Axinella pyramidata

Stephens, 1916

Species Overview

Axinella pyramidata Stephens, 1916 is a short-stalked flattened Axinella reported from deeper water off the west coasts of Ireland and France. It is ill-known and may turn out to be conspecific with A . damicornis .

Taxonomic Description

Colour: No data.
Shape, size, surface and consistency: In shape it somewhat like a three-sided pyramid standing on its apex, except that the sides are deeply cut vertically into a series of flattened lobes. The upper surface is flat, but here and there it rises into small knob-like elevations. Height 15 mm, diameter 17 mm.
Spicules: (Axinella pyramidata spics) Styles variable: about 230-1000 x 10-16 µm; in the shorter styles the shaft is rather sharply bent at a little distance above the head; the longer styles are usually slightly curved; there is sometimes a slight swelling on the shaft a little distance above the head. Oxeas: 300-600 x 10-13 µm; they are sharply and irregularly bent and taper at either end to a rather sharp point; many of the oxeas have a slight swelling about the middle of the spicule.
Skeleton: This consists of closely set plumose columns of spicules which run upwards through the sponge, and then bend out towards the surface, where they end in brushes of styles which project for part of their length beyond the surface; a considerable amount of spongin is present, cementing the spicules together.
Ecology: 65-99 m.
Distribution: Off SW Ireland, Faroes, Roscoff; ?West Africa.
Etymology: The name refers to the shape.
Type specimen information: No data; the type presumably is in the National Museum of Ireland, Dublin.

Remarks

Spiculation is similar to Axinella damicornis and that species may form rather squat individuals which approach A . pyramidata in form. The type needs to be re-examined and compared with A . damicornis .
The specimen recorded from West Africa (Burton, 1956) (Axinella pyramidata Burton) may not be conspecific with Stephens' specimen.
Source: Stephens, 1916