Madhu Awasthi

Phenotypic Variation in Freshwater Murrel, Channa punctatus (Bloch, 1793) from Northern and Eastern Regions of India Using Truss Analysis

Morphometric variation study was carried out using truss analysis in freshwater murrel, Channa punctatus (Bloch, 1793), to explore different phenotypic stocks of C. punctatus. Significant variation in the morphometric analysis was observed using the truss network and multivariate analysis of the three subpopulations of freshwater murrel, C. punctatus, from the two different regions of India. Principal component analysis accounted for a total variation of 91.95% by the first three principal components. PC 1 represented the variation due to size and PC 2 and PC 3 represented variations due to shape. The 95% confidence ellipses depicted the clear isolation between the samples in scatter graph of PC 1 on PC 2. The combined groups plot (DF 1 on DF 2) based on discriminant function analysis (DFA) also validated the existence of three different subpopulations. In group classification using DFA, 100 percent of all the samples were correctly classified into their original subpopulation. These results support the existence of multiracial composition of C. punctatus across the different geographical isolated sites and, thus, these findings indicate the presence of three different phenotypic stocks of C. punctatus.

Reproductive biology of the freshwater murrel Channa punctatus (Bloch, 1793) from River Gomti of Lucknow region, Uttar Pradesh, India

A total of 187 samples of Channa punctatus (Bloch, 1793) from River Gomti of Lucknow region, Uttar Pradesh were studied during 2011. The sex ratio of 1: 0.84 was not significantly different from 1:1. Monthly variation in the gonadosomatic index (GSI) and maximum number of stage IV gonads encountered in the months of May to August indicated that the spawning season extends for about 4 months and spawning was high during the monsoon season. Absolute fecundity varied from 11000 to 28000, with an average value of 14920. Fecundity was found to be highly correlated to the total length (r = 0.9201), body weight (r = 0.9133) and weight of ovary (r = 0.8536) with all correlation coefficients being highly significant (p<0.0001). Total length (TL) of fish and weight of the ovary also highly correlated (r = 0.9551, p<0.0001). This study provides primary information on reproductive parameters of C. punctatus from River Gomti which can be utilised for management of the resource.

Length-weight relationship and condition factor of five sub-populations of Trichogaster lalius (Osphronemidae) of central and eastern regions of India

Length-weight relationship along with condition factor was studied in five sub-populations of Trichogaster lalius collected from five different habitats of central and eastern parts of India characterized by different environmental conditions. Results of the current length-weight relationship study show that there is significant difference from the isometric b (3.0) value in the sub-populations of Lucknow Pond, River Gomti and Kolkata Pond, whereas there is no significant difference in the Malihabad and Barabanki sub-populations. This clearly indicates the negative allometric (b < 3) growth in the specimens collected from Lucknow, River Gomti and Kolkata and these sub-populations do not follow the cube law strictly. A positive straight line correlation was found between length and weight as the values of coefficient of correlation (r) of all the subpopulations of T. lalius varied between 0.92–0.97. The values obtained from covariance analysis for the difference between slopes of regression line for the sub-populations suggested that separate equations are required for five sub-populations of T. lalius. The Fulton’s condition factor (K) was used to evaluate the condition or fatness of fish which showed that the growth in all the sub-populations of T. lalius is satisfactory.