Sex ratio, fecundity and egg development of Macrobrachium felicinum (Holthuis, ۱۹۴۹) (Crustacea: Decapoda: Natantia) in the Lower River Benue, Makurdi, Nigeria

Sex ratio, fecundity and egg development of Macrobrachium felicinum were investigated in the Lower River Benue from January ۲۰۱۸ to December ۲۰۱۸. Four hundred and eighty (۴۸۰) specimens of M. felicinum were collected from fishermen using combination of gears (drag nets, set traps and traditional gear known as “Ahina)”. The specimens were transported in icebox containing water to the laboratory for further studies. The prawns were identified to species level by the keys of Schneider.  Morphological measurements were done according to Adite et al. Body weight was taken with a top loading electronic Metler balance. The sexes were determined using morphological features according to Anetekhai. Fecundity was determined by gravimetric method. Embryonic development was characterized into five stages based on colour of egg mass. Sex ratio ranged from ۵:۱ to ۲۶:۱. Fecundity varied from ۲۳۰ to ۶۹,۷۸۲, and strongly correlated with weight (r= ۰.۸۶۰) than with length (r=۰.۷۶۰). Most of the eggs (۲۹.۱۷%) were in stage ۴. Stage ۳ and ۱ each had ۲۵%. Stage ۲ had ۱۲.۵% and the least number (۸.۳۳%) was observed in stage ۵. The presence of mostly females and all stages of egg development in the specimens projects River Benue as a likely place for both breeding and spawning of M. felicinum. Macrobrachium felicinum is recommended as a good candidates for aquaculture in Nigeria as its seeds are readily found in the wild and in freshwater.

Keywords:

Niger River prawn , Lower River Benue , Embryonic development , Fecundity , Sex ratio , Macrobrachium felicinum