Biochemical studies in the freshwater mussel, Parreysia corrugata

Abstract

1. Observations on the glycogen, fat and total nitrogen content in the mussel meat of Parreysia corrugata were made for one year. The glycogen appears to range from 4.57 to 5.73 percent dry weight in animals belonging to various size groups. The variations in the glycogen content were not found to be size dependent. Histochemical preparation showed that maximum glycogen concentration was noticed in the mantle, muscles, gills, gonads and digestive diverticula. Starving Parreysia for 15 days reduced the glycogen content. 2. The total fat content in animals belonging to various size groups ranged from 3.30 to 4.60% of dry weight. There appears to be no correlation between the size of the animal and the total fat content. By histochemical techniques the fat was found to be accumulated mostly in the gonads and the mantle. 3. The glycogen and the fat showed seasonal variations which were correlated with the spawning season as well as with gonadal changes of the animal. 4. The total nitrogen content varied from 1.42 to 2.39% of wet weight (or 6.50 to 8.00% dry weight).