Diet composition of freshwater crab, Potamon koolooense Rathbun, 1904 from hillstream of Uttarakhand

The present study was carried out to study the diet composition of freshwater crab, P. koolooense in hillstream Khoh of Uttarakhand during November, 2013 to October, 2014. Total 105 crab samples were used for the study, 35 male and 47 female were found with food in their stomach while rest of the 23 had empty stomachs. The carapace length (CL) ranged from 12mm to 49mm, carapace width (CW) from 15mm to 59mm and total weight (TW) from 2.08g to 60.12g. Stomach content analysis of the animal showed that the diet of the animal composed of animal matter, plant matter, algae, fungi, debris and unidentified materials. Animal matter ranged from (3.27-11.93%), plant matter (4.37-14.44%), algae (1.73-6.15%), fungi (0.17-1.43%), debris (28.18-40.47%) and unidentified materials (36.46-50.05%) in males while in the female animal matter ranged from (3.09-12.34%), plant matter (4.45-12.73%), algae (1.03-7.61%), fungi (0.02-3.34%), debris (23.18-43.34%) and unidentified (30.31-51.04%). Unidentified materials recorded maximum and fungi recorded minimum in both the sexes of Potamon koolooense. A significant difference was observed at p<0.05 between food groups- algae and unidentified matter in both sexes. This is the first report, to key out and quantifies the dietary items and feeding habits of crab in Uttarakhand which would be helpful in interpreting the ecological niche of the animal in mountain stream communities.