A Study On Some Aspects Of The Distribution, Biology, Ecology And Fishery Of Cryfish (procambarus Clarkii Girard) Population In Lake Naivasha

A study was conducted on the distribution of the introduced Procamoarus clarkia of Lake Naivasha and its impact on the Naivasha system and vice versa. Various field methods wer e employed •to investigate the presence of Procambarus and their burrows in diff'ererrt habitats , The results obtained showed that the eastern basin of Naivasha had a great abundance with continuous distribution of Procambarus while the main lake shoved a patchy distribution 'with low numbers of Procambarus The difference in biological performance (growth rate, maturation rate, Fecundity, mortality rate) of procambarus between the eastern basin and the main lake was the immediate cause of the observed difference in abundanc e and distribution between the 2 areas in Naivasha . Behind this difference in biological performance were external factors and among the factors food availability is suggested as the chief cause of the differing performance between the eastern basin and the main lake. Other main external factors affecting the distribution of Procambarus were namely the presence and extent of mash belt and the ecology of the hinterland eg. human activity, nature of the substrate and distance off shore.