Food Preponderance Index and Feeding Habit of Macrognathus pancalus, (Hamilton, 1822) from Kotpally Reservoir Vikarabad District, Telangana State, India

The striped spiny eel, Macrognathus pancalus is a widely distributed species of fish in the Mastacembelidae family found in Asia. This study article discusses with the natural diet of M. pancalus as a first step towards understanding its feeding and nutrition, emphasising periodic dietary fluctuations and the link between fish size and diet. The study demonstrates that M. pancalus feeding strategy is more sophisticated than previous reports. GaSI provides details on the conditions around fish feeding. Prior to dissection, the fish's body weight was measured, and a weighing scale was used to determine the weight of the alimentary canal in order to determine the gastrosomatic index of the fish. The 'index of preponderance method was used to determine the relative importance of each dietary item. In the present study, 392fish species of M. pancalus relative lengths of the gut (RLG) was measured during the study period from February 22 to January 23. The study revealed minimal variation in the different sizes and lengths of fish species. The lowest value was 0.55± 0.11 in the 19–21 cm group, while the highest value was 0.68 ± 0.14 in the 6–8 cm group In general, the RLG value was higher in the younger size groups of the species. Monthly fluctuations in feeding percentage intensities of the gut were determined to be 8.38% with full gut, 23.20% with 3/4th full gut, 31.84% with 1/2th full gut, 23.79% with 1/4th full gut 7.61% with full gut, and 12.43% empty. In the present investigation, the fullness of gut in different maturity stages showed that higher active feeding (22.91% with 3/4full & 9.37% with full gut 23.52% with 1/2 full) were found in maturing stage; moderate (1/2 full with 23.52%) were found in immature stage; highest percentage of poor feeding (51.21% with empty and nearly empty29.26%) were recorded in ripe stage. More empty stomachs (16.67%) and ½ full with 26.19% were found in spent stage. The preponderance index values of M. pancalus showed that the insect larvae were the most favored food item (65.26%) for this species, followed by zooplankton (14.33%), digested food (13.76%), crustaceans (3.12%), sand and mud (2.71%), annelids (0.62%), molluscans (0.16%), and fish scales (0.007%).