On the Validity of an Eel Monogenean Pseudodactylogyrus Microrchis Ogawa et Egusa, 1976

Abstract

Reconsideration is given to the validity of Pseudodactylogyrus microrchis OGAWA et EGUSA, 1976, based on the specimens freshly collected from cultured eel (Anguilla japonica and A. anguilla) in five different localities in Japan and in Taiwan as well as the type specimens of P. microrchis. Unlike the case of the type specimens, the testis is very large, sometimes well over 0.1 mm in dia meter and larger than the ovary, in some freshly collected P. microrchis specimens. It was very difficult to separate them from most related species, P. anguillae, by the size of the testis and the size ratio of the testis to the ovary, formerly the most reliable criteria on which to differentiate the two species. It is, thus, concluded that P. microrchis should be synonymized with P. anguillae by Law of Priority. © 1985, The Japanese Society of Fisheries Science. All rights reserved.