 15.

Material. USNM 1229068, Carrie Bow South back reef, lower surface of rock slab; 1 m; K. Ruetzler col. 13 Mar 0 9.

External morphology. A crust covering 35 cm 2, 3 mm thick. Surface rough to the touch, with scattered and slightly elevated 2 mm oscula. Color greenish yellow.

Skeleton structure. In the ectosome, megascleres occur more or less tangentially with microscleres in between. In the choanosome, most megascleres form dendritic tracts, along with many loose spicules that occur without orientation.

Spicules. Slim subtylostyles, with elongate oval heads, more or less sharply pointed: 379–530 x 8–15 (495 x12) Μm; anisocheles I: 45–56 (51) Μm; anisocheles II, with foot reduced to a hook and a downward spur: 12–15 (14) Μm; sigma I: 36–40 (38) Μm; sigma II: 14–17 (16) Μm; raphids in two size classes, all about 0.8 µm or less thick and bundled as trichodragmas, I: 44–80 (66) Μm; raphids II: 19–24 (21) Μm.

Ecology. The described specimen was cryptic under coral rubble on the shallow reef, but the species is more commonly observed at the base of forereef corals, also on mangrove stilt roots in well-flushed mangrove channels, 1– 25 m.

Distribution. Caribbean, including the Gulf of Mexico.

Comments. Spicule dimensions are small compared to previously described material. This is considered a young specimen of this common forereef species.