Darwinella corneostellata

(Carter, 1872)

Species Overview

Darwinella corneostellata (Carter, 1872) is an encrusting, rose-violet, strongly conulose sponge, resembling the purple colour form of Aplysilla rosea , but differing from in the possession of multi-rayed spongin spicules (microscopic examination). It is a rare species recorded once from NW Spain and dubiously from South Africa.

Taxonomic Description

Colour: Rose-violet in alcohol (possibly yellow in life).
Shape, size, surface and consistency: (Darwinella corneostellata 2) Thickly encrusting shells, forming low hummocks with terminal oscules which are slightly sunken in. Surface strongly and sharply conulose. Consistency soft.
Spicules: No proper siliceous or calcareous spicules, but these are mimicked by multi-rayed spongin spicules, ray number 5-7, size of rays 800 µm, diameter of spicules up to 1620 µm.
Skeleton: Single dendritic spongin fibres, up to 110 µm at the base, run from the substrate to the surface, where they form the conules. Basal spongin plate.
Ecology: No data.
Distribution: Bay of Vigo, NW Spain.
Etymology: The name refers to the multirayed horny spicules of this species.
Type specimen information: No data.

Remarks

Pronzato (1975) synonymized South African Darwinella warreni Topsent (1905) with the present species, thus considerably extending the distribution. In view of that and of (small) differences between the descriptions of the specimens, this synonymy is not adopted here.
Source: Topsent, 1905.