(Vosmaer, 1885)
Species Overview
Stryphnus ponderosus (Vosmaer, 1885) is a globular-massive to lumpy sponge with very rough surface (if touched with the naked hand large numbers of spicules will penetrate the skin). Colour is red-brown. It is a northern deep water species.
Taxonomic Description
Colour: Brownish red on the outside, ochre-yellow on the inside.
Shape, size, surface and consistency: Globular-massive or lumpy. Size up to 15 cm or more in diameter and height. Surface extremely rough, hispid, with spicules sticking out far beyond the surface, but otherwise even. The inner parts look like"dry old bread". Consistency hard, crumbly.
Spicules: (Stryphnus fortis spics) Megascleres : oxeas, 1700-2000 x 50-80 µm; plagiotriaenes with rhabd: 600-900 x 50-80 µm, cladi: 300-500 µm, cladome: 500-750 µm.
Microscleres : Amphiasters, with short irregular rays, almost spiraster-like: 10-12 µm; oxyasters with 6-8 rays (mostly 6 rays): 30-70 µm in diameter.
Skeleton: The plagiotraenes are arranged near the surface and carry the cortex charged with amphiasters; oxeas are intermingled with the plagiotriaenes and protrude far beyond the surface. In the interior oxeas are confusedly distributed and oxyasters are concentrated there.
Ecology: Deep water, 62-1384 m.
Distribution: Norway, Arctic.
Etymology: Fortis (Latin) = strong.
Type specimen information: Two type specimens are in the Zoological Museum Amsterdam: ZMA POR. 2189 and 2190.
Remarks
A second species of Stryphnus , S . ponderosus may occur in the same area as the present species. They are readily distinguished by the occurrence of dichotriaenes in S . ponderosus . Koltun (1966) considers both synonymous.
Source: Vosmaer, 1885.