Timea mixta

(Topsent, 1896)

Species Overview

Timea mixta (Topsent, 1896) is a thin yellow encrusting sponge with a hispid surface. It is a southern species recorded once from Roscoff.

Taxonomic Description

Colour: Yellow-ochre.
Shape, size, surface and consistency: Thinly encrusting, hispid surface. No visible oscules.
Spicules: Megascleres : Tylostyles, smooth, straight or slightly curved, finely pointed, with lobed or elliptical tyle, in a long size range: 275-1000 x 9 µm.
Microscleres : Spherasters in two categories, larger ones which are more numerous, with 10-12 conical rays, either completely smooth or slightly spined: 15-35 µm in diameter, the smaller ones are 5-6 µm in diameter, with 6-8 truncated rays.
Skeleton: Tylostyles are all erect on the substrate, singly, not in bundles, heads down, the longer protrude beyond the surface. The smaller spherasters accumulate at the surface, the larger ones are found in the interior.
Ecology: 30-60 m
Distribution: Mediterranean, Roscoff.
Etymology: The name refers to the diversity of asters.
Type specimen information: The type is in the Muséum National d'Histoire Naturelle, Paris.

Remarks

This species differs from the other Timea species of the area in the differentiation of the spherasters into larger ones with conical rays and smaller with truncated rays.
Source: Topsent, 1900.