Wörheide & Hooper, 1999 : 865 adusta Voigt et al. 2017 : 5 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 84LYT Van & De 2018 [151,241,152,178] Calcarea Clathrinidae Arturia GBIF Animalia Clathrinida 24 25 Porifera genus     Clathrina adusta  Wörheide & Hooper, 1999: 865, figs 4D–H.  Ernstia adusta; Klautau et al.2013: 12.    Arthuria adusta; Voigt & Wörheide 2016: 61    Clathrinaaff. adusta;  Voigt et al.2017: 5, fig. 3.     Materialexamined. ZMAPor. 10612, Seychelles,  La Digue Island, Scoast, 4.3833°S 55.8333°E, depth  2–8 m, snorkling, coll. R.W.M. van Soest, field nr. NIOP-E stat. 735/ 32, 23 December1992.   Description.Cormus a small cushion ( Fig. 5a), about 1 x 0.7 cmin lateral expansion, thickness 2–4 mm. Life color is unknown, in alcohol it is orange-yellow. Structure compact, made up of tightly anastomosed thin tubuli. No visible oscules. Consistency soft.   FIGURE 5.  Arturia(?)  adusta(Wörheide & Hooper, 1999), ZMA Por. 10612, from the Seychelles, La Digue island, a, preserved habitus (scale bar = 1 cm), b, light microscopic image of cormus showing tight anastomosis of tubuli, c–e, SEM images of the spicules, c, triactines, d, tetractines, e, detail of apical actine of tetractine.  Aquiferous system.Asconoid.  Skeleton.( Fig. 5b) Wall of tubuli thin, consisting of one-two spicule layers with a prominence of triactines. The apical actines of the tetractines are protruding into the tubule lumina.  Spicules.( Figs 5c–e) Triactines and tetractines, the latter present in clearly smaller numbers. No distinct trichoxeas were found. Triactines ( Figs 5c) equiradiate and equiangular, with conical actines, some verging toward tripod-shape; actine sizes 48– 76–108 x 6.5– 8.7–12 µm. Tetractines ( Figs 5d) of similar shape and size to the triactines, actines of the basal triradiate system 54– 73– 87 x6.5– 7.6–9.5 µm; apical actines ( Fig. 5e) smooth, straight, sometimes with a slightly upturned apex, 39– 55– 78 x 3– 5.9–7.5 µm.   Distribution and ecology.Egyptian Red Sea ( Voigt et al.2017), Seychelles, NE Australia, on reefs in shallow depths.   Remarks.We base our identification largely on the sequence we obtained for our species, which ended up in a clade together with Voigt et al.’s (2012)Australian sequence of  Arturia adustaand Voigt et al.’s (2017)Red Sea  Clathrinaaff. adusta(see his fig. 3). Klautau et al.(2013) had earlier assigned  Clathrina adustato Ernstia. Voigt & Wörheide (2016) discovered that this species falls outside the Ernstiaclade and suggested that it should go to  Arturia. We confirm that  C. adustais not an Ernstia, but with Voigt et al.(2017)we agree that assignment of  C. adustato  Arturia s.s.is probably not correct, because  Arturia suezianaand the typespecies of the genus  Arturia, did not group in the same clade as  C. adusta(see discussion above). The present specimen resembles the type of Wörheide & Hooper (1999), although the white color cannot be affirmed. In glutaraldehyde the color of the type apparently changed to dark brown. Actine sizes 90–142 x 12–20µm, more robust than in the Seychelles specimen, but overlapping. Voigt et al.’s (2017)record from the Red Sea mentioned actine sizes of 66– 73 x 9–10µm, more similar to our specimen than to the type. The three sequences for these specimens differed only in a few sites (two between the type and the Seychelles specimen, three between the type and the Red Sea specimen). 1848255682 ZMA La Digue Island, S & R. W. M. van Soest Seychelles 5 -4.3833 Material 7 55.8333 La Digue Island 24 25 1