Clathria (Microciona) macrochela (Lévi, 1960) is one of many encrusting Microcionidae which are indistinguishable in the field. Microscopic examination is necessary. The distinctive feature of this sponge is its relatively large palmate isochelae (30 µm). It is so far known only from a single record off the coast of Bretagne, France.
Colour: No data available (presumably red or orange).
Shape, size, surface and consistency: Extremely thinly encrusting.
Spicules: Megascleres: Ectosomal subtylostyles with smooth heads or with some rudimentary spines: 200-325 µm; choanosomal acanthostyles with a smooth shaft and prominent spined head: 250-450 µm; echinating acanthostyles entirely spined, curved in the basal part, spines on the head blunt-cylindrical (in stead of pointed): 95-130 µm. Microscleres: Palmate isochelas, numerous, large: 30 µm; toxas, deeply curved, slightly rugose apices: 75-175 µm.
Skeleton: Leptoclathriid (=hymedesmoid), i.e. megascleres singly erect on the substrate.
Ecology: Deep water (15-60 m), on calcareous pebbles.
Distribution: Known only from Bretagne, France.
Type specimen information: The type is in the Muséum National d'Histoire Naturelle, Paris.
This species approaches Clathria (Clathria) anchorata (Carter, 1876), described from deep-water (below 450 m) off the coasts of W Europe, in the size of the chelae, but this is a massive species that lacks toxas and the sizes of the megascleres are also different.
Source: Lévi, 1960.