Polejaevia, Borojevic & Boury-Esnault & Vacelet, 2000

Borojevic, Radovan, Boury-Esnault, Nicole & Vacelet, Jean, 2000, A revision of the supraspecific classification of the subclass Calcaronea (Porifera, class Calcarea), Zoosystema 22 (2), pp. 203-263 : 232

Genus Polejaevia n. gen.

TYPE SPECIES. — Polejna telum Lendenfeld, 1891 by monotypy.

DIAGNOSIS. — Jenkinidae with a sylleibid organization. The cortex is supported by a layer of large tangential triactines. The choanoskeleton is composed of the unpaired actines of the subatrial triactines, and of rare small scattered triactines.

DESCRIPTION

In the system proposed by Lendenfeld (1891), the genus Polejna Lendenfeld, 1885 was used for sylleibid sponges with triactines and tetractines. The type species of Polejna , described originally as Leucilla uter Poléjaeff, 1884 is in fact a good species of Leucilla (Borojevic & Boury-Esnault 1987) . Polejna is thus a junior synonym of Leucilla . Subsequently, Lendenfeld (1891) described in Adriatic a new species in the genus, Polejna telum Lendenfeld, 1891 , that we consider to be different from Amphoriscidae and place now in the family Jenkinidae . A new name is thus required for the Jenkinidae with a sylleibid organization and triactines and tetractines such as Polejna telum , for which we propose Polejaevia .

The position of Polejaevia in the family Jenkinidae is somewhat dubious, since small choanosomal triactines have been described in it and are represented in the illustration of the type species, distinguishing it from typical Jenkinidae . The size and distribution of the triactines is quite unusual, and as they are not reminiscent of the articulate choanoskeleton of the tubes of the Grantiidae , classification of P. telum in the genus Leucandra is impossible. Lendenfeld (1891) suggested that the triactines might be young cortical triactines. Secondary spicules may be found in the choanosome in the absence of any other skeleton, as seen in the genus Leucettusa Haeckel, 1872 (Borojevic et al. 1990). On the other hand, the organization of Polejaevia can be understood to be quite similar to Anamixilla : while in the former the additional triactines in the choanosome are new spicules, in Anamixilla the cortical spicules apparently invade the choanoskeleton. We propose that the genus should be maintained in the Jenkinidae until new specimens are examined.

The description of Leucandra mawsoni Dendy, 1918 suggests that it might belong to Polejaevia . We have examined the specimens deposited in the British Museum (BMNH 20.12.9.95) and found that this species is a calcinean sponge, belonging to the genus Leucascus . Hence Polejaevia telum is the only known species belonging to this genus.