(Bowerbank, 1862)
Species Overview
Bubaris vermiculata (Bowerbank, 1862) is a an encrusting red sponge that may develop erect, lobes. The surface is irregular and the consistency is firm. Distinction from other red crusts with certainty is possible only after microscopic examination: it has distinctive vermiform spicules crowded at the base. It is a deep water sponge with a wide distribution from the Arctic to the Mediterranean.
Taxonomic Description
Colour: Wine-red, vivid red. Greyish yellow in alcohol, light buff yellow when dried.
Shape, size, surface and consistency: Thin sheets, up to 10 cm 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 12 cm in height. Surface uneven, finely hispid. With depressions and elevations. Oscules minute. Pores inconspicuous; grouped in sieves according to Boury-Esnault and Lopes (1985). Oscules contract on collection. Consistency firm.
Spicules: (Bubaris vermiculata spics) Styles and vermiform oxeas/strongyles. The styles are slender: up to 3000 µm (Arndt states 130 µm, presumably in error). The vermiform spicules are oxeas and perhaps strongyles, that are robust, irregular and crooked: 280-600 µm. Microscleres are absent.
Skeleton: (Bubaris vermiculata skel) 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.
Ecology: On pebbles and bivalve shells. The more extensive sheets develop on rock surfaces. Reported as growing on deep water coral and amongst beds of Sabellaria spinulosa at 60-70m. Found from relatively shallow water less than ca. 25 m to about 3000 m.
Distribution: Recorded from many parts of the Atlantic from the Arctic southward into the Mediterranean. In the Bristish Isles, recorded from the north of Scotland, Shetland and the Faroe Islands. Recorded recently from Galway Bay, Donegal and Kenmare River in Ireland.
Etymology: The name refers to the vermiform spicules.
Type specimen information: The type is in the Natural History Museum, London: BMNH 1930.7.3.86 (dry). MCS voucher: BELUM, Mc572, from Skird Rocks, Galway, Ireland.
Remarks
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 species of Phakellia (which also possess vermiform spicules) by the more regular cup or lamellate shapes ot the latter.
N.B. It is not certain whether there are two forms of Bubaris vermiculata that are ecologically (and genetically?) distinct, or whether a crust will eventually develop into an erect form. Ackers et al. (1992) assigned this species to Phakellia , but that genus has a distinctly reticulate skeleton and a persistently cup-shaped or flabellate form. If the genus Bubaris is considered to be based on characters of grade (encrusting-massively lobated) rather than on unique features, then it would fall to Acanthella rather than to Phakellia , because the former has a dendritic skeleton conforming to the architecture found in erect Bubaris .
Source: Ackers et al., 1992 (D. Moss and B.E. Picton)