The alleged alternation of sexual phases inKuhnia scombri, a monogenean ofScomber scombrus

Abstract

SUMMARYIn 1945 Sproston stated that an alternation of sexual phases takes place inKuhnia scombri, a monogenean ofScomber scombrus, but an examination of egg-laying, the state of the sexual organs and the presence of sperms in this parasite at various times of the year have shown that there is no evidence for the existence of such a phenomenon. Sproston's observations are examined with particular reference to problems in measuring the length of the parasite and to the unreliability of using the presence or absence of eggs in the uterus as an index of femaleness.