Population dynamics of Piscicola Geometra (Hirudinea:Rhynchobdellida) on Oreochromis Niloticus (Cichlidae) cultured in a rainforest fish pond, South Eastern Nigeria

The distribution, abundance and intensity of the annelid worm, Piscicola geometra (leeches) infecting Oreochromis niloticus cultured in a rainforest fish pond, South Eastern Nigeria was studied over a 12 months period. Three hundred fish were examined of which 48.3% were infected. Infection occurred throughout the year, with a peak in February. Female fish had a significantly higher intensity of infection( P < 0.05) than males. There was a clear seasonal periodicity in the degree of infection and the distribution of the parasite exhibited an aggregated or contagious model of dispersion. There was a significant positive correlation between the size of the fish and worm burden.