Geodia barretti

Bowerbank, 1858

Species Overview

Geodia barretti Bowerbank, 1858 is a large globular smooth sponge with a hard consistency. It is cream yellow and normally has one or several deep-sunken openings, which contain groups of exhalant oscules. It is a northern deep-water species, especially common in the Scandinavian fjord areas.

Taxonomic Description

Colour: Cream-yellow; pale yellow-white.
Shape, size, surface and consistency: Globular, larger specimens become irregular with one or more "sunken" oscules, which are in fact cavities in which grouped oscules are found. Size may be up to 50 cm or more. Surface smooth slightly undulate. Consistency hard.
Spicules: Megascleres : Oxeas of the radiate skeleton: up to 3600 x 70 µm; smaller oxeas of the cortex: up to 400 x 10 µm; dichotriaenes: up to 4000 x 100, protoclads up to 300 µm, deuteroclads up to 300 µm; protriaenes rare, but may be present; anatriaenes: up to 4500 x 15 µm, clads up to 170 µm.
Microscleres : Sterrasters, spherical up to 95 µm; spherasters with rounded rays: 8 µm; oxyasters, with spined rays: up to 50 µm.
Skeleton: (Geodia barretti skeleton) Radiate. Cortex about 0.5 mm thick, sterrastral layer about 300 µm; choanosomal skeleton confused.
Ecology: Deeper water, 15-329 m.
Distribution: Arctic, Norway, Sweden, North Atlantic.
Etymology: Named after its collector.
Type specimen information: BMNH specimen not registered (dry). From Vigten Id. Bowerbank Collection + slides: Unregistered (Bk. 1399, Bk.1400, Bk.1401).

Remarks

The large size, cream colour, and smooth globular habit make this species easy to recognize. It may be confused with Geodia cydonium , likewise a big cream coloured Geodia . This, however, lacks dichotriaenes, in stead of which there are orthotriaenes.
Source: Sollas, 1880, 1888.