Food and feeding habits of marine catfish, Osteogeneiosus militaris (Linn., 1758) off Mumbai waters

Abstract

The food and feeding habits of the marine cat fish, Osteogeneiosusmilitaris\r(Linn.,1758) off Mumbai waters was studied. The species was found to be carnivorous and\rpredacious in feeding habit. Index of preponderance values indicated that, it feeds mainly on\rcrustaceans (shrimps, crabs), molluscs (bivalves, squids) and small fishes (Coilia spp., ribbon\rfish). Among the food groups, crustaceans dominate throughout the year in comparison to\rmolluscs and fishes. In the crustacean group, Acetes spp. was found to be the dominant food\ritem contributing to 43.34 per cent followed by penaeid shrimps, which shared 27.65 per cent\rof the total food in all the months. Analysis of month-wise percentage food composition\rrevealed that, the species fed the highest percentage of Acetes spp. during the month of\rNovember (34.92%) while penaeid shrimps was consumed in the largest percentage in January\r(35.10%). With respect to the size (length) of the fish, the percentage of Acetes spp. as a food\ritem was highest (52.99%) for the length group of 391-420 mm and lowest (25.64%) for 361-390\rmm. The guts were found to be empty for fishes having length of more than 420 mm. Results\rof the feeding intensity delineated that, the species is not a voracious feeder as none of the\rindividuals studied was found to have gorged or full stomach over the entire period of\rinvestigation. Among the different length groups, the highest feeding fishes were in the\rlength group of 211-240 mm. Gastro-somatic index was highest during August for males and\rduring November for females while the pooled value was highest in January (3.206).