Acanthella vaceleti Van Soest & Stentoft, 1988

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 65

Acanthella vaceleti Van Soest & Stentoft, 1988

Figures 42 a–f

Acanthella vaceleti Van Soest & Stentoft, 1988: 107 , fig. 53; Alvarez et al. 1998: 37, fig. 1.

Material examined. RMNH Por. 9779, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station B23B, 7.297°N 55.3883°W, depth 99–101 m, rectangular dredge, 27 April 1966 ; RMNH Por. 9791, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 51, 7.6833°N 57.0333°W, depth 98 m, bottom calcareous sand, 30 August 1970 ; RMNH Por. 10536, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station E66, 7.1°N 56.1783°W, depth 65 m, Agassiz trawl, 13 May 1966 .

Description. ( Fig. 42 a) Erect, irregularly bladed growth forms, without stalk. Dimensions of largest specimen 5 x 5 x 5 cm, blades 3–5 mm thick. Surface indented with lengthwise grooves. Color (in alcohol) pale beige or brown. Consistency firm but elastic.

Skeleton. Of the blades and outgrowths consisting of a thick central axis ( Fig. 42 b), 1–1.3 mm diameter, of intertwined sinuous strongyles. Extra-axial skeleton consists of outgrowths of the central axis with a mixture of styles and strongyles and many single styles.

Spicules. ( Figs 42 c–f) Styles, ‘sinuous’ strongyles.

Styles ( Figs 42 c–d) smooth, usually curved, with rounded end often slightly narrower than the shaft, but not distinctly fusiform, in a large size range of shorter-thicker ( Figs 42 c,c1) and longer-thinner spicules ( Fig. 42 d), but not divisible into clear size categories, 246– 610 – 1152 x 6 – 17.1 –39 µm.

Sinuous strongyles, smooth, doubly or multiply curved, in a large size range, 481– 1041 – 1440 x 9 – 11.4 –14 µm.

Distribution and ecology. Guyana Shelf, Barbados, Gulf of Mexico, 65–108 m depth ( Guyana Shelf 65–101 m).

Remarks. The specimens are somewhat more bladed and arborescent than the holotype, but other features (skeletal structure and spicule types and sizes) match. Spicules of our specimen have a somewhat wider range than those of the type. The Gulf of Mexico specimens ( Alvarez et al. 1998) have spicule data similar to the above, and the shape is even more ‘bladed’ than the present specimens. Other Central West Atlantic Acanthella specimens have clearly different habitus [erect, tree-like A. mastophora ( Schmidt, 1870) and A. flagellifera ( Van Soest & Stentoft, 1988) and massive-lobate A. cubensis ( Alcolado, 1984) ].

Figures

FIGURE 42. Acanthella vaceleti Van Soest & Stentoft, 1988, a, habitus of RMNH Por. 10536 (scale bar = 1 cm), b, SEM image of a portion of the axial column, c – f, SEM images of spicules, c, shorter thicker style, c 1, details of c, d, longer thinner style, e, shorter sinuous strongyle, e 1, details of e, f, longer sinuous strongyle.