Axinella alba

(Descatoire, 1966)

Species Overview

Axinella alba (Descatoire, 1966) is a white, encrusting Axinella with small fistule-like elevations. It is known only from a single record from the west coast of France.

Taxonomic Description

Colour: White.
Shape, size, surface and consistency: The only known specimen is an encrusting patch of 2.5 cm on which 3 thin elongated projections are erect, each about 5-8 mm long and about 1.5 mm in diameter. Possibly it is an immature specimen.
Spicules: Megascleres : Styles in two categories, I: longer-thicker: 250-1200 x 15-18 µm, and II: shorter and thinner: 260-950 x 3-10 µm; oxeas, 700-1000 x 15-18 µm. Microscleres : Trichodragmas: 40-60 µm.
Skeleton: In the basal crust there are bundles of styles I and oxeas traversing the body towards the surface; styles II and trichodragmas are scattered inbetween. In the projections, there is an axis of styles I surrounded by a palisade-like mass of styles II. Near the surface there are bundles of 5-6 styles I arranged in a plumose fashion. These form here and there surface bouquets.
Ecology: 25 m, on rocks.
Distribution: Iles des Glénans, S Bretagne, France.
Etymology: Albus (Latin) = white.
Type specimen information: No data, presumably the type is in the Iles de Glénan biological station.

Remarks

The encrusting habit and spiculation is unique among the Axinella species of the area. The spiculation and growth form resembles that of Axinella pyramidata , but no trichodragmas have been recorded from that species.
Source: Descatoire, 1966