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Direct Research Journals
Direct Research Journal of Agriculture and Food Science (DRJAFS) Vol.3 (11), pp. 193-205, November 2015
ISSN: 2354-4147

Studies on the aspect of the biology of Mochokidae in the lower Cross River, Akwa Ibom State, Nigeria
Article Number: DRJA17085244
DOI:

Original Research Article


ESSIEN-IBOK, M. A., EKPO, I. E.* and BASSEY, H. E.


Department of Fisheries and Aquatic Environmental Management, University of Uyo, P. M. B 1017, Uyo – 520001, Akwa Ibom State, Nigeria.


date Received: October 3, 2015     date Accepted: November 4, 2015     date Published: November 14, 2015

Abstract

Some aspects of the biology of Mochokidae in the artisanal fishers’ landings in the lower Cross River, Nigeria were studied between May and December, 2014. A total of 360 specimens comprising 3 genera and 14 species with 6-29.50 cm total length (mean: 12.80 cm TL) and 0.16-268.21 g total weight (mean: 30.65 g TW) were examined. The largest sample size was recorded in Synodontis schall (61 specimens; 16.94%) while Mochokus niloticus and S. clarias with one specimen (0.28%) were the least. The degree of effective contribution expressed as index of preponderance revealed that S. schall (33.63%) made the most significant contribution while S. waterlofti (0.06%) made the least contribution. Length-weight relationship showed that the growth pattern of the fishes were negatively allometric with the slope, b values’ ranges of 1.36 and 2.02 for Synodontis omias and S. waterlofti (P<0.05). Gut contents revealed that 11 food items were ingested (sediments, detritus, insect, algae, macrophytes, crustaceans, annelids, molluscs, nematodes and unidentified food); hence they were euryphagus. The present study revealed that Mochokidae is an omnivore-detritivore with highest body condition factor of  (1.46) for  S. obesus and lowest (0.96) for C. batesii; with mean K value of 1.23. This implies that could thrive better even when environmental factors are less favorable; hence, they are recommended for aquaculture.


Key words: Biology, body condition, gut contents, length-weight relationship, lower Cross River and Mochokidae.