ULTRASTRUCTURAL ASPECTS OF THE FEMALE GONAD OF TWO SYMBIOTIC FLATWORMS (PLATYHELMINTHES, TEMNOCEPHALIDA)

摘要

The female gonad of the temnocephalids examined displays some ultrastructural characteristics which differ from those typical of the taxon Rhabdocoela. They are: 1) the presence in the oocytes of inclusions with a glycoprotein content as is the case in other platyhelminths where such inclusions have been interpreted as cortical granules or yolk. This feature differs from that observed in all the other rhabdocoels studied so far where only egg granules with a granular content containing polyphenols, and interpreted as residual eggshell granules, have been found. 2) The presence in the vitellocytes of Troglocaridicola sp. of eggshell globules with a concentric polyphenolic content which does not correspond to the multigranular pattern typical of all the other Rhabdocoela. By contrast the peculiar design of the egeshell globules of Troglocaridicola sp. resembles that o fProseriata and tricladida. These data and of the close phylogenetic relationships between Scutariellidae and Temnocephalidae.