Food and feeding habits of Helostoma temmincki (Osteichthyes, Anabantidae), an introduced species, in a freshwater marsh in the wet zone of Sri Lanka
I U WICKRAMARATNE and U S AMARASTNGHE
Helosioma temmincki (Cuvier and Valenciennes) is an introduced fish species in Sri Lankan freshwaters. It occurs in several freshwater habitats in Sri Lanka. However, hitherto no studies have been reported on food and feeding habits of this species from Sri Lankan freshwater habitats. Present study was carried out to investigate the food and feeding habits of H. temmincki in Iriyawetiya marsh of the wet zone of Sri Lanka.
In the stomach contents of H. temmincki, 14 genera of diatoms, 12 genera green algae, 3 genera of blue green algae, unidentified plant particles and detritus were present. The relative gut length is related to body size of H. temmincki according to a second order polynomial curve, which perhaps indicates that the digestive tract of this species is morphologically adapted for ontogenetic variations in feeding. The logarithmic relationship between the gastro-somatic index and body length in H. temmincki indicates its higher feeding efficiency in smaller size classes than in larger size classes. Ontogenetic variations in feeding habits and isometric growth of H. temmincki may be an indication of its efficient food utilization.