Sponges of the Guyana Shelf Author Van, Rob W. M. text Zootaxa 2017 1 1 225 journal article 37320 10.5281/zenodo.272951 e2c88f4c-3ac2-45f9-95e4-99b75561a081 1175-5326 272951 6D68A019-6F63-4AA4-A8B3-92D351F1F69B Haliclona (Gellius) aff. flagellifera ( Ridley & Dendy, 1886 ) Figures 16 a–e Restricted synonymy: Desmacella sp. Schmidt, 1870 : 53 , pl. V fig. 15. ? Gellius flagellifer Ridley & Dendy, 1886 : 333 ; Ridley & Dendy 1887 : 42 , Pl. XIII figs 5, 10. Haliclona flagellifera ; Van Soest 1980 : 25 ; De Weerd, 2000 : 64 . Material examined. RMNH Por. 9783, 9851, 9921, Suriname , ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M97, 7.3083°N 54.1667°W , depth 130 m , bottom coarse sand, 16 April 1969 . Description. ( Fig. 16 a) Encrusting with lobes and upright lamellar projections. The three samples were obtained from the same station, but were disintegrated in small cm-sized fragments making it difficult to describe the overall shape in more detail. The surface is irregular, punctate, with small oscules elevated on low cushions. The color (in alcohol) is pinkish light brown. The consistency is soft and fragile. FIGURE 16 . Haliclona (Gellius) sp. aff. flagellifera (Ridley & Dendy, 1886) , a, habitus of RMNH Por. 9783 (scale bar = 1 cm), b, light microscopic image of surface skeleton of ditto, c–e, SEM images of spicules of RMH Por. 9921, c, oxea, d, flagellated sigma, e, sigma. Skeleton. ( Fig. 16 b) The choanosome shows a loose reticulation of ascending tracts which have 2–3 spicules and interconnecting single spicules, but overall the skeleton is rather confused without binding spongin. The surface skeleton is unispicular, but it is discontinuous where there are large subdermal spaces. Spicules. ( Fig. 16 c–e) Oxeas, flagellated sigmas, ‘normal’ sigmas. Oxeas ( Fig. 16 c), slightly curved, elongated-fusiform, 226– 319 –358 x 11 – 12.7 –14 µm. Flagellated sigmas ( Fig. 16 d), strongly assymetrical, with the shorter apex angularly incurved and the longer apex at first curving in and at the end curving out again, longer axis 72– 109 –159, shorter axis 51– 63 –75 µm. Normal sigmas ( Fig. 16 e), symmetrical, with slightly incurving apices, 42– 51.5 –56 µm. Distribution and ecology. Guyana Shelf, Florida , Belize , elsewhere reported from all over the world ( type locality is Marion Island in the Southern Indian Ocean), depth in the region: 20–410 m , elsewhere down to 1378 m . Remarks. This very characteristic species comprises most likely a species complex, because the published records encompass an almost cosmopolitan distribution: e.g. the Southern Ocean ( Ridley & Dendy 1886 ), the Arctic Ocean ( Lambe 1896 ; Lundbeck 1902 ), Indian Ocean ( Dendy 1922 ; Burton 1928 ), Mediterranean ( Vacelet 1969 ; Pulitzer-Finali 1978 ), and Namibia ( Uriz 1987 , 1988 ). We may expect that a detailed comparative analysis of all the reported specimens will yield small differences. This is supported by the descriptions of several species with closely similar spiculation, e.g. Indonesian Gellius incrustans Hentschel, 1912 , Californian Gellius edaphus De Laubenfels, 1930 , and New Caledonian Gellius antarius Lévi & Lévi, 1983 . A revision of Haliclona species with these flagellated sigmas is urgent. The Caribbean occurrence was already noted by Schmidt (1870) as Desmacella sp. encrusting a Florida Pachastrella abyssi . There is an unpublished specimen in the ZMA collection from 20 m off the Caribbean Colombian coast ( ZMA Por. 21962, collected by M. Kielman ). Van Soest (1980) and De Weerdt (2000) referred to a specimen with flagellated sigmas from Belize present in the Natural History Museum in London.