Pione vastifica ( Hancock, 1849 )

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 : 31-32

Pione vastifica ( Hancock, 1849)

Synonymy and references. Cliona lampa de Laubenfels, 1950, forma occulta: Rützler (1974): 23, fig. 17d, 20d. Cliona vastifica Hancock, 1849 : Rützler & Stone (1986): 667, fig. 6c, d.

Material. USNM 1228936, Carrie Bow Cay back reef, inside dead conch shell, 1 m; K. Ruetzler & C. Piantoni col. 23 Feb 2006. As foreign spicules in Mycale (Carmia) microsigmatosa . USNM 1228937, Carrie Bow Cay, south back reef, lower surface of platy coral rubble, 1 m; K. Ruetzler col. 17 Aug 2012.

External morphology. A 15 cm 2 area of the internal surface of the conch-shell substratum is punctured by the tiny (0.5 –2 mm diameter) incurrent and oscular papillae of the sponge; the excavated chambers too are small (1 –2 mm) and penetrated 4–6 mm into the substratum. Color of the live sponge is deep red, lighter in the endolithic chambers.

Skeleton structure. Microrhabds are concentrated in the ectosome of the papillae where some tylostyles form brushes. Most tylostyles and microxeas occur in the choanosome, without orientation.

Spicules. Tylostyles, mostly straight and with spherical or ovoid head: 160–340 x 4–7 (289 x 5) Μm; microxeas, slightly bent, tapering to sharp points; microspined: 50– 90 x 3–6 (75 x 4) Μm; microrhabds, strongylote and heavily microspined: 7– 20 x 2–3 (12 x2) Μm.

Ecology. Abundant on shallow reef substrata, 1 m.

Distribution. Throughout the North Atlantic, including the Caribbean, Mediterranean, and Black seas.

Comments. Because of its small papillae, this species is inconspicuous and easily overlooked; even on fully illuminated substrata the papillae are hidden among algal turf. A closely related species (based on spicule morphology), Pione lampa (de Laubenfels), first described from Bermuda (as Cliona ), is encrusting (as well as excavating), bright vermillion in color, and only grows in full sunlight; it has not yet been reported from Belize.