Form: Forms thin patches with no excurrent channels visible and very inconspicuous osculae. Surface has hispid appearance and is sometimes lightly silted. Patches very variable in size, from 3–20 cm maximum diameter.
Colour: Bright orange/red.
Surface: Slightly hispid with projecting spicules. Usually clean but with small amounts of silt or sand.
Apertures: There are no obvious oscules or excurrent channels.
Skeleton: Choanosome has ascending fibres of bundles of three or four smooth styles with a ladder-like reticulation of acanthostyles. Toxas of three sizes and chelae present in choanosome, small toxas very abundant. Splayed bundles of thin subtylostyles form the ectosome, these echinate the surface.
Spicules: Choanosomal smooth styles vary widely in size, 240–850 by 6–14 μm. Choanosomal acanthostyles are 150–180 by 10–12 μm, entirely spined with small gritty spines, these are denser on the head. Ectosomal styles are 410–500 by 2–3 μm, the head is very slightly tylote and microspined. Toxas are in two categories. The smaller ones are 30–100 by 0.5–2 μm, very abundant in the choanosome. The second, larger category is much scarcer, these measure 210–540 by 8–12 μm. Palmate isochelae measure 16–18 μm.
Habitat: Found on the sides of stable boulders in moderate to strong tidal streams at depths of 30-40m.
Distribution: Currently only known from the south and east coasts of Rathlin Island, Northern Ireland.
Editors: Bernard Picton & Claire Goodwin.
|Picton, B.E., Morrow, C.C. & van Soest, R.W.B., 2011. [In] Sponges of Britain and Ireland |
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