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

Abstract

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.

Extraction, characterization, and kinetics of N-deacetylation of chitin obtained from mud crab shells

“…28 This would open up the avenue for biotechnological applications due to the negligible allergenic substances in the estuarine, mangrove swamp, and freshwater crab shells. 24 Moreover, under the same deacetylation condition, the degree of acetylation (DA) of mud crab chitin (74.8%) was lower than that of chitin isolated from other crab and shrimp shells (78.6% and 88.5%), while the DD of the mud crab chitosan (88.5%) was higher compared to other crab and shrimp chitosan (83% and 88%). Although mud crab chitin and chitosan clearly showed different physicochemical properties from those derived from other crab and shrimp shells, as reported earlier in detail, 26 the fundamental aspect of the kinetics of deacetylation of the mud crab chitin remains a research challenge.…”

“…17,18 Extraction and physicochemical characterization of chitin and chitosan derived from different species of crustacean, insects, fungi, and mollusks is still one of the important research topics related to biopolymers. [1][2][3][4][5][19][20][21][22][23][24][25] Recently, we have demonstrated that the amount of chitin isolated from mud crab (Scylla serrata) shells is higher than that isolated from the shells of other crabs, shrimp shells, and cuttlefish. 26 This result suggests that this scarcely explored species of crab is a potentially rich source of chitin.…”