Dercitus Stoeba bahamensis, Van Soest, Rob W. M., Beglinger, Elly J. & De Voogd, Nicole J., 2010

Van Soest, Rob W. M., Beglinger, Elly J. & De Voogd, Nicole J., 2010, Skeletons in confusion: a review of astrophorid sponges with (dicho-) calthrops as structural megascleres (Porifera, Demospongiae, Astrophorida), ZooKeys 68, pp. 1-88 : 28-29

Dercitus Stoeba bahamensis sp. n. Figs 13 A–E

Dercitus sp.; Kohmoto et al. 1988: 85.

Material examined.

Holotype HBOI 23 –VIII–85–1– 49, (HBOM 003.00040), with schizoholotype fragment ZMA Por. 07782, Bahamas, New Providence Island, NW of Goulding Cay, 25.025°N; 77.583°W, 210 m, coll. K. Rinehart in the Johnson SeaLink submersible, 23 August 1985, don. S.A. Pomponi and M.C. Díaz.

Description.

Slippery smooth encrustation on dead coral (Fig. 13A); the present material (upper part of Fig. 13A) consists of three fragments of 12 × 10, 8 × 8 and 8 × 5 mm, of approx. 1-2 mm in thickness. The holotype (lower part of Fig. 13A) is a larger fragment of 7 × 6 cm (not examined). Colour bright red when alive, darker red in alcohol. Consistency gum-like, easy to cut.

Skeleton: a confused mass of short-shafted triaenes and sanidasters.

Spicules: calthrops-like short-shafted triaenes, dichocalthrops and sanidasters.

Calthrops (Figs 13B, D) showing a clear rhabd, longer than the cladi, which are frequently curved or undulated or bifid. Cladi 138 –166.7– 186 × 12 –22.5– 28 µm, cladomes 207 –266.4– 330 µm in diameter, rhabds 230 –245.9– 270 × 24 –27.2– 30 µm.

Regular symmetrical dichocalthrops (Figs 13 C–D) occur less frequently; protocladi 18 –29.0– 35 µm and deuterocladi 57 –68.1– 105 × 12 –14.1– 18 µm, rhabdomes 70 –141.0– 180 × 12 –20.7– 30 µm, cladomes 143 –197.9– 266 µm.

Sanidasters (Fig. 13E) have an overall short and squat shape. They tend to be amphiaster-like with frequently more heavily spined apices; spines usually with secondary spines. Size 12 –13.3– 15 × 2 –2.85– 3.5 µm.

Etymology.

Named for its type locality.

Habitat.

Collected by submersible at 210 m depth.

Distribution.

Known only from the Bahamian type locality.

Remarks.

This is a Dercitus (Stoeba) species similar to Brazilian Dercitus (Stoeba) latex (Moraes & Muricy, 2007) in shape, colour and consistency. It differs clearly in possessing dichocalthrops and larger unequal-claded calthrops, and the sanidasters are also clearly shaped and sized differently (long and thin with simple spines in Dercitus (Stoeba) latex ). The Bonaire Dercitus (Stoeba) specimen described below differs in being insinuating, lacking dichocalthrops and also having thin sanidasters with undivided rays. Dercitus (Halinastra) lutea (Pulitzer-Finali, 1986, see below) is yellow, lacks dichocalthrops and has compressed sanidasters in its spicule complement. Dercitus (Halinastra) arubensis sp. n. (see below) differs from the new species in lacking dichocalthrops and possessing thick smooth microrhabds.