Studies on the feeding habits of Labeo rohita (Ham.) from Gho-Manhasa fish ponds, Jammu, North India.

The present study was carried out to study the feeding habits of Labeo rohita from culture ponds of Gho-Manhasa fish farm, Jammu. Monthly samples were collected from the ponds to study the gut contents. In case of L. rohita in LrfI (lowest size group) and LrfII, LrfIII 40 guts/group, LrfIV 50 guts (due to non-availability of the size categorized) and 120 guts each in case of LrfV and LrfVI (largest size group) were analysed. For every group 10 guts/month were analysed to study feeding ecology in case of L. rohita. Individual stomach fullness scale was estimated to a subjective scale, ranging from 0 (empty) to 5 (full). The results so obtained were used to compute percentage volume of food items in the gut (%V), percentage of occurrence of guts having particular food item (%O) and Index of preponderance (IOP). The food of Labeo rohita consisted of plant (algae and macrophytes) and animal matter (protozoa, rotifers, cladocerans, copepods, molluscs, annelids and insects) besides unidentified matter (UM), sand/mud and detritus. Of the total 420 specimens analyzed, only 84 (20%) were found with empty guts and 336 (80%) were found with food components. Index of Preponderance (IOP) revealed that algae, along with protozoans, rotifers and cladocerans were the most preferred food items in the smaller size groups and marked a decline as the size of the fish increased. In the advanced stages, macrophytes, detritus and sand/mud were found to form a major share of food. Subsequently rohu has been categorized as omnivore-planktophage in early stages of life and herbi-omnivore in adult stages. [ABSTRACT FROM AUTHOR]