Mycale (Mycale) quadripartita Boury-Esnault, 1973

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 160-161

Mycale (Mycale) quadripartita Boury-Esnault, 1973

Figures 100 a–l

Mycale quadripartita Boury-Esnault, 1973: 278 , pl. II fig. 2, text-fig. 31.

Mycale (Mycale) quadripartita ; Hajdu & Desqueyroux-Faúndez 1994: 582, figs, 55–63.

Material examined. RMNH Por. 6310, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station A28, 6.5667°N 55.255°W, depth 37 m, Van Veen grab, 28 April 1966 (1 specimen) ; RMNH Por. 7421, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F46, 6.312°N 56.57°W, depth 25–29 m, bottom sand, 7 May 1966 (2 specimens) ; RMNH Por. 9394, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F45, 6.4417°N 56.5467°W, depth 34 m, Van Veen grab, 7 May 1966 (1 specimen) ; RMNH Por. 9739, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 104, 7.9°N 57.555°W, depth 80 m, bottom muddy sand, Van Veen grab, 4 September 1970 (1 specimen) ; RMNH Por. 9781, Guyana, ‘ Snellius O.C.P.S. ’ Guayana Shelf Expedition , station E66, 7.1°N 56.178°W, depth 65 m, Agassiz trawl, 10 May 1966 (1 specimen) ; RMNH Por. 9845, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station E5, 6.8217°N 56.2225°W, depth 44 m, dredge, 6 April 1966 (1 specimen) ; RMNH Por. 9856, 9857, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M88, 6.7133°N 53.975°W, depth 48 m, bottom muddy sand, 12 April 1969 (2 specimens) ; RMNH Por. 9907 Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station G7, 7.28°N 56.7933°W, depth 64 m, bottom sand, 7 May 1966 (2 specimens) .

Description. ( Fig. 100 a) Upright fistules, occasionally provided with a thinner stalk-like part (in life presumably buried in the sand), length 1–2 cm, diameter 3–5 mm. Color in alcohol pale greyish brown. Consistency compressible, with tough skin.

Skeleton. The surface skeleton is a thick mass of intercrossing styles overlying large subdermal spaces. Choanosomal skeleton ( Fig. 100 a1) with a thick (0.5–1 mm diameter) central column of styles, from which issue at right angles and at regular distances four to five 0.5 mm thick spicule tracts fanning out into thinner tracts carrying the surface skeleton. Ectosomal skeleton crowded with rosettes of anisochela I ( Fig. 100 b) and fusiform trichodragmas ( Fig. 100 c).

Spicules. ( Figs 100 d–l) Styles, anisochelae, sigmas, trichodragmas.

Styles ( Figs 1 00d,d1,e), mycalostyles, fusiform, with narrow necks below elongate slightly swollen heads, in two size categories, (1) larger ( Figs 100 d,d1), 522– 644 –734 x 13 – 16.3 –19 µm, and (2) smaller ( Fig. 100 e), 341– 387 –462 x 8 – 10.7 –15 µm.

Anisochelae in three distinct size categories, the larger anisochela I ( Fig. 100 f) and the middle-sized anisochela II ( Fig. 100 g) similar in shape with broadly flaring upper alae, the smallest anisochela III ( Fig. 100 h) with more narrow alae; anisochelae I, 83– 87.2 –92 µm, anisochelae II, 42– 43.9 –46 µm, anisochelae III, 24– 27.1 –36 µm.

Sigmas, in a large size range, including very large ones, divisible in three (possibly four) size categories, (1) largest ( Fig. 100 i), 168– 200.2 –234 µm, (2) middle-sized ( Fig. 100 j), 54– 69.1 –78 µm, and (3) smallest ( Fig. 100 k), 13– 20.9 –29 µm.

Trichodragmas, shaped like tight, fusiform packages of about ten spicules, 45– 57 x 8–11 µm, individual raphides ( Fig. 100 l), 40– 50 x <1 µm.

Distribution and ecology. Guyana Shelf, North and East Brazilian coasts, on soft bottoms, 23–80 m depth (previously down to 60 m).

Remarks. This species has been clearly described and illustrated by previous authors ( Boury-Esnault 1973; Hajdu & Desqueyroux-Faúndez 1994). The present material represents the northernmost occurrence of the species, but from the dozen of specimens reported here it can be concluded it is rather common on the Guyana shelf.

Figures

FIGURE 1. Map of the northeast coast of South America showing the Guyana Shelf with 200 m depth contour and in the inset the area covered by the Dutch HMS ‘ Snellius’ O. C. P. S. 1966, HMS ’ Luymes’ O. C. P. S. II 1969, and HMS ‘ Luymes’ Guyana Shelf 1970 expeditions. Arrows indicate predominant current direction. Map courtesy of www. prima. com (map collection Free Edition).

FIGURE 100. Mycale (Mycale) quadripartita Boury-Esnault, 1973, a, habitus of RMNH Por. 9781 (scale bar = 1 cm), a 1, cross section of RMNH Por. 6310 (scale bar = 1 cm), b – c, light microscopic images of the spicules, b, rosette of anisochela I, c, trichodragmas, d – l, SEM images of the spicules, d, style, d 1, details of d, e, small style, f, anisochela I, g, anisochela II, h, anisochela III, i, large sigma, j, intermediate sized sigma, k, small sigma, k 1, enlarged image of k, l, raphide.