Morphological description (show/hide)
| Thin-walled, lamellate, cup shaped sponges, 95-190mm high, 70-170mm maximum diameter, lamellae 2-4.5mm thick. Lamellae typically do not rejoin completely, usually producing asymmetrical cups. Apical margins of lamellae usually even, but larger specimens may consist of 2-4 concentric cups inside each other, with lamellae forming spiral walls. Sponges attached to substrate by large, flat basal plates, up to 55mm maximum diameter, with short, thick stalk, 14-36mm long, 14-28mm diameter. | | Live colouration dark maroon brown (Munsell 2 | | Firm, slightly compressible texture, sandpaper-like to touch. | | Surface features: Smooth, even, uninterrupted by any surface processes. Microscopically surface with minute conules. Oscules not seen, but small evenly distributed pores, up to 0.8mm diameter, scattered over surface of lamellae. | | Skeleton slightly axially compressed, plumo-reticulate, with plumose component emphasized only slightly over reticulate component of skeleton: former consisting of multispicular ascending tracts, latter with paucispicular, connecting tracts, both enclosed within spongin fibres. Spongin fibres light but well developed, with small mesh sizes, up to 90um maximum diameter. Mesohyl with moderate quantities of brown-pigmented collagenous spongin, and only few spicules dispersed outside fibres. Choanocyte chambers oval, 28-90um diameter. | | membranous, without specialised spiculation, but with regularly spaced plumose brushes, composed of 3-8 oxeas, from ascending extra-axial tracts, protruding through surface for short distances, up to 100um from ectosome. Position of plumose spicule brushes on surface coincides with minute surface conules. Subectosomal region predominantly plumose, slightly plumo-reticulate, with ascending plumose portion of skeletal tracts greatly emphasised over uni- or paucispicular reticulate, transverse, connecting tracts. Spongin fibre mesh size in peripheral skeleton up to 140um diameter, more open than in axial region. | | Megascleres oxeas without any modifications, relatively long, slender, slightly curved centrally, tapering to sharp fusiform points, with very few examples bearing stepped points.Holotype: 167-252.2-270 x 5.2-11.9-15.0 Other 152-238.8-283 x 3.6-10.7-16.2 | | nil |
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