Studies on Isozyme Variations and Morphometric Relationship among three Populations of Austruca sindensis (Alcock 1900) from Pakistan

Abstract

The isozyme variability and morphometric analysis were examined in three populations of the fiddler crab, Austruca sindensis. The crab samples were collected from the three populations of A. sindensis (Sandspit, Sonari, and Sonmiani) along the coast of Pakistan. Three different enzymes, Catalase (CAT), Carbonate dehydratase (CD), Amylase (Amy) and a general protein pattern were investigated. Two isozymes were identified to be useful for the populations differentiation of A. sindensis along the coast of Pakistan. POPGENE software was used for the analysis of banding pattern, polymorphic loci, allelic frequency, heterozygosity and genetic distance of three populations of A. sindensis; while, Minitab and MS-Excel was used for the analysis of morphometric analysis. Four polymorphic loci, CAT-I, CAT-II, CD-I and CD-II were interpretable in muscle with Polyacrylamide Gel Electrophoresis (PAGE), the allele frequency differs significantly, detected in population of the Sonmiani Bay as compared with Sonari and Sandspit. The morphometric analysis showed low level of variability among the three studied populations when total 8 selected morphometric traits were analyzed (wet weight (WW), carapace length (CL), carapace width (CW), abdominal length (AL), abdominal width (AW), enlarged chela length (EL), enlarged chela width (EW), pleopode length (PL)). Multiple statistical approaches applied; regression analysis, ANOVA and Discriminant function analysis (DFA). Among all the statistical analysis used total three traits, showed significant variations among three populations (CW, EL and AL). The result of this study indicated that not only the morphological difference reflects the environmental conditions of habitat, but also the biochemical variations can be considered as the indicator of specific population dispersal.