Form: Thin sheets, up to 10cms across, often growing over barnacles. (? In erect form, "short, cylindrical, angular, club-shaped sponges, becoming massive, lobed, and lobulated, or compressed and expanded flabellately", up to 12cms in height).
Colour: Wine red, "vivid red". (Greyish yellow in alcohol, light buff yellow when dried).
Surface: Uneven, finely hispid. With "depressions and elevations".
Apertures: Oscules minute. Pores "inconspicuous"; grouped in sieves according to Boury-Esnault and Lopes, 1985.
Contraction: ? oscules contract on collection.
Skeleton: In crust form, styles echinate the sponge base, with their heads on the substrate, and their points projecting beyond the ectosome to give the hispid appearance. Vermiform spicules may be heavily concentrated at the base of the sponge, or dispersed throughout.
Spicules: Styles (a) are slender, up to 3000Ám in length (Arndt states 130Ám, presumably in error). The vermiform spicules are oxea (b) and perhaps strongyles, that are robust, irregular and crooked; 280-600Ám (?) in length. Microscleres are absent.
Habitat: On pebbles, and bivalve shells. The more extensive sheets develop on rock surfaces. Reported growing on deep water coral, and amongst beds of Sabellaria spinulosa at 60-70m.
Distribution: Recorded from many parts of the Atlantic and Mediterranean. Off UK shores, recorded from the north of Scotland, Shetland and to the Faroe Islands. Recorded recently from Skird Rocks (Galway Bay), St. John's Point (Donegal) and Kenmare River (Kerry), in Ireland. Found from relatively shallow water (less than ca. 25m) to about 3000m.
Distribution Map from NBN: Grid map (fast) : Interactive map (slower, requires login to view records) : National Biodiversity Network mapping facility, data for UK.
Identity: The crust form is difficult to distinguish from other red crusts by sight, but the vermiform spicules are characteristic. The erect form can be distinguished from other erect sponges by the presence of vermiform spicules, and from other species of Phakellia (which also possess vermiform spicules) by the more regular cup or lamellate shapes of the latter (see Phakellia ventilabrum, q.v.). N.B. It is not certain whether there are two forms of Phakellia vermiculata that are ecologically (and genetically?) distinct, or whether a crust will eventually develop into an erect form. The former view has prompted the separation of the erect form into a variety (synonym 3 above) and a species (synonym 4).
Voucher: BELUM : Mc572. Skird Rocks, Galway.
Editors: D.Moss, B.E. Picton.
|Picton, B.E., Morrow, C.C. & van Soest, R.W.B., 2011. [In] Sponges of Britain and Ireland |
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