Spirastrella coccinea ( Duchassaing & Michelotti, 1864 )

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 : 37

Spirastrella coccinea ( Duchassaing & Michelotti, 1864)

( Figure 20 )

Synonymy and references. Spirastrella coccinea ( Duchassaing & Michelotti, 1864) : Wiedenmayer (1977): 163, fig. 162, pl. 33: 4–7.

Material. USNM 32863, USNM 32868, Columbus Cay, Belize, karst cave wall, 18–21 m; G. Hendler, I. Macintyre, P. Kier, T. Rath, C. Clark col. 26 Apr 1979. USNM 1228953, Carrie Bow Cay, forereef cave, 18 m; K. Ruetzler col. 19 May 1979. USNM 1228954, Carrie Bow Cay, reef flat, under Porites porites and Acropora cervicornis coral rubble, 0.5 m; K. Ruetzler col. 29 Jan 1986. USNM 1228955, Curlew Bank, lower surface of Agaricia coral plate outside caves, 21 m; C. Piantoni col. 28 Jun 2007. USNM 1228956, Curlew Bank, forereef cave, 20 m; C. Piantoni, col. 29 Jun 2007. USNM 1228957, Carrie Bow Cay forereef, cryptic in crevice, 25 m; M. C. Diaz col. 8 Sep 2009. USNM 1228958, Carrie Bow Cay, lagoon patch reef, inside of dead conch shell, 3 m; C. Piantoni, col. 18 Aug 2012. USNM 1228959, 1228960, Curlew Bank forereef slope, small cave, 20 m; C. Piantoni and M. Parrish col. 23 Aug 2012. USNM 1228961, 1228962, Curlew Bank forereef slope, framework cave, 18 m; C. Piantoni and M. Parrish col. 23 Aug 2012.

External morphology. Thin crusts, up to 5 mm, covering areas of 20–50 cm 2. Smooth surface; small oscules (1–3 mm), slightly elevated. Live color bright vermillion to orange red, in some specimens with whitish mottled areas, particularly around the oscules; brownish orange below the ectosome.

Skeleton structure. A layer of spirasters forms a cortex, but the entire cross section of the sponge is almost as dense with these microscleres, obscuring the ascending tracts of tylostyles. This is in contrast with the following species, S. mollis , where microscleres are mainly concentrated in the cortex and near the base, loosely strewn in between.

Spicules. Straight tylostyles with spherical or slightly elongate heads: 146–680 x 5–18 (426 x 11) Μm; spirasters I, axis generally bent twice and with robust spines at either end and on the convex surfaces: 29–61 (46) Μm; spirasters II, smaller versions of spirasters I and many with only one bend: 10–38 (23) Μm.

Ecology. Very common in shaded and dark habitats, lower surfaces of coral rubble and walls and ceilings of caves, 0.5– 21 m.

Distribution. Tropical western Atlantic.

Comments. The brilliant red color of the live sponge, uniform shape of the large and small spirasters (I & II), common occurrence of amphiasters, and simple (not branching) spines distinguish this species from the next, S. mollis .

Figures

FIGURE 20. Spirastrella coccinea, spicules (SEM): a, tylostyles; b, spirasters, with transitions to amphiasters.