Carter, 1874b
Species Overview
Guitarra fimbriata Carter, 1874b forms whitish yellow cushions. The surface bears collared porefields and oscules on short chimneys. It occurs in deep water.
Taxonomic Description
Colour: Whitish yellow.
Shape, size, surface and consistency: Hemispherical cushions, about 2 cm high. On the upper surface there is a terminal oscule at the end of a chimney 3-4 mm high. Inhalant openings collected in raised porefields.
Spicules: (Guitarra fimbriata Carter) Megascleres (Guitarra fimbriata oxea): Oxeote or strongylote spicules, occasionally centrotylote: 260-500 x 4-8 µm.
Microscleres : Placochelas (Guitarra fimbriata placochelae) in two size classes (Guitarra fimbriata 2 placos): 40-65 and 90-105 µm; spined isochelas (Guitarra fimbriata chela): 13-17 µm
Skeleton: Ectosomal : Tangential oxeas arranged in bundles of 4-8. Choanosomal : a vague reticulation of thick spicule tracts (about a dozen spicules in cross section), forming meshes of 300-500 µm in diameter.
Ecology: On stones and vertical rock faces, locally abundant (up to 3 individuals per square m) at 55-80 m.
Distribution: NW and SW of the British Isles, Roscoff, Iles de Glénan.
Etymology: The name refers to the strongly proliferated fimbriae (connecting ridges between alae and shaft of chelae-type microscleres) observed in the placochelae.
Type specimen information: The type is in the Natural History Museum, London.
Remarks:
This is a widespread deep water species with characteristic spiculation, but with otherwise uncertain status because fresh specimens have not been recently described. Furthermore, along the Atlantic coasts of Spain two other closely related species G . laplani Boury-Esnault et al., 1993 (at depths exceeding 400 m) and G. solorzani Cristobo, 1998 (at depths of 38-50 m) have been recorded recently. G. laplani has only a single category of placochelae and the spined chelae look almost like normal palmate chelae. G. solorzani differs only clearly in the shape of the alae of the spined chelae, which are distinctly lobed. Both species are not included in our present Sponge Guide because their status vis-à-vis G. fimbriata needs clarification.
Source: Descatoire, 1966.