Diel Feeding Patterns, Gastric Evacuation Rate and Diets of the Mullet, Valamugil seheli (Forskal) in the Mulki Estuary, West Coast of India

Diel feeding chronology of the mullet, Valamugil seheli was examined from stomach collections taken in the months of April '99, July '99 and December '99 in the Mulki estuary along the southwest coast of India. Significant differences in mean stomach content weight were found between several consecutive 3 h periods with peak fullness occurring in early morning and evening hours. The rates of gastric evacuation of natural food (decayed organic matter, diatoms, algae and fine sand grains) were measured in the field. Ninety percent evacuation of wet weight contents required an estimated 8.0 h at a temperature of 28.5 plus or minus 1.2 degree C. Stomach content analysis indicated that this species is a herbivore, feeding mainly on decayed organic matter, diatoms, algae and sand grains. Smaller sized fishes preferred higher quantities of decayed organic matter, diatoms and algae and lesser quantity of sand grains compared to bigger sized fishes. The feeding activity of V. seheli was influenced by the tidal cycle.