Spongia nitens

(Schmidt, 1862)

Species Overview

Spongia nitens (Schmidt, 1862) is a yellowish, white, massive-lobate sponge, of which the lobes may be prolonged and anastomosed. The lobes have a central canal which ends in an oscule. The consistency is spongy-compressible, elastic. It is a "bath sponge" of inferior quality and not exploited commercially. It is predominantly Mediterranean, but specimen have been recorded along the Atlantic coast of Portugal.

Taxonomic Description

Colour: Yellowish white.
Shape, size, surface and consistency: Massive-lobate, with lobes often prolonged and anastomosing. Size up to 7 x 6 x 4 cm. Surface finely conulose. Oscules on top of the lobes, which are frequently hollow; size of oscules 1-4 mm. Consistency spongy, compressible, elastic.
Spicules: Absent.
Skeleton: (Spongia nitens fibres) A reticulation of spongin fibres. At the surface there is a fine-meshed tangential reticulation of fibres with smaller meshes than those of the choanosome. Primary fibres of the choanosomal skeleton 20-90 µm, which are devoid of any inclusions, but have a distinct pith. They are only recognizable by their slightly thicker diameter, pith, and orientation. Secondary fibres lack a pith and are much thinner: 12-40 µm.
Ecology: In caves and under overhangs down to at least 25 m.
Distribution: Mid-Portugal; Mediterranean.
Etymology: Nitens (Latin) = shining bright or elegant, presumably referring to the surface which is light compared to other Spongia and has the fine-meshed network.
Type specimen information: Several type specimens are housed in Graz: LMJG 15401, 15471, 15472, 15403. Type slide: BMNH 1867.3.11.62 (Schmidt slide).

Remarks

This Spongia is easily recognizable by its fine-meshed surface reticulation, for which Schmidt (1868) erected a separated genus Ditela .
Source: Vacelet, 1959.