Digenetic trematodes of the Subfamily Aphanurinae Skrjabin & Guschanskaja, 1954 infecting the commercially important fish Thryssa malabarica (Bloch, 1795) (Clupeiformes, Engraulidae) from the brackishwater bodies of Kerala, India

Three species of digenetic trematodes of the Family Hemiuridae Looss, 1899, Subfamily Aphanurinae Skrjabin & Guschanskaja, 1954 with their prevalence, intensity of infection and mean abundance are reported Aphanuroides lethrini, Aphanurus stossichii and Aphanurus tuberculatus. A total of 26 specimens of Thryssa malabarica (Bloch, 1795) were examined for digenean infection. Prevalence of infection of A. lethrini, A. stossichii and A. tuberculatus were 11.53%, 69.23% and 15.38%, respectively, the intensity of infection were 1.6, 3.1 and 2.5 and the mean abundance were 0.19, 2.15 and 0.38, respectively. The prevalence, intensity and mean abundance of infection were at the maximum level in A. stossichii infection. Recovery of these parasites from T. malabarica represents a new host record and the first report from Kerala. The characteristic features of the recovered digeneans are discussed.