Cerviconia cuspidifera (Lamarck, 1815) Rützler & Hooper, 2000

Rützler, Klaus & Hooper, John N. A., 2000, Two new genera of hadromerid sponges (Porifera, Demospongiae), Zoosystema 22 (2), pp. 337-344 : 342-344

Cerviconia cuspidifera (Lamarck, 1815) n. comb.

Alcyonium cuspidiferum Lamarck, 1815: 168 .

Spirastrella cuspidifera (Lamarck, 1815) . – Topsent 1933: 41.

Spheciospongia cuspidifera (Lamarck, 1815) . – Vicente et al. 1991: 217. – Rützler 1997: 1393. – Wiedenmayer 1977: 117, as Xestospongia tierneyi (Laubenfels, 1953) .

MATERIAL EXAMINED. — Holotype at MNHN labelled “151. Alcyonium cuspidiferum Lmk, LBIM DT 652” and specimens examined by Rützler in Vicente et al. (1991: 217).

TAXONOMIC REMARKS

The type species was recently described and illustrated in detail (Vicente et al. 1991: 217, figs 3c, d, 4; as Spheciospongia ). In summary, Cervicornia cuspidifera forms erect, single or branching staghorn-like hollow cylinders which taper toward the top and are anchored in carbonate sand by a flaring base with root-like extensions. The epibenthic fistules are smooth to the touch, corrugated in places, without macroscopic openings (except for barnacle burrows in some specimens), and measure about 30 × 5 cm; they are cork-like in consistency and walnut brown owing to the presence of unusual zooxanthellae (Rützler 1990). The fistules have an ectosomal histology although a few choanocyte chambers are found here and there. The buried base is tan, incorporates sand and shell particles, is riddled by large canals, and extends deep into the substrate. The base consists primarily of choanosome. Spicular tracts with felted spicules in-between support the walls of the fistules; in the base the spicules are criss-cross, without orientation. Megascleres are tylostyles but modifications include strongyles, styles, and tylostrongyles; percentage-distribution of these types in a specimen varies between geographic regions. Megascleres measure about 330- sponge in the family Placospongiidae . Spicules of the cortical armor, the main distinguishing characteristics, are derived from amphiaster-like spiny rhabds which develop into dumbbell-shaped amphisterrasters. These unusual microscleres are named amphinolasters to set them apart from the monocentric selenasters of the related genus Placospongia and from the euaster-derived sterrasters of the Geodiidae .

The erect branching and partially endopsammic sponge “ Alcyonium ” cuspidiferum Lamarck does not fit into either of the two genera, Spirastrella and Spheciospongia , it was assigned to since the original description. It is now placed into a new genus Cervicornia among massive Clionidae with special inhalant structures. This group has limestone excavating capacity but is without an alpha (chamber-excavating) stage. Cervicornia has staghorn-like, ectosomal inhalant fistules and an endopsammic choanosome. The related Spheciospongia is epibenthic, cake-shaped, and has pore sieves for inhalant specialization.