Population dynamics of cestode, Circumonchobothrium shindei (Cestoda: Pseudophyllidea Carus, 1863) in the freshwater eel, Mastacembelus armatus Lacépède, 1800 from River Godavari, Rajahmundry

The freshwater eel, Mastacembelus armatus Lacépède, 1800 is often found infected with adults and larval plerocercoids of the cestode, Circumonchobothrium shindei. The population dynamics of C. shindei was studied in the freshwater eel, M. armatus during September 2005 to August 2007 from Godavari River, Rajahmundry. A total of 494 eels were examined; 184 (37.24 %) were infected with this cestode. Infection intensity ranged from 1 to 13 for C. shindei and their plerocercoids. C. shindei occupy the position of secondary species in community structure of metazoan parasites of M. armatus, with mean intensity, mean abundance and index of infection (2.5 ± 1.22; 1.1 ± 1.45 and 0.57 respectively). The present investigation deals with monthly population dynamics of C. shindei in M. armatus which summarizes percentage of prevalence, intensity, abundance and index of infection. Medium sized fish depicted more infection with this cestode and female fish illustrates comparatively higher infection rate than male fish.