Morphometrics of the respiratory organs of a freshwater major carp,cirrhinus mrigala in relation to body weight

Abstract

The surface area of the gills of a freshwater major carp,Cirrhinus mrigala was measured in specimens of body weight range from 5.0 to 1821.0 g and the data were analysed with respect to body weight using logarithmic transformations (log Y=log a+b · log W). The slope of the regression line for total gill area was 0.8158 and for the 1st, 2nd, 3rd and 4th gill arches were 0.8013, 0.8068, 0.8157 and 0.8457 respectively. The slope value for secondary lamellae is 0.3151, whereas the intercept value for the same parameter comes to 178,887.98. The slope for average bilateral surface area of a secondary lamella is 0.5007. These results indicated differences in growth patterns for the dimensions of different gills. The growth related decrease in number of secondary lamellae per mm filament length (b= −0.1287) and gill area/g body weight (b = −0.1842) together with evidence from oxygen uptake suggests that larger fishes consume less energy per unit body weight than the smaller ones. The percentage shrinkage due to fixation in Bouin’s fluid in filament length and average bilateral surface area were 3.05±0.47% and 15.19 ±3.48% respectively.