Spinularia spinularia

(Bowerbank, 1866)

Species Overview

Spinularia spinularia (Bowerbank, 1866) is a deep water Polymastia-like sponge differing from species of that genus in the possession of trichodragmata. It has been recorded from the Shetlands and from SW Ireland.

Taxonomic Description

Colour: Grey with a tint of green in dry condition.
Shape, size, surface and consistency: Cushions of several cm in diameter and thickness, with one or several papillae, which may bear oscules. Surface optically smooth on the upper parts, but may be hispid on the sides, due to long projecting spicules.
Spicules: Tylostyles: 300-1200 µm, possibly in several size categories. Trichodragmas: 70-300 µm.
Skeleton: Radiate arrangement at the surface, with long tylostyles protruding beyond the ectosome; choanosomal skeleton consisting of long radiating tracts of tylostyles.
Ecology: On gravel bottom, 80-4000 m.
Distribution: Shetlands, SW Ireland, Sweden, Norway; Azores.
Etymology: The name refers to the tylostyles, which were dubbed "spinulate" spicules by Bowerbank.
Type specimen information: ?, BMNH 1910.1.1.34 A and B (dry), Norman Collection, Shetland 1841. Rev. A Norman. Also slides "probably from type" unregistered (Bk. 393).

Remarks

The species is retained in its own genus, despite strong similarities with Polymastia , because of the absence of tangential spicules and presence of trichodragmas.
Source: Stephens, 1914.