Thrinacophora funiformis Ridley & Dendy, 1886

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 64-65

Thrinacophora funiformis Ridley & Dendy, 1886

Figures 41 a–e

Thrinacophora funiformis Ridley & Dendy, 1886: 484 ; Ridley & Dendy 1887: 195, pl. XIII fig. 1, pl. XXIV fig. 1; Hooper 2002a: 494, fig. 14 (redescription of holotype); Muricy et al. 2011: 150 (with further Brazilan records).

Material examined. RMNH Por. 9312, 9810, 9847, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station I121, 6.4717°N 55.0033°W, depth 33 m, triangular dredge, 25 April 1969 ; RMNH Por. 9323, 9370, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 107, 7.7°N 57.5°W, depth 65 m, muddy sand bottom with shells, 5 September 1970 ; RMNH Por. 9356, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 96, 6.8667°N 57.5167°W, depth 23 m, muddy sand and shells, 3 September 1970 ; RMNH Por. 9767, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 95, 6.9°N 57.5°W, depth 23–24 m, mixed hard bottom, 3 September 1970 ; RMNH Por. 9808, Suriname, ‘Luymes’ Guyana Shelf Expedition, station 5, 6.6°N 53.55°W, depth 44 m, trawl, bottom calcareous sand, 24 August 1970 ; RMNH Por. 9829, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 94, 6.9333°N 57.5°W, depth 26 m, bottom muddy sand and shells, 2 September 1970 ; RMNH Por. 9832, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 87, 7.5667°N 57.2667°W, depth 59 m, bottom sand and shells, 2 September 1970 ; RMNH Por. 9881, 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. 9945, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 63, 7.5833°N 57.0667°W, depth 71 m, sandy bottom, 31 August 1970 ; RMNH Por. 9971, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F38, 7.23°N 56.4067°W, depth 81 m, 5 May 1966 .

Description. ( Figs 41 a,a1) Strongly conulose branches, longest among the numerous collected specimens was 86 cm. Branches may be single, but usually have longer or shorter side branches in a low frequency. Thickness around 1 cm, with conules making up about half or more of that. Color in alcohol various shades of dark red to brown. Consistency firm.

Skeleton. An axially condensed reticulation of oxeas and styles, with the latter in ascending tracts and the oxeas interconnecting. Extra-axial skeleton consisting of single styles surrounded by bundles of thin crooked ‘cladostyles’, 80–100 µm in diameter, forming the characteristic conical surface projections.

Spicules. ( Figs 41 b–e) Long styles, oxeas, ‘cladostyles’, trichodragmas.

Long styles ( Figs 41 b,b1) of the conules and ectosomal region, smooth, slightly curved, about equidiametrical over much of the length, 538– 992 – 1398 x 16 – 25.1 –32 µm.

Oxeas ( Figs 41 c,c1), curved, gradually or abruptly, sharply pointed, 324– 406 –482 x 13 – 19.7 –23 µm.

‘Cladostyles’ of the conules ( Figs 41 d,d1), thin, crooked or sinuous, equidiametrical, the opposite end of the normal rounded head end transformed to a multipronged apex ( Fig. 41 d1), 267– 370 –439 x 3.5– 5.2 –7 µm.

Raphides in trichodragmas ( Figs 41 e,e1), 105– 118 –129 x 7 – 8.4 –10 µm.

Distribution and ecology. Guyana Shelf, NE Brazil, sandy bottom at 12–81 m depth ( Guyana Shelf 23–81 m).

Remarks. The present specimens conform closely to Ridley & Dendy’s description, including the peculiar ectosomal ‘cladostyles’ (sinuous styles with pronged apices). A second Central West Atlantic species is Thrinacophora spinosa Wilson, 1902 (p. 400), which is also quite similar in most aspects but lacks the pronged endings of the ectosomal styles. This latter feature is confirmed from examination of slides of the holotype USNM 7686. One further difference is the lesser thickness of the oxeas in T. spinosa (250–300 x 6–10 µm).

Figures

FIGURE 41. Thrinacophora funiformis Ridley & Dendy, 1886, a, habitus of RMNH Por. 9847 (scale bar = 1 cm), a 1, detail of one of the branches in a (scale bar = 1 cm), b – e, SEM images of spicules, b, style, b 1, details of b, c, oxea, c 1, details of c, d, ‘ cladostyle’, d 1, details of d, e, trichodragma, e 1, detail of e showing individual raphides.