Sarcotragus muscarum

Schmidt, 1864

Species Overview

Sarcotragus muscarum Schmidt, 1864 is a large, massive, red-brown or marooon sponge with irregular coarsely conulose surface. The small oscules may have a transparent rim. It is a southern species recorded from the NW coast of Spain.

Taxonomic Description

Colour: Red-brown, maroon, yellowish or even blackish, typically variously tinted in the same individual.
Shape, size, surface and consistency: Irregularly massive, up to 15 cm thick and 50 cm or more across, but usually much smaller. Surface coarsely conulose, with conules 1.5-3 mm high, spaced 2-15 mm apart. Oscules small, 1-1.5 mm in diameter, often provided with a transparent rim. Consistency firmly compressible, resistant to tearing or cutting.
Spicules: Absent.
Skeleton: (Sarcotragus muscarum fib) The ectosome is a tough thick epidermis charged with a reticulation of sand grains. The choanosomal skeleton is a system of primary and secondary fibres, which are free from foreign inclusions, but have a distinct pith in primary fibres, mostly transparent in transmitted light. Primary fibres 80-150 µm in diameter. Secondary fibres, sometimes forming perforated spongin sheets, are 35-90 µm. Filaments are extremely fine and numerous: 0.8-2.3 µm
Reproduction: September-November (Carballo et al., 1994).
Ecology: Rocky substrate, from the tide mark down to 400 m.
Distribution: Galicia, Mediterranean, West Africa.
Etymology: Musca (Latin) = fly, presumably material of this sponge when brought above water attracts flies.
Type specimen information: Type specimens are in the Graz Museum, LMJG 15480, 15417 and 15484.

Remarks

This species is close to S . spinosula but differs in the much coarser conules and more irregular shape. Usually, S . spinosula is darker coloured.
Source: Vacelet (1959).