Morphometric length-weight relationships of wild penaeid shrimps in Malindi-Ungwana Bay: Implications to aquaculture development in Kenya

Abstract

The present investigation describes the biology of penaeid shrimps and their fishery studies on morphometric length-weight relationships estimated during the two monsoon seasons from Malindi–Ungwana Bay in Kenya. A total of 1238 penaeid shrimps belonging to Fenneropenaeus indicus, Penaeus monodon, Marsupenaeus japonicus, Metapenaeus monoceros, Penaeus canaliculatus and Penaeus semisulcatus were collected from the two seasons with South East Monsoon (SEM) recording more diverse species than the North East Monsoon (NEM). The length-weight relationship analyses of most penaeid species exhibited positive allometric growth significantly different from 3.0 (p < 0.05) with strong relationship between lengths and weights of these species. The carapace length of the six penaeid shrimps at first maturity (L50) suggested that their spawning starts at different sizes with P. monodon achieving the largest size (L50 = 54.2 mm CL) while M. monoceros at the smallest size (L50 = 30.2 mm CL). Large proportions of female F. indicus, P. semisulcatus and M. monoceros had gonad stages IV and V recorded during SEM than in NEM seasons. The abundance of F. indicus and M. monoceros with matured gonads in both seasons confirms the suitability of F. indicus and M. monoceros for sustainable shrimp culture production in Kenya.