Esperiopsis villosa

(Carter, 1874b)

Species Overview

Esperiopsis villosa (Carter, 1874b) is a massive lobate northern deep-water sponge, which has been recorded only a few times, and only once from shallow-water. It differs from other Esperiopsis species in possessing very large sigmas (microscopic examination). Its live colour is unknown.

Taxonomic Description

Colour: Grey in the dry state.
Shape, size, surface and consistency: Massive, lobular, erect. Size up to 6 x 3 x 2.5 cm. Surface villous, due to spicules tufts protruding beyond the skin. Oscules scattered here and there irregularly. Consistency fibrous.
Spicules: (Esperiopsis villosa spics) Megascleres : Styles with constricted necks: 590 x 4-5 µm. Microscleres : Palmate isochelae, in two categories: long and narrow, with recurved alae: 100 µm, and short and wide: ca. 60 µm; giant sigmas 160-170 µm.
Skeleton: A reticulation of strongly developed multispicular fibres with some loose spicules in the interstices. Surface skeleton a crust of tangential megascleres.
Ecology: 36-2000 m
Distribution: Norway, Scotland, Faroes.
Etymology: The name refers to the hairy condition of the surface.
Type specimen information: The type is in the Natural History Museum, London: BMNH 1882.7.28.55A (Esperiopsis villosa Carter).

Remarks

This species is ill-known and possibly not congeneric with both other Esperiopsis species. The possession of sigmas is shared with a fourth Esperiopsis , viz. E . schmidti (Arnesen, 1903) known only from 500 m depth. Both sigma-bearing species are dubious Esperiopsis , but until further studies they are retained here.
Source: Carter, 1874b.