A genetical and ecological diversity of fresh water prawns from Kanyakumari district, Tamil Nadu, India

Abstract

Fresh water prawns are cultured widely around the world but little is known about the levels and patterns of genetic diversity. This paper reports the RAPD analysis of four species of fresh water prawns of Atydiae and Palaemonidiae family and the genus Macrobrachium and Caridina collected from Kanyakumari district. Specimens are identified using species-specific morphological characteristics. Morphological characters have limitations of describing intra specific genetic diversity as they are polygenic and expressions can be modified by the environment. The advent of molecular technique made possible not only the genetic analysis and also the study of evolutionary relationship. Molecular analysis of the morphologically identified species are done by extracting the DNA from the animal and concentration of DNA is measured using Nanodrop spectrophotometer at a wavelength of 280nm. Further analysis was performed with RAPD (Rapid Amplified Polymorphic DNA) a PCR (Polymerase Chain Reaction) based technique. It consist of genomic DNA, amplified with randomly constructed oligonucleotides. Specific quantity of extracted DNA was then amplified by multiplex PCR using random primers and 16S rRNA gene products was then analyzed using a bioanalyzer. From the analysis, electropherograms of DNA samples were obtained and the electrophoresis gel image of the samples were obtained. Electropherogram were then overlaid on each other and the genetic variation between the four species was determined.