Haliotrema Kurodai n. sp. (Monogenea: Dactylogyridae, Ancyrocephalinae), a Monogenean Parasite Obtained from the Japanese Black Sea Bream, Acanthopagrus schlegeli (BLEEKER)

Abstract

A description is given of Haliotrema kurodain. sp., a monogenean parasite from the gill filament of the Japanese black esa bream, Acanthopagrus schlegeli, cultured in aquaria in Shizuoka and Hiroshima Prefs., Japan. This is the first recorded case of Haliotrema from fish belonging to the family Sparidae.
Morphologically, this species is most characterized by the presence of four conspicuous reserviors of the cement glands. It should also be noted that the number of the marginal hooks are twelve, which seems to be an exceptional case in the genus.
Haliotrema kurodai n. sp. is very similar to YOUNG's species group 6, from which it differs in the absence of posterior diverticula of the intestine and in the number of the marginal hooks. This species may rather bear a closer resemblance to Placodiscus acanthopagri PAPERNA, 1972 in morphology and the host species, but may be discriminated from the latter species by the shape and size of the two anchor complexes. The difference remains unclarified of the nature of the cement reservoirs of Haliotrema species including H. kurodai. Further examination of the validity of the genus Placodiscus is needed.