Amphinolana, Rützler & Hooper, 2000

Rützler, Klaus & Hooper, John N. A., 2000, Two new genera of hadromerid sponges (Porifera, Demospongiae), Zoosystema 22 (2), pp. 337-344 : 339

Genus Amphinolana n. gen.

TYPE SPECIES. — Amphinolana claudelevii n. sp.

ETYMOLOGY. — The name is composed of amphi- (Greek: double, on both sides) and nola f. (Latin: little bell) after the shape of the cortical spicules.

DIAGNOSIS. — Placospongiidae with dumbbell-like “amphisterrasters” forming the cortical plates and occurring densely scattered in the choanosome. The amphisterrasters have fused spines with free mammiform tips and a smooth or knobby shaft connecting the two heads; they are termed “amphinolasters”. Accessory spirasters are dispersed throughout the choanosome.

TAXONOMIC REMARKS

The principal difference between the two genera of Placospongiidae at our present stage of knowledge is the nature of the cortical microscleres, selenasters in Placospongia Gray, 1867 and amphinolasters in Amphinolana . Although both start out as spiny diactines, their transformation into mature spicules is substantially different and separation of the taxa at genus level is warranted for the evolutionary significance attributable to cortical spicules over regular microscleres. A comparable situation is found in the genera Spirastrella and Diplastrella Topsent, 1918 which are very similar in morphology and spiculation except that in the latter the spirasters are replaced by diplasters, an astrose microsclere in which the spines radiate from two slightly distant points.