Spongia officinalis

Linnaeus, 1759

Species Overview

Spongia officinalis Linnaeus, 1759 is a dark coloured, finely conulose, globular sponge which is very compressible, spongy, elastic. Internally, it is light-coloured. It usually has several oscules on the upper side. It has no spicules, just a jumbled network of yellow spongin fibres. It is a Mediterranean species, recorded also a few times along the Atlantic coasts of Spain.

Taxonomic Description

Colour: All intermediates between black and white, darker when exposed to direct light, light when growing in the dark.
Shape, size, surface and consistency: (Spongia officinalis large) Globular-massive, quite variable in shape. Size frequently over 10 cm in diameter. Surface quite regular, covered with fine conules of 0.2-0.5 mm high, spaced 1.5-2 mm apart. Oscules few in number, on the upper side, up to 1 cm in diameter. Consistency spongy-elastic, compressible, supple.
Spicules: Absent.
Skeleton: (Spongia officinalis fibres) A system of primary fibres cored by foreign material and uncored secondary fibres.The primary fibres are relatively rare, not differing from the secondary fibres in size, only recognizable by the core of spicule debris and small sand grains. Secondary fibres yellow-brown, 10-35 µm in diameter, and quite irregular in the way they anastomose. In general the reticulation is very dense and meshes are small and irregular.
Choaonocyte chambers: Spherical: 20-30 µm in diameter.
Ecology: On rocks and in caves, sublittoral.
Distribution: Galicia; Mediterranean.
Etymology: Officinalis (Latin) = useful for medicinal purpose.
Type specimen information: No type material in BMNH.

Remarks

This is the finest quality bath sponge in Europe, distinguished from the other species in globular-compact form.
Source: Vacelet, 1959.