(Schmidt, 1864)
Species Overview
Dictyonella pelligera (Schmidt, 1864) is a yellow-orange massive-lobate soft sponge with strongly conulose surface. It is a Mediterranean species recorded once in the Roscoff area, NW France.
Taxonomic Description
Colour: Ochre-beige or orange-pink.
Shape, size, surface and consistency: Massively lobate to lowly ramose with relatively thin, erect, irregular lobes/branches. Size up to 4 cm high, lobes/branches up to 1 cm in diameter. Surface strongly conulose caused by projecting spicule tracts. Oscules not apparent. Consistency soft, compressible.
Spicules: (Dictyonella pelligera spics) Styles, often with telescoped ends, curved: 440-700 x 3-10 µm.
Skeleton: Dendritic spongin-encased spicule tracts fan out towards the surface, where they end in the surface conules.
Reproduction: August to September (Mediterranean).
Ecology: On stones at 75 m (Roscoff), on rock faces at 25-35 m, in caves in more shallow depths (Mediterranean).
Distribution: Roscoff; Mediterranean.
Etymology: Pelliger = having a skin, referring to the organic skin stretched over the endings of the choanosomal spicule tracts.
Type specimen information: The type specimens are in the Graz Museum, LMJG 15514 and 15517. Type slide under Clathria in London: BMNH: 1867.3.11.29.
Remarks
Several closely similar species occur in the Mediterranean (D . incisa Schmidt, 1868, D . marsilii Topsent, 1938, D . alonsoi Carballo et al., 1996), discriminated mostly on the basis of spicule sizes. In the study area, the only closely related species is D . madeirensis (Topsent, 1928) recorded likewise once from Roscoff. It differs from D . pelligera in the more anastomosed skeletal tracts and the much thicker styles (up to 30 µm).
D . pelligera shares a feature with the Mediterranean Scopalina lophyropoda , viz. the granulated surface membrane, and it is not entirely impossible that pelligera fits better in Scopalina . This matter is left for a future revision of Mediterranean-Atlantic Dictyonellidae.
Source: Topsent, 1925a.