Crella digitifera

(Lévi, 1959)

Species Overview

Crella digitifera (Lévi, 1959) has erect branches issuing from a thick basal mass. Its colour is greenish. It is a southern species originally described from West Africa but also cited from Roscoff.

Taxonomic Description

Colour: Greyish green.
Shape, size, surface and consistency: Massive basis of 2 cm thick, with fairly weak prolongations of 3 cm long and 1.5 cm diameter sticking up from it. Surface even and smooth; "skin" stretched over subdermal canals. Consistency soft.
Spicules: (Crella digitifera spics) Megascleres : Tornotes are fusiform oxeotes, straight, often faintly polytylote, with irregular mucronate or lanceolate points: 250-270 x 6-9 µm; ectosomal acanthostyles curved regularly, entirely spined: 130-135 x 5-6 µm; basal acanthostyles, straight, finely spined: 130-150 x 8-10 µm.
Microscleres : Arcuate chelae of normal shape: 20 µm.
Skeleton: Ectosomal : a feltwork of tangential acanthostyles. Choanosomal : irregular columns of tornotes, mixed with acanthostyles; these same acanthostyles are distributed everywhere in the choanosome.
Ecology: On pebbles in deeper water, 60-75 m.
Distribution: Gulf of Guinea (W Africa), Mediterranean, Roscoff.
Etymology: The name refers to the surface prolongations.
Type specimen information: The type is in the Muséum National d'Histoire Naturelle, Paris.

Remarks

This species is closely related to C . rosea , which is also a rather elaborate Crella and has similar spiculation. The colour of that species is more orangeish and prolonged digitations are not known. Since the record of C . digitifera from Roscoff was not accompanied by a description it needs to be confirmed by re-examination of the specimen in the collections of the Station Biologique.
Source: Lévi, 1959.