Calcareous sponges of the Western Indian Ocean and Red Sea Van, Rob W. M. De, Nicole J. Zootaxa 2018 2018-06-01 4426 1 1 160 Van & De, 2018 Van & De 2018 [151,348,152,178] Calcarea Clathrinidae Leucetta GBIF Animalia Clathrinida 84 85 Porifera species sulcata sp. nov.     Materialexamined. Holotype, RMNHPor. 11639, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.76203°S 63.46273°E, depth  10 m, scuba, coll. N.J. de Voogd, field nr. ROG042,  17 October 2016.   Paratypes, RMNHPor. 11643, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.76203°S 63.46273°E, depth  10 m, scuba, coll. N.J. de Voogd, field nr. ROG046,  17 October 2016;  RMNHPor. 11645, Mauritius, Rodrigues, Mourouk Ebony, Castel Rock, 19.76203°S 63.46273°E, depth  10 m, scuba, coll. N.J. de Voogd, field nr. ROG048,  17 October 2016.  ? Additionally: ZMAPor. 1 6368, Madagascar, Nosy Bé, Ambariobé, Nof Kosy Komba, depth  6–8 m, scuba, coll. J.H. Stock,  28 December 1963.   Description.The in situ shape is a massive lumpy sponge ( Fig. 49a) with irregular grooves and deep holes. Live color pale greyish white with pink rims in the peripheral parts. Surface irregular, in places somewhat conulose. Oscules inconspicuous, almost flush with the surface. Color of specimens on deck ( Fig. 49b–c) and preserved ( Fig. 49d) remains the same. Size of preserved specimens up to 13 x 8 x 8cm, oscules 5 mmin diameter. Grooves and ridges up to 1 cmwide. Consistency coarse, harsh and hard.  Aquiferous system. Leuconoid.  Skeleton.A dense mass of giant triactines and small triactines. The oscules lead to into round atrial cavities lined with tetractines and triactines.  Spicules.( Figs 50a–d) Giant triactines, small triactines, tetractines. Giant triactines ( Figs 50a) equiradiate, equiangular, 408– 984–1380 x 43– 107.2–204 µm. Small triactines ( Figs 50b) equiradiate, equiangular, 124– 186–241 x 10– 16.8–22 µm; small sagittal triactines with wavy paired actines (not shown), 83– 106–133 x 7– 10.2–14 µm. Tetractines ( Figs 50c–d) with basal triradiate system similar to triactines, 102– 163–204 x 9– 12.6–16 µm, apical actines thin, curved ( Fig. 50d), 29– 58– 96 x 3– 5.2–8 µm.   Distribution and ecology. Rodrigues, possibly Madagascar, on reefs in shallow depth.   Etymology.Sulcatus (L.) meaning grooved, referring to the habitus.   Remarks.The spicule sizes and shapes are similar to those of  Leucetta microraphis, to which the present species is most closely related. Two small irregular fragments of a white sponge, ZMA Por. 16368, collected near Nosy Bé, Madagascar, could belong to the present species based on its skeleton and spicules, but the small material without a definite shape precludes a definite conclusion. We obtained sequences of the holotypeand two of the paratypesand in our phylogenetic analysis ( Fig. 2C) they grouped together (at 85% bootstrap value) in a larger clade containing sequences of  L. microraphisfrom  Mayotte, Madagascar, Australiaand the Red Sea. Aligned and trimmed sequences of this larger  L. microraphis- group (length 396 sites), showing 19 non-conserved sites, resulted in observed differences of 2–8 sites between  L. sulcata  sp.nov.and various sequences of  L. microraphis s.l.The four sequences of  L. sulcata  sp.nov.shared two unique non-conserved sites. The three sequences of  L. microraphiswith pinkish red-brown-green color, described above from  Mayotteand Madagascar, shared three unique non-conserved sites. These were not shared by the one Indonesian sequence of a specimen with similar morphology as the  Mayotteand Madagascarspecimens. Remarkably, Oliver Voigt’s Red Seasequences did not have any uniquely shared sites, individual sequences sharing non-conserved sites variously with  L. sulcata  sp.nov.or WesternIndian Ocean  L. microraphis, and the Australian and Indonesian sequences. Clearly, the morphological discrepancies and inconsistencies in  L. microraphis s.l.are not easily solved by molecular sequence data.  L. microraphis s.l.are likely a complex of sister species. The morphological differences of the present new species (white color, grooved and holed habitus) with  L. microraphis s.s.(pinkish red-brown-green tubular masses) preclude conspecificity. The pink-white Red Seaspecimens and  L. pyriformisspecimens described above are additional members of the group, differing in shape, color and e.g. in the long straight vs. curved condition of the apical actines of the tetractines. More study is necessary to differentiate the species.  Leocorny et al.(2016)recently studied the  Leucettaspecies from (sub-)tropical Australian waters:  Leucetta prolifera( Carter, 1878)(originally as  Teichonella),  L. insignis Row & Hozawa, 1931,  L. infrequens Row & Hôzawa, 1931,  L. expansa Row & Hôzawa, 1931,  L. villosa Wörheide & Hooper, 1999,  L. foliata Leocorny et al., 2016and  L. purpurea Leocorny et al., 2016. Of these species, two are slightly similar to the new species in having a folded habitus,  L. proliferaand  L. foliata, but the former has the folds broadly bladed with rows of oscules on the upper surface of the folds, whereas the latter has the folds sharply and thinly bladed. Both do not really resembly the irregularly grooved-holed specimens of the new species. Both species have next to the usual complement of giant triactines, small triactines and small tetractines also large tetractines of the same size or larger as the giant triactines. The remaining species have a more compact or globular habitus, also unlike our new species:  L. insignisis shaped like  L. chagosensisbut has tripod-like giant triactines,  L. infrequensis a small erect clump, which apparently lacks small tetractines,  L. expansais also a small, but squat clump, possessing ectosomal microdiactines in addition to the usual spicule complement,  L. villosais provided with villous hair-like outgrowths on the surface, and finally  L. purpureais a small globular purple-colored sponge with giant tripods, sharing this feature with  L. insignis. 1848255681 2016-10-17 RMNH N. J. de Voogd Mauritius Material 10 -19.76203 Castel Rock 1 63.46273 Mourouk Ebony 84 85 1 Rodrigues holotype 1848255688 2016-10-17 RMNH N. J. de Voogd Mauritius 10 -19.76203 Castel Rock 1 63.46273 Mourouk Ebony 84 85 1 Rodrigues paratype 1848256252 2016-10-17 RMNH N. J. de Voogd Mauritius 10 -19.76203 Castel Rock 1 63.46273 Mourouk Ebony 84 85 1 Rodrigues paratype 1848256128 1963-12-28 ZMA Ambariobe, N & J. H. Stock Madagascar Kosy Komba 7 Additionally Nosy Be 84 85 1