Marine Species Identification Portal : Ircinia variabilis

(Schmidt, 1862)

Species Overview

Ircinia variabilis (Schmidt, 1862) is a variable, massive, or thickly encrusting conulose sponge. Colour variably whitish to pink, greenish to even blackish. It is a southern species recorded a few times from the Atlantic coasts of Portugal and Spain.

Taxonomic Description

Colour: Very variable: Grey, greenish maroon, whitish, violet.
Shape, size, surface and consistency: (Ircinia fasciculata Carballo) Very variable, encrusting, massive, with projections. Size up to 70 cm in lateral expansion, 20 cm thick, but normally much smaller. Conules variable in height, up to 3 mm, and spacing. Oscules up to 8 mm in diameter, distributed irregularly. Consistency firmly compressible, difficult to cut or tear.
Spicules: Absent.
Skeleton: The ectosome is strengthened by sand grains, which form a coat over the surface, may form a reticulation or may be absent locally. The choanosomal skeleton consists of a system of primary fibres of 100-250 µm in diameter, always cored by sand grains and other foreign material, and secondary fibres, thinner: 40-70 µm, mostly devoid of inclusions. Filaments are numerous and have a diameter of 2-8 µm, with oval terminal knobs of 5-11 µm.
Ecology: From the low water mark downwards to at least 150 m; common on vertical cliffs between 7 and 25 m
Distribution: Portugal, Galicia; Mediterranean.
Etymology: The name refers to the great variability in shapes.
Type specimen information: Type probably lost.

Remarks

This species could be confused with the other massive Ircinid species (e.g. Sarcotragus) from the area, but the thickness of the filaments (less than 2 µm in the latter two species) and the fibres (uncored in Sarcotragus species) makes distinction easy.
Source: Vacelet, 1959.

Ircinia variabilis