Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from Raja naevus with a comment on its habitat and mode of attachment

Abstract

Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from the intestine of Raja naevus in the North Sea resembles P. dagnallium, P. radioductum and P. britannicum more closely than any other known species of the genus but differs from these mainly in its host, in having distinctly bifid bothridia with faint marginal loculi and about 150 testes in each proglottid. Brief comments are made on the preference shown by the adult for the posterior region of the intestine and on a modification of its bothridium for attachment to up to 12 villi.This work was supported by generous financial aid from the Natural Environment Research Council. I wish also to record my gratitude to Professor V. C. Wynne-Edwards and Dr P. A. Orkin for reading and suggesting improvements to the manuscript and to the Director and staff Marine Laboratory, Aberdeen, in particular Dr B. B. Rae and Mr Stuart Pirie, after whom this species has been named, for providing live rays. Alasdair McVivar of this department, who has now begun an independent study of the intestine of Raja naevus as a habitat for helminth parasites, kindly provided information for Fig. 9.