Three species of Heteromazocraes Mamaev, 1981 (Monogenea: Mazocraeidae), including two new species from Thryssa spp. (Teleostei: Engraulidae) off Visakhapatnam coast, Bay of Bengal.

Three species of Heteromazocraes Mamaev, 1981 including two new taxa are described from the gills of three species of engraulid fishes Thryssa mystax (Bloch & Schneider), T. setirostris (Broussonet) and T. malabarica (Bloch) collected from the coastal waters off Visakhapatnam, Bay of Bengal. Heteromazocraes thryssaensis n. sp. differs from the closely related H. dodecacantha Mamaev, 1981 in the shape of the body and ovary, the number of testes and the number and shape of the genital hooks. Heteromazocraes engrauliae n. sp. differs from all the other species of the genus in the relative sizes of the haptoral clamps, in that the four closed clamps on the left side are larger than the two open clamps on the right side, in contrast to the situation in other species where the two open clamps on the anterior right side are markedly larger than the remaining clamps. Heteromazocraes kazikodiensis (Gupta & Khullar, 1967) Mamaev, 1981 regarded as a species inquirenda is redescribed with additional details and is reinstated as a valid species. A review of Heteromazocraes including a key for identification of the species is provided.