Topsentia ophiraphidites De Laubenfels 1934

Topsentia ophiraphidites (De Laubenfels, 1934)

Figures 117 a–e

Restricted synonymy: Ƒiles ophiraphidites De Laubenfels, 1934: 13.

Topsentia ophiraphidites; Díaz et al. 1993: 290, figs 6, 12 (with further synonyms and records).

Material examined. RMNH Por. 9303, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station G56, 7.26°N 56.6667°W, depth 67–68 m, Agassiz trawl, 10 May 1966; RMNH Por. 9771, 9827, Suriname, ‘Luymes’ Guyana Shelf Expedition, station 1, 7.1667°N 53.5833°W, depth 104–130 m, bottom sandy calcarenite, 24 August 1970.

Description. Fistular fragments (Fig. 117 a), which presumably represent the tops of larger masses that remained uncollected, and one small globular sponge with cut-off projection (Fig. 117 a1). The fragments are up to 6.5 cm high, 2–4 cm at their base, 1 cm at their apices, the globular sponge is 4.5 cm diameter and high, with the projection 1.5 cm in diameter. The sponge samples are rather divergent in shape, but spiculation is identical. Color (in alcohol) pale yellowish beige to dark brown. Consistency firm, rough to the touch.

Skeleton. Largely confused mass of spicules, with vague tracts of the larger spicules running perpendicularly to the surface. Smaller spicules are more frequent at the surface.

Spicules. (Figs 117 b–e) Oxeas only.

Oxeas, usually straight or slightly curved, intermediate and smaller oxeas occasionally angularly curved or crooked, in a wide range of shapes and sizes, divisible in overlapping size ranges, (1) large and fat (Figs 117 b,b1), fusiform, 1050–1348 x 34 –63 µm, (2) intermediate (Figs 117 c,c1), with gradually tapering sharp points, some crooked forms occur, 546–858 x 16–26 µm, and (3) small (Fig. 117 d), likewise with sharp points, including a few crooked forms (Fig. 117 e), 295–452 x 7–10 µm; overall oxea size 295– 837 – 1348 x 7 – 28.7 –63 µm.

Distribution and ecology. Guyana Shelf, Greater Caribbean, NE Brazil, in a wide depth range, 1–130 m (Guyana Shelf 67–130 m).

Remarks. The identification is made on the basis of the key to the Central West Atlantic species of Topsentia and description in Díaz et al. (1993). The present material matches their treatment of T. ophiraphidites closely in spiculation and skeletal structure. Specimens of T. ophiraphidites are known to possess fistular outgrowths and are diverse in size and shape. The depth range of the species, previously known down to 55 m, is extended here considerably down to 130 m.

Two other recognizably described species are present in the region, T. bahamensis Díaz, Pomponi & Van Soest, 1993, which is shaped differently and its spicules do not exceed 800 µm in length, and T. pseudoporrecta Díaz, Pomponi & Van Soest, 1993, which has coarser texture and spicules up to 1800 µm in length.

The WPD lists Pellina profunditatis Schmidt, 1870 from 532 m off Florida as a Topsentia. The encrusting sponge apparently had a skeleton of oxeas of very variable size, the thickness given as 6–77 µm. This is insufficient to characterize the species. Type material consists of a slide in the BMNH collection, 1870.5.3.102 (source Desqueyroux-Faúndez & Stone, 1992, p. 54) and a 70% alcohol specimen in the MCZ collection, reg.nr. PORb- 122. Neither was recently redescribed.

Gammill (1997) uses Topsentia amorpha as a name for a sponge from the Bahamas. He ignored the rules of the ICZN by not indicating and keeping type material and his description is unrecognizable. The name is a clear nomen nudum and through that is unavailable.