Haeckel, 1870
Species Overview
Ascaltis lamarcki Haeckel, 1870 is a small fragile, whitish or reddish rounded mass of anastomosing tubes with an apical oscule. There is a resemblance with certain Clathrina , but in contrast with species of that genus, there is a "skin" covering the mass of tubes. Also, in this species, large spicules may be visible at the surface. It has a wide distribution along most of the coasts of Western Europe, but is not recorded often as it ocurs below 60 m.
Taxonomic Description
Colour: Whitish or pale red.
Shape size, surface and consistency: Transparent strawberry-like rounded mass of anastomosing and ramified tubes covered by a continuous "skin". Small size, up to 4 cm in height and diameter, often smaller. Surface perforated by ostioles which open into the aquiferous system. Consistency fragile.
Spicules: (A. lamarcki Burton) Calcareous. Triactines and (rudimentary) tetractines.
Regular triactines of the cortex large, equiangular and equiradiate: 338-377 x 26-31 µm. Regular triactines of the choanosomal skeleton: with rays 80-130 x 2-10 µm.
Regular tetractines, which are triactines with a rudimentary fourth ray: normal rays 80-120 x 4-6 µm.
Skeleton: There is a cortical skeleton consisting of tri-and tetractines, while the choanosomal skeleton consists of triactines only. The tubes forming the choanocyte chambers are peripherally branched (Ascaltis lamarcki anat).
Reproduction: August-September.
Ecology: On hard substrates, in deeper water, 60-645 m.
Distribution: Arctic, W-coast of France, Bay of Biscay; Gibraltar, Morocco; elsewhere reported from Australia and Florida.
Etymology: Named after the distinguished naturalist Jean Baptiste de Lamarck, pioneering author of sponge systematics.
Type specimen information: No type material in BMNH; type probably lost.
Remarks
This is an ill-known species and more information on its distribution is required. The records from other parts of the world need comparison.
There is a nomenclatorial problem with the present species: recent revision (Borojevic et al., 1990) ignored Dendy and Row's (1913) conclusion that lamarcki is a junior synonym of Aulorrhiza intestinalis Haeckel, 1869 (1872). It is here proposed to follow the recent revision (but see Hooper and Wiedenmayer, 1994).
Sources: Borojevic, 1968; Borojevic et al., 1990.