Wiedenmayer 1977 :86 Soest 1980 :31 Marine sponges (Porifera: Demospongiae) from the Gulf of México, new records and redescription of Erylus trisphaerus (de Laubenfels, 1953) Ugalde, Diana Gómez, Patricia Simões, Nuno Zootaxa 2015 3911 2 151 183 D3MW Duchassaing 1850 Duchassaing 1850 [151,713,368,394] Demospongiae Niphatidae Amphimedon Animalia Haplosclerida 23 174 Porifera species complanata   Material examined. CNPGG–1207 Sisal Banks reefs ( 21º26'28.3”N, 90º17'34.0”W), depth 10.5 m, 10/IX/2011. CNPGG–1208 Sisal Banks reefs ( 21° 26' 24”N 90° 28' 25.39”W), depth 6 m, 13/IX/2011. CNPGG–1285 Sisal Banks reefs ( 21º26'17''N 90º16'38''W), depth 9 m, 7/XI/2011.   Description. Mainly flabellate forms but flabellate-shape specimens with branches are also found ( Fig. 18A). Dimensions up to 23 cmhigh and 12 cmin its widest width. Numerous oscules scattered on the surface, 1–3 mmin diameter. The surface is smooth to microhispid, and its consistency is very compressible and flexible when alive. The color is all white when alive, and creamy or beige in alcohol.  Skeleton. The ectosomal skeleton is a poorly developed paratangential reticulum. The choanosomal skeleton is a fibro-reticulum with a tendency to become fasciculate, composed by thin ascending fibres cored by 0–8 spicules per cross section. Primary fibres are 100–170 µm in diameter. These are interconnected by secondary fibres 8–25 µm in diameter, cored by 0–2 spicules. Rectangular to round meshes are 70–500 µm ( Fig. 18B).  Spicules. Thin strongylotes 60–97 × 1–2.6 µm tapering towards the ends, approaching the shape of hastate oxea ( Fig.18C). In places authentic hastate oxeas are seen.   Distribution and ecology. Bahamas( Dendy 1890), Lesser Antilles (van Soest 1980); Jamaica(Lehnert & van Soest 1998), Florida ( Storr 1964); Cuba(Alcolado 2002).  Amphimedon complanatainhabits particularly shallow coral reef environments. The specimens were collected in reef areas where the coral rubble and sea grass were abundant, in depths from 6 to 11 m. This finding is a new record for Mexicoand the southern Gulf of Mexico.   Remarks.  Amphimedon complanataexhibited a consistently white color when alive, but purple or black specimens may also occur ( Duchassaing & Michelotti 1864). Unfortunately van Soest (1980)and Wiedenmeyer (1977) did not recorded live color and they only cite the color reported by previous authors. Regarding the sponge habit, a massive encrusting shape is cited for Jamaicaspecimens ( Lehnert & Soest 1998), different from the massive-to-flabellate and the massive-to-ramose (with upright branches) shape, with a strong tendency towards flabelliform habit reported in Duchassaing & Michelotti (1864)and van Soest (1980)respectively, as well as in the presently described material. A different surface structure with deep depressions connected by ridges is described from the Jamaican specimen, contrasting with the smooth to microhispid surface described by Duchassaing & Michelotti (1864), van Soest (1980)and the present work.