SPECIES COMPOSITION OF FRESHWATER PRAWN JUVENILES OF THE RIVER AMBA FROM RAIGAD DISTRICT OF MAHARASHTRA

Abstract

Present study was aimed at assessing the species composition of freshwater prawns from the River Amba. The seed of Macrobrachium was collected by local fishermen using traditional wooden traps placed in the river bed. Sampling was carried out every week according to the different phases of the lunar cycle during October, 2016 to January, 2017. The species identification revealed that the composition consisted of seed of Macrobrachium rosenbergil, Macrobrachium idella, and Macrobrachium scabriculum. Monthly species composition in number showed maximum occurrence of Macrobrachium rosenbergii and Macrobrachium idella in October, 2016 and minimum in January, 2017. Macrobrachium scabriculum had maximum occurrence in November, 2016 and minimum in January, 2017. ANOVA showed significant difference (P<0.05) for the monthly occurrence. The monthly trend line of occurrence showed the negative trend with r of 0.80, 0.79 and 0.15 for M. rosenbergii, M. idella, and M. scabriculum. Lunar cycle-wise data showed the maximum occurrence on new-moon days for M. rosenbergii, waning half-moon days for M. idella and waxing half-moon days for M. scabriculum. The minimum occurrence for these juveniles was observed on full-moon days for M. rosenbergii, waxing half-moon days for M. idella and full- moon days for M. scabriculum. In statistical analysis, ANOVA showed no significant difference (P>0.05) in the seed occurrence between the lunar cycles. It is concluded that the most suitable period for maximum seed occurrence of M. rosenbergii is new-moon days of October in the river Kalu of Raigad district of Maharashtra.