Timea hallezi

(Topsent, 1894)

Species Overview

Timea hallezi (Topsent, 1894) is an ochre yellow, very thin, firm-tough encrustation under rocks in the sublittoral. It is rather rare, known only from the west coasts of Ireland, France and Belgium.

Taxonomic Description

Colour: Ochre yellow.
Shape, size, surface and consistency: Thinly encrusting, 0.5-0.7 mm in thickness. Surface uniform, without visibleaquiferous openings, slightly hispid. Consistency firm.
Spicules: Megascleres : Smooth tylostyles, straight or slightly curved, head elliptic or trilobate, not very strongly developed; length variable: 600-750 µm.
Microscleres : Spherasters with numerous (12-15) conical, finely spined rays, with a thick centre: 12-15 µm.
Skeleton: Bundles of tylostyles are erect on the substratum, heads downward, points protruding beyond the surface; thick layers of asters at the surface give the sponge a tough consistency.
Ecology: 20 m
Distribution: NW France (Le Portel, Luc, Roscoff), Belgium, W Ireland.
Etymology: The name refers to the spherasters.
Type specimen information: The type is in the Muséum National d'Histoire Naturelle, Paris.

Remarks: This species differs from the common T . stellata in the shape and the number of rays of the microscleres (T . stellata has smaller asters with 6-8 strongylote rays). T . unistellata has larger asters (25-30 µm) with smooth rays.
Source: Topsent, 1894.