Food and feeding habits of the endemic fish, Hypselobarbus thomassi (Day, 1874) in the Kallada River, Kerala, India

The feeding habits of the endemic cyprinid fish, Hypselobarbus thomassi (Day, 1874) was studied based on the monthly sampling in the Kallada River, Kerala, India from April 2010 to March 2011. Gut contents of 183 fish specimens were analysed and quantified using occurrence and volumetric methods. Analysis of the gut contents showed that semidigested plant matter (22.11%) was the most preferred food item of the fish followed by Bacillariophyceae (19.80%), Chlorophyceae (19.38%), semi-digested animal matter (11.21%), soil particles (9.20%), seeds of plants (6.70%), Cyanophyceae (5.51%) and miscellaneous items (6.08%). The results indicated that H. thomassi is an omnivorous-stenophagic-column feeder. The gastrosomatic index (GaSI) ranged from 3.28-7.33 with an increment from August to November coincides with the spawning season and energy preservation for gonadal development. The information on feeding ecology of H. thomassi, a critically endangered fresh water fish from Western Ghats biodiversity hotspot would be useful towards formulating proper conservation plan for the species in its natural range.