Eurypon radiatum

(Bowerbank, 1866)

Species Overview

Eurypon radiatum (Bowerbank, 1866) is a thinly encrusting, presumably reddish or orange sponge, with microhispid surface. It is known from only a few records off north coasts of the British Isles.

Taxonomic Description

Colour: Live colour unknown, possibly reddish or orange; light greenish grey in dry condition.
Shape, size, surface and consistency: Very thinly encrusting, up to several cm2. Surface even, almost smooth, although the larger spicules may protrude through the peripheral membrane. Oscules small and dispersed. Consistency unknown, presumably soft.
Spicules: (Eurypon radiatum spics) Long styles, with slightly swollen heads: size unknown but >800 x 10-15 µm; smaller ectosomal styles: ca. 350 µm; acanthostyles, entirely spined, in a wide size range, possibly in two size categories: 100-400 µm (these sizes have been extrapolated from Bowerbank's (1874) drawings).
Skeleton: Long styles stand singly erect on the substrate, surrounded by acanthostyles; at the surface smaller styles from radiating bouquets.
Ecology: On pebbles and Pecten shells.
Distribution: Shetlands, Hebrides.
Etymology: The name refers to the radiating bouquets of smaller styles.
Type specimen information: The type is in the Natural History Museum, London.

Remarks

This species has never been redescribed properly since its original description by Bowerbank. Thus many of its characters are poorly known. From what we know its characteristic feature is the radiating surface bouquets.
Source: Bowerbank, 1866, 1874.