Investigation on Feeding, Growth and Condition Factor of Certain Ornamental Fish From Brahmaputra River at Dibrugarh, Assam, India

The investigation has been carried out from different landing site of the Brahmaputra River at Dibrugarh, Assam, India during February, 2014 to January 2015. As a whole, the relative length of gut (RLG) value was found to be highest during pre-monsoon and lowest during winter season. Among the examined species, Trichogaster fasciata was recorded as highest RLG value (5.74) and the lowest (1.10) was recorded in Mystus tengara. The value of RLG reveals that the feeding habit shows a variation from species to species. In case of gastrosomatic index (GSI), out of the examined species, Esomus danricus was found to be the highest (6.5) during pre-monsoon and Osteobrama cotio was lowest GSI (2.32) during winter season. The feeding intensity was found to be more or less similar in all the species. Again, in relation to the growth co-efficient 'b' of all the examined species, Puntius sophore was recorded as highest 'b' value (3.31) during monsoon while Osteobrama cotio was recorded as lowest (2.50) during winter season. Further, it predicts that the examined fish species did not follow the cube law and showed the allometric growth. The highest (1.85) condition factor (K) was recorded in P sophore and observed in monsoon. In case of its lowest (1.0) was recorded in Salmostoma bacaila and observed in winter seasons. They were found in health and well-being condition