Studies on Penetrocephalus ganapatii, a new genus (Cestoda: Pseudophyllidea) from the marine teleost Saurida tumbil (Bloch).

Abstract

1. The character of the scolex, the long filamentous neck and the morphology of the proglottids are features which justify the establishment of a new genus,Penetrocephalus,to accommodate the pseudophyllid speciesP. ganapatii(=Both-riocephalus ganapatii(Rao, 1954),B. penetratus(Subhapradha, 1955)) from the marine teleostSaurida tumbilBloch, off Waltair, Bay of Bengal.2. The anatomy of the female reproductive system is described in detail, and a preliminary interpretation of the histochemistry of egg-shell formation is given.3. On the basis of histochemical tests it is suggested that Mehlis's gland, which surrounds the cellular ootype, secretes a phospholipid-like material which may aid in the release of shell precursors from the vitelline cells, but it does not form part of the shell. It appears also to be responsible for the synthesis of PAS-positive yolky matter found in these cells in the egg capsule. The functions of Mehlis's gland in helminths are discussed.4. In a majority of helminths where the egg-shell is a quinone-tanned protein, it is considered that it is solely if not entirely derived from shell globules in the vitelline cells.