Rapp, Klautau & Valentine, 2001
Clathrina septentrionalis Rapp et al. (2001) was recently described based on old preserved material. It is a massive sponge consisting of a reticulation of thin tubes. Spicules include both triactines and tetractines, the latter with a shorter apical actine.
Shape: Cormus of this massive sponge formed of thin, irregular and tightly anastomosed tubes. Watercollecting tubes converge at conical elevations with a terminal osculum.
Spicules: Triactines, rays 95-135 x 10 µm and tetractines, rays 97-125 x 10 µm, apical actines 52-87 x 4.5 µm. Actines are cylindrical, slightly undulated, with a blunt tip. The apical actine of the tetractines is shorter than the facial ones, cylindrical, smooth, sharp and curved at the tip.
Skeleton: The skeleton has no special organization, comprising equiangular and equiradiate triactines and tetractines.
Cell biology: Cells with brown granules are scattered in the mesohyl.
Distribution: Langfjorden, Norway.
Type: BMNH 1910.1.1.790 (holotype/alcohol). Langfjorden, Norway. Stn. 76.5 fms. Canon A.M. Norman Collection; BMNH 1910.1.1.789 (paratype/alcohol).
Clathrina contorta has similar spiculation but much thicker tubes and the apical actines of the tetractines are shorter (45 µm). C. cerebrum is stalked and has the apical ray of the tetractines longer and spined.
In many characteristics, the morphology of C. septentrionalis matches that of Leucosolenia nanseni Breitfuss, 1896, a sponge from East Spitzbergen. As the holotype or a paratype of this species could not be found, only the written information given in Breitfuss' description and plates is available, which created difficulties in deciding if C. septentrionalis should be a synonym of L. nanseni or not.
Source: Klautau & Valentine, 2003