Length frequency distribution of Ethmalosa fimbriata (Bowdich) in cross River Estuary and Adjacent Coastal waters

Abstract

Studies on the length distribution of bonga, Ethmalosa fimbriata, in the Cross River estuary and adjacent coastal waters were conducted from October 1999 to December 2000. A total of 15,182 specimens of bonga from gill nets, purse seine and boat seine fisheries were measured. Post-larvae measuring between 2 cm and 9 cm were found in the lower estuary with a modal length of 4 cm. Juveniles from gill net fishery ranged in length from 8 cm to 20 cm with a modal length of 13cm. Adults and sub-adults ranging in size from 16 cm to 33 cm were caught from the coastal waters alongside the juveniles, by the purse seine fishery. Two modal lengths of 17 cm and 25 cm were observed in the coastal waters. Three modal length classes were observed in the catches from the Cross River estuary and adjacent coastal waters: these are 4 cm, 13 cm and 25 cm. It is concluded that the Cross River estuary is a nursery ground for bonga, Ethmalosa fimbriata.

Key Words: Ethmalosa fimbriata, length distribution, Cross River estuary, coastal waters, nursery.


(Global Journal of Pure and Applied Sciences: 2002 8(3): 299-304)