Food and Feeding Habit of Brachydanio rerio (Ham), an Important Ornamental Fish of Assam, India

Danio rerio formerly known Brachydanio rerio (Ham) is an important fish globally both for experimental studies as well as ornamental fish. Brachydanio rerio is a carnivorous fish. The basic food of the species consists of insect part, chlorophyceae and plant matter. The victual spectra trend of the gut contents of the fish has been studied through the breeding and non breeding period. The breeding and the non breeding season has been estimated by the Gonodo somatic index of the fish. The RLG ranges from 0.61 to 0.77 in fish group of TL from >30-35mm. The hepatosomatic index (HSI) of the species depicts the feeding intensity of the test species. The HSI in the female of the test species shows more or less decreasing trend than the overall HSI. The species is very well adapted to feed voraciously in between surface zone, column zone and bottom zone as observed in aquarium condition. In B. rerio, the gill raker are fewer (20) and smaller in size (0.1-0.25mm), shorter, spiny and minutely serrated.Gill raker pattern reveals that Brachydanio rerio is basically carnivorous but at the time of environmental stressed condition it changes to omnivore mode of feeding.