Timea oxyasterina, Rützler, Klaus, Piantoni, Carla, Van, Rob W. M. & Díaz, Cristina, 2014

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 : 48-49

Timea oxyasterina new species

( Figures 3 f, 26)

Material. Holotype: USNM 1228987, Curlew Bank forereef cave, 20 m; C. Piantoni col. 28 Jun 2007. Diagnosis. Timea with one kind of oxyasters as only microscleres (center <1/3 of total diameter), with slim, smooth rays, microspined only along the distal half of their lengths.

External morphology. The holotype is a 1–4 mm thick crust extending over nearly 10 cm 2, part of a much larger specimen. The surface is smooth but rugose and shows numerous circular aquiferous openings of 0.2–0.8 mm diameter. Consistency firm, compressible, live color deep red.

Skeleton structure. Tylostyle brushes and single spicules extend from the base layer of microscleres to the ectosome, points outward, some protruding from the surface. Only few of the oxyastrose microscleres occur in the ectosome but instead are crowded at the base of the crust and are densely populating tissue that fills, and possibly excavates, small cavities in the substratum.

Spicules. Tylostyles in one size class but of large range in length, straight or gently bent, with heads that may be barely thicker than the shaft, missing in some (styloid modifications), or is subterminal (mucronate) in a few: 152–320 x 3–11 (232 x 6) Μm; oxyasters (center diameters: 21–31 % of total diameters), with slim, cylindrical rays and rounded point, smooth around the center, microspined along the distal half: 25–37 (32) µm.

Ecology. Found on the wall of a forereef cave, closely associated with the astrosclerid (“sclerosponge”) Goreauiella auriculata , whose base skeleton it at least partly overgrows; 20 m.

Distribution. Belize.

Etymology. Named for the simple oxyasterine microscleres.

Comments. This is the second known central West Atlantic Timea with just one type and size category of euaster, the other is T. unistellata sensu Pulitzer-Finali (1986; see description there) . In short, the principal difference is that T. unistellata has small (14 µm, in our material) spheroxyasters with conical, microspined rays, T. oxyasterina has larger (32 µm) oxyasters with cylindrical, microspined rays.

Figures

FIGURE 3. In-situ photographs of new sponge species reported in this contribution (measurements in parentheses are picture widths): a, Tetralophophora mesoamericana (3 cm); b, Geodia cribrata (12 cm); c, Placospongia caribica on “ pseudostalactite ” made up by calcareous serpulid tubes (5 cm); d, Prosuberites carriebowensis (adjacent to Monanchora arbuscula to the lower right) (4 cm); e, Timea diplasterina (8 cm); f, Timea oxyasterina (4 cm); g, Rhaphidhistia belizensis (14 cm).