Dysidea avara

(Schmidt, 1862)

Species Overview

Dysidea avara (Schmidt, 1862) is a rosy to violet, massive, conulose, soft sponge. It is a Mediterranean species, similar to the common Dysidea fragilis , but with a coarser surface, with higher conules, placed further apart. It has been recorded from various localities along the coasts of Western Europe, but only the southern records (Galicia) appear to be certain.

Taxonomic Description

Colour: Soft rosy to dark maroon or violet; when put in alcohol this is strongly discoloured.
Shape, size, surface and consistency: Massive, occasionally somewhat lobate. Size up to 25 x 15 x 5 cm. Surface strongly conulose, conules up to 4 mm high and 2-5 mm apart. The conules have a strongly reticulate appearance. Oscules at the summit lobes, 1-3 mm in diameter. Consistency soft.
Spicules: Absent.
Skeleton: A reticulation of spongin fibres filled with sand grains. Primary fibres always filled, secondary fibres may be sometimes completely free. Primary fibres 150-350 µm in diameter, secondary fibres 60-140 µm.
Reproduction: In the Mediterranean embryos are found in June.
Ecology: In caves and on vertical cliffs, from 1 m downwards (to at least 100 m).
Distribution: Galicia; Mediterranean.
Etymology: Avarus (Latin) = greedy, possibly referring to the large amount of sand grains it has taken up.
Type specimen information: Dry type specimens are present in the Graz Museum, LMJG 15391 and 15388. 2 dry specimens (under Spongelia ) in London: BMNH 1867.7.26.82 and 1867.7.26.96 purchased of O. Schmidt, from Sebenico.

Remarks

This species is very similar to Dysidea fragilis . The differences may be listed as follows: D . avara is more intensely coloured, often darker; the conules are much higher and further apart. The skeleton is more open-meshed and primary fibres are thicker. An absolute difference is not apparent, but when both species occur together (Mediterranean), the differences are clear.
Source: Carballo et al., 1994