Home|Search|Identify|Taxonomic tree|Quiz|About this site|Feedback
Developed by ETI BioInformatics
Characteristics, distribution and ecology
Taxonomische classification
Synonyms and common names
Literature references
Images, audio and video
Links to other Web sites

(Bowerbank, 1874)

Species Overview

Hamacantha (Vomerula) falcula (Bowerbank, 1874) is an irregularly lobate, cushion-shaped sponge with a detachable skin. The oscules are slightly raised on low conules. Live colour has not been recorded. It is a deep-water sponge. The genus Hamacantha has characteristic microscleres (diancistras); the present species may be distinguished from the two other Hamacantha species from the area by its possession of toxas.

Taxonomic Description

Colour: Live colour unknown; yellow to white in alcohol.
Shape, size, surface and consistency: Massive, irregularly lobate, roundish. Size up to 9.5 cm in lateral expansion. Surface smooth, with detachable "skin". Oscules on low conules of several mm high. Consistency rather firm.
Spicules: (Hamacantha falcula spics) Megascleres: Styles 340-470 x 5-8 µm. Microscleres: Diancistras in three categories: 100-178 µm, 30-57 µm and 18-28 µm; toxas 60-157 µm.
Skeleton: Ectosomal skeleton a tangential reticulation of spicule tracts. Choanosomal skeleton plumose, with spicule bundles running to the surface where they fan out.
Ecology: Deep water: 85-2280 m
Distribution: Roscoff, W Ireland, Scotland, Sweden, Norway, Faroes, Iceland; also Madeira and Azores.
Etymology: falcula (Latin) = small sickle, referring to the shape of the microscleres.
Type specimen information: The type is in the Natural History Museum, London: Type: BMNH 1910.1.1.191 (dry). Norman Collection.

Remarks

Hamacantha with its characteristic diancistras is represented by three species in the area. H. (H.) johnsoni has oxeas for megascleres and true sigmas; H. (H.) papillata (=H. implicans) has trichodragmas and only a single category of diancistras. Both species lack the toxas of H. (V.) falcula.
Source: Arndt, 1935.

Hamacantha falcula