Length-Weight Relationship and Geometric Morphometric Analyses of Wild Cirrhinus reba (Hamilton 1822) From Different Regions of Bangladesh

Abstract

Cirrhinus reba, locally known as Bhangna, belongs to the Cyprinidae family, is one of the most popular minor carp species, which were abundantly available in the past. This fish is distributed in South-East Asian countries including Bangladesh. Now a days it has become endemic in some selected regions of Bangladesh such as Dinajpur, Bagura, Jashore, Mymensingh and Sylhet. Hence, in attempts were taken to this study know the present status of wild C. reba in Dinajpur, Bagura, Jashore and Mymensingh through length-weight relationship, condition factor and geometric morphometric analysis. Samples of wild C. reba were collected from the selected regions and carried to the laboratory in ice condition. The total length and weight of each individual samples were taken in nearest cm and gm respectively. Then the images of each sample were captured by Canon Power shot SX510 HS Digital Camera (4000 X 3000 megapixels). The length weight data were analyzed in PAST software (version 3.0) for determining the slope b, condition factor k and correlation coefficient r2 . The images of each sample were converted in TPS file format using tps util software (version 1.74). Then the tps file were converted to landmark coordinated file using tps Dig2 (version 2.29) software. Finally the data were analyzed using PAST software to discriminate the wild stocks through Eigenvalue, percent variance and scatter plot. The overall b value ranged from 1.22 to 4.69 where the lowest (1.22) was found in the Jamuna river sotck and followed by Bhramaputra river (3.07), Bergobindapur baor (4.44) and Atrai river (4.69). A total of 22 principal components were identified in the shape analysis among the four different regional stocks highest value fish than the lowest values of one another, where the highest Eigenvalue (553078) and Percent Variance (45.478%) for total populations were found on the PC-1. In overall geometric analysis, variation of four wild stocks were observed with lower demarcation level. Further variation of stocks in pairwise study was found. Finally the UPGMA Cluster analysis the wild C. reba of four different regions species showed stock differentiation of according to the endemic regions though few overlapping were observed among Punarvaba, Bhramaputra and Bergobindapur baor. The findings from the present study will help to broaden our understanding of the growth patterns to compare life histories of the fish species among different regions, to assess the condition of the fish, to determine biomass from underwater length observation, to observe the body shape variation and to assess possible differences between separate unit stocks of the same species.