(Schmidt, 1862)
Species Overview
Cliona viridis (Schmidt, 1862) is an excavating sponge, recognizable as papillae sticking out of calcareous substrates, or covering a massive surface which has completely overgrown and eroded the substrate; it is easily distinguished from the rather similar yellow Cliona celata by having a green colour. It is a southern species.
Taxonomic Description
Colour: Green, lighter or darker, may be yellowish green.
Shape, size, surface and consistency: Excavating. Occurring mostly in the overgrowth stage or the massive stage, in which the substrate has been eroded away (Cliona viridis Vosmaer). Excavated galleries may be of variable size 0.3-2.5 mm in diameter. Papillae of the alpha stage are relatively widely spaced and large, up to 2-3 mm in diameter. In the gamma-stage it is globular, up to 15 cm in diameter. The surface is optically smooth, and papillae may be up to 8 mm in diameter and up to 15 mm high (Cliona viridis close up). The consistency is tough, almost hard.
Spicules: Megascleres : Tylostyles, smooth, straight or slightly curved, fusiform, with elongate well-developed tyle and relatively abrupt point: 400-550 x 10-12 µm. Microscleres : (Cliona viridis microscleres) Spirasters, long and thin, with 2-5 sinuous curves, and small spines: 15-40 x 0.5-2 µm.
Skeleton: Ectosomal : a palisade of spicules is found at the surface of papillae and encrusting or massive specimens. Chonaosomal : these palisades or bouquets are carried by thick spicule bundles which form an irregularly plumose anastomosing system in the more massive parts. Spirasters are not abundant, and are lacking in the papillae and in the peripheral parts. In gamma stage specimens they are rare.
Ecology: In or on calcareous substrate, in shallow water.
Distribution: NW Spain, Mediterranean; Burton (1930) recorded this species from Norway, but that needs confirmation.
Type specimen information: The type is in the Graz Museum, No. LMJG15652, from Zara, Adriatic (cf. Desqueyroux-Faúndez and Stone, 1992)
Remarks
This species may be easily distinguished from Cliona celata by its colour and possession of microscleres.
Source: Topsent, 1900.