In some air-breathing fishes, air-breathing organs become incorporated between the heart and Systematic circulation and to pump blood into these organs along with the gill, heart has to face an extra load. It may cause an increase in the heart dimension of certain fishes.
Generally, more active species possess larger heart per unit body weight than to the sedimentary fishes (Clark, 1927). The ratio of heart and body weight in Amphipnous cuchia and Channa punctata was studied by Munshi and Mishra, 1974; Hakim, 1977 respectively. Active flying fishes possess heart weight as about 2.5% of body weight, while inactive fishes has heart weight as only 0.15% of body weight (Von Skramlik, 1935). Santer et al. (1983); Poupa and Lindstrom (1983); Cameron (1985) have calculated the ratio of heart weight to body weight in fishes like Coryphaena, Flounder and Mackerel. Emery et al. (1985) also correlated the ventricle dimension in elasmobranchs to endothermy and exothermy.
Measurement of morphological characteristics enable us to estimate the cardiac output (Q) that increase linearly with body mass (Hughes, 1977). Comparative and scaling aspect of heart and body weight with reference to blood supply of cardiac fibres was studied by Poupa and Lindstrom, 1983.
A large number of data of body weight and heart weight of several species from fish to mammals was collected by Crile and Quiring (1940). Little work has been done on the morphometric studies of the heart of Indian species (Munshi and Mishra, 1974; Jha, 1985; Ghosh et al., 2003).
In the present observation, an attempt has been made to study the complete morphometrics of heart in relation to the body weight and length of Puntius ticto, Cirrhinus mrigala and Channa punctata.
MATERIAL AND METHOD
Live specimen of Puntius ticto, Cirrhinus mrigala and Channa punctata were obtained from Ganga river, Local ponds and Chaur and were acclimatized in the aquarium and plastic pools.
During