Eurypon clavatum

(Bowerbank, 1866)

Species Overview

Eurypon clavatum (Bowerbank, 1866) is a hispid, thin, yellow encrustation on pebbles and shells in deeper water off the west coasts of Britain and France.

Taxonomic Description

Colour: Bright yellow.
Shape, size, surface and consistency: Thinly encrusting on pebbles and shells. Size up to 2 cm in lateral expansion. Surface strongly hispid, hairy, due to projecting spicules. Oscules small and dispersed. Consistency soft.
Spicules: (Eurypon clavatum spics) Smooth long styles to tylostyles: up to 1500 x 18 µm; short thin styles: 500 x 3 µm; acanthostyles, of extremely variable length, the smaller entirely spined, the larger partly smooth: 65-600 µm.
Skeleton: Smooth styles erect on the substrate surrounded by acanthostyles; thin styles form bundles or bouquets at the surface where the shaft of the smooth styles pierce the surface membrane.
Ecology: On pebbles, bryozoans and Lophelia , from 45 m downwards to at least 1300 m.
Distribution: Shetlands, Roscoff, Iles de Glénan, SW Ireland, Norway.
Etymology: Clavatus (Latin) = club-shaped, referring to the shape of the tylostyles.
Type specimen information: The type is in the Natural History Museum, London.

Remarks

This species is close to Eurypon coronula in habit, colour and spicule sizes, but that species has peculiar whorls of spines on the acanthostyles.
Source: Arndt, 1935.