Length-weight relationship and parasites of Chrysichthys nigrodigitatus in Cross River Estuary Itu local government area Akwa Ibom State, Nigeria

The study describes the length-weight relationship and helminthes bioload of Chrysichthys nigrodigitatus (Catfish) in the Cross river estuary purchased at Ayaedehe, Itu Local Government Area, Akwa Ibom State. A total of four hundred and twenty (420) life specimens of C. nigrodigitatus were collected by local fishing gear between June and November, 2011. Data obtained were statistically analyzed using descriptive and inferential statistics. Results showed that the highest length was obtained in July (100.2cm) while the least was obtained in June (15.30cm). The highest weight was 1410g obtained in October while the least was obtained in September (22.10g) and there were significant differences in monthly distribution of length and weight (P<0.05) of the specimens. Correction coefficient (r) between length and weight of C. nigrodigitatus from June November, 2011 lied between 0.89 and 0.98 representing strong relationship between length and weight, the relationship was found to be linear but in logarithmic form. Generally condition factor, (K) values decreased proportionately with the length of the fish. A total of seventy two (72) (17.14%) parasite specimens were recovered from the fish, out of which helminthes parasites include a cestode Proteocephalis 9 (12.5%) and aspidogastrid trematode, Aspidogastrea africanus 10 (13.89%) and Nematodes; Paracamallanus cyathopharynx 34 (47.22%) and Contracacum sp. 19 (26.64%). Parasitic worm burden and Intensity of infection low and independent of length and weight.