Cliona varians ( 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 : 30-31

Cliona varians ( Duchassaing & Michelotti, 1864)

( Figure 15 )

Synonymy and references. Anthosigmella varians ( Duchassaing & Michelotti, 1864) : Wiedenmayer (1977): 165; fig. 165, pl. 35: 1 (forma incrustans).

Material. USNM 1228933, Curlew Bank, forereef slope cave, 20 m; C. Piantoni col. 29 Jun 2007. USNM 1228934, Curlew Bank, forereef slope cave, 20 m; C. Piantoni col. 2 Jul 2007

External morphology. Fleshy crust, 2–5 mm thick, covering 120–500 cm 2 area and excavating and permeating the substratum to a depth of about 8 mm. Due to the porosity of the substratum, excavation chambers are not clearly visible but the few that are range 1–3 mm in diameter. Oscula, 2–4 mm in diameter, are conspicuous, raised on volcano-like elevations and lighter in pigmentation than the rest of the sponge. Color in life is deep greenish brown to light gray, depending on density of symbiotic dinophyceans (zooxanthellae) in the tissue ( Rützler, 1990). The surface of many specimens is densely covered by symbiotic Parazoanthus parasiticus (Duchassaing & Michelotti) (Zoanthidea) .

Skeleton structure. In the choanosome, megascleres are densely interwoven, without orientation; in the ectosome they form brushes toward and beyond the surface.

Spicules. Tylostyles straight or slightly curved, with distinct spherical or ovoid heads: 190 –390 x 10–15 (319 x 13) Μm; “anthosigma”- type spirasters: 10–24 (17) Μm long; rare amphiasters: 10–13 (12) Μm.

Ecology. Coating rock at the bottom of semi-obscure caves, to 20 m.

Distribution. Common off Florida, in the Bahamas, Gulf of Mexico, the Caribbean, and off Brazil. Comments. This sponge is more common and larger in coverage on fully light-exposed, shallow-reef substrata.

Figures

FIGURE 15. Cliona varians, spicules (SEM): a, tylostyles; b, spirasters and one amphiaster.