Changes in chemical composition during growth ofClarias batrachus (Linnaeus)
In the muscle ofClarias batrachus, variations in total nitrogen, protein nitrogen, non protein nitrogen, total water and water soluble nitrogen, total protein, pure protein, albumin, fat, moisture, ash, total inorganic and acid soluble phosphorus were found markedly influenced by the size of the fish. Excepting the ash which decreased upto 2nd size group, a substantial faIl in the relative concentration of these constituents was noted with the increasing length, the minimum being in 3rd size group. The fishes of larger size group (4th size group) contained slightly higher values. The fat value increased with the increasing size up to 2nd size group of fishes, whereas in the other size group, its value remained low. The moisture contents were found inversely related with the fat contents. The observed variations in different chemical constituents of fish with the increase in size appear to be related to the metabolic variations occurring during the growth and maturation cycle. In all size groups the electrophoretic patterns were more or less identical.