The ecology and growth biology of <I>Farfantepenaeus notialis</I> (Pérez-Farfante, 1967) from an open tidal estuary in Nigeria

Abstract

The environmental factors controlling the distribution of F. notialis in Lagos Lagoon in relation to its growth biology were investigated. The physico-chemical parameters obtained in this study showed variations with season. The most important ecological parameter, salinity generally alternated between 5.4‰ recorded in June and 23‰ in April, 2016. Carapace length ranged from l.4cm to 12.lcm and weight from 1.1g to 23.7g. The shrimp exhibited negative allometric growth (b < 3). Correlation co-efficient ‘r’ ranged between 0.3067 and 0.3536 showing a positive relationship between carapace length and total weight. The highest K-values were recorded for the small size group (1.0 - 1.4 cm) and the female had the highest K value. K-values decreased with increasing size of shrimp. The shrimps could be said to be detritivorous in their mode of feeding with algae, diatom and plant materials constituting the most important food items. Sex ratio was 1: 0.46 while the Chi- squared value at 1 d.f and 5% significant level was 83.63. Males were significantly (P < 0.05) more numerous than females. From this our findings, a biological database is established for use by fishery managers and in further research on the aquaculture potentials of this species.