DefinitionPetrosiidae with finely hispid surface produced by fine brushesof oxeas issued from subectosomal tracts, and a compact choanosomalnetwork combining rounded meshes with a superimposedanisotropic reticulation. Megascleres oxeas less than 200 fLm long.DiagnosisCompact sponges (Fig. 2A), with an ectosomal unispicularisodictyal layer and free-brushes of oxeas, producing a finelyhispid, smooth, 'velvet-like' surface (Fig. 2B). Ectosomal skeletona tangential isodictyal network with one size of spicule (Fig. 2C),spongin and spicule brushes only at nodal points, free spiculesabundant. Consistency hard, stony, spongin always scarce.Subdermal region with short spicular tracts, limited by a secondsurface skeleton layer, 'peripheral condensation' (Fig. 2D, arrow),or a 'paper-thin area about 1 mm below the surface' (seede Laubenfels, 1953b: 18). Choanosomal skeleton a compact networkof irregular paucispicular tracts with rounded meshes, irregular insize. Megascleres: oxeas, less than 200 fLm long.DistributionCentral West Atlantic, Indo-West Pacific.Previous reviewsDuchassaing, 1850: 26; Green, 1977: 88; Wiedenmayer,1977b: ll3, pI. 14, figs 1-5, text-fig. 128 (as 'Xestospongia subtriangularis'(Duchassaing), synonymy from Van Soest, 1980: 72).Description of type speciesHaliclona longleyi de Laubenfels, 1932.Synonymy. Haliclona longleyi de Laubenfels, 1932: 54;1936a: 44, pI. 7, fig. 1, pI. 8, fig. 2. Neopetrosia longleyi deLaubenfels, 1949b: 10.Material examined. Lectotype (here designated): USNM22475 - near Bird Key, Florida Keys, Dry Tortugas, Gulf ofMexico. Schizolectotypes: BMNH 1936.4.8.42 (slide, fromde Laubenfels' specimen).Description. Ramose 30-40 cm high, anastomosingbranches 2-5 cm in diameter, erect, with finger-like flattened roundlobes (Fig. 2A), fixed to the substratum by a narrow basal portion.Several oscula scattered on one face of the branches, 3-8 mm indiameter, sometimes surrounded by a collar. Surface smooth,extremely porous, rough, minutely hispid. No special surfaceskeleton. Texture very hard, compact, aquiferous system withoutlarge spaces. Colour alive is yellow green on those surfaces whichare most exposed to light, and dark olive green on shaded surfaces.Ectosomal skeleton a tangential isodictyal dense surface networkcomposed of one spicule length, with spongin present only at thenodes. Surface hispidation is produced by fine spicule brushes issuingfrom the nodes of meshes. Abundant free spicules are present.Subectosomal region appears as a compact irregular network ofshort spicular tracts. About 1 mm below the surface there is a secondlayer of the same appearance as the surface, described as a'paper-thin area about 1 mm below the surface' (de Laubenfels,1953b: 18). In longitudinal sections this layer is very net-like, easilyobserved (Fig. 2D). Choanosomal network confused with irregularmeshes formed by irregular multi- to paucispicular fibres,3-20 spicule-rows, ("often more than 20", de Laubenfels, 1932),coated by a fine spongin sheath. No interconnecting tracts, but 1-3spicules are joined by scarce spongin between tracts. Divergentfree ends of longitudinal tracts form the ectosomal skeleton(Fig. 2D). Megascleres: are bent oxeas, 104-120-144 fLm long,2-3-4 fLm wide, usually of only one size class.DistributionDry Tortugas, Florida, near Bird Key Reef, 1 m depth(de Laubenfels, 1932), Western Bahamas (de Laubenfels, 1949b
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