Multivariate morphometric variability in freshwater prawn populations of Macrobrachium dayanum (Hendersen, 1893) from Himalayan river system, India

Abstract

Macrobrachium dayanum is one of the most nutrient rich and economically important prawn species found in Chenab and Ravi rivers, the most important rivers of Northern Himalayan river system. An approach was undertaken to explore the intraspecific variations among different populations of M. dayanum from three different rivers Gho Manhasa stream (Chenab river), Taragarh stream and Mastpur stream (Ravi river). For the present study, 22 morphometric characters were subjected to multivariate analysis and out of which ten morphometric characters showed significant variations as revealed by the results of univariate ANOVA (p < 0.5). The outcome of principal component analysis accounted for 82.75% of the total variability among populations and canonical variate analysis indicated that 74.04% of the individuals were correctly classified after cross validation based on the significant differences in the morphometric characters for best separating groups. Cluster analysis revealed that three populations of M. dayanum could be grouped in two clusters indicating the possibility of occurrence of two stocks, which might demand different assessment and management strategies for distinct populations while designing management programmes for their sustainability. Moreover, molecular data will be helpful to assess the differentiation of the two stocks.