No abstract

In a world of ever-growing population, fish among foods is one of the cheapest sources for provision of high quality animal protein with values ranging from 15 to 20% (Mohanty et al., 2011). They are also an excellent source of lipid containing omega-3 fatty acid, more specifically eicosapentaenoic acid and docosahexaenoic acid (Kris-Etherton et al., 2000) which are known to have commendatory impact on cardiovascular as well as nervous system of children during pre-natal development (Tilami et al., 2018). In addition to its valuable lipid and protein composition, it is also a significant source of vitamins (vitamin A and vitamin D) and minerals (Ca, P, Fe, Zn, K, Na etc).Recently, the global fish production has peaked to 170.90 million tonnes with India being the second largest producer of fish after China (FAO, 2018). Being a riverine country, India is home to many fresh water fish species. As per the reports of National Bureau of Fish Genetic Resources (NBFGR) of India, there are around 2,246 finfish species in India of which around 765 have been identified as freshwater fish

The present study was carried out to established the relationship of total length and total weight, the relationship of total length (TL), standard length (SL), and fork length (FL) and also condition factor of native fish species Labeo bata from Kolong River of central Brahmaputra valley of Assam. A total of 334 specimens were collected for this present study from May 2018 to April 2019. The length-weight relationship (LWR) was calculated separately with male, female, and pooled data and growth was shown negative allometric (b<3). The length-length relationship (LLR) showed a linear significant relationship between total length and standard length, total length and fork length and standard length and fork length. Information on the length-weight relationship, length-length relationship and condition factor of Labeo bata from central Brahmaputra valley are quite limited. There is no such information of LWRs, LLRs, and condition factor of this fish species from this area so this result which would be helpful for scientific and sustainable management of Indian minor carp fisheries in the Kolong River of central Brahmaputra valley of Assam.

The present study was conducted to evaluate the …effect of dietary selenium on growth performance and antioxidant enzymes activity in Cirrhinus mrigala for a period of 45 days. Four numbers of experimental diets were prepared, T c for Control (0 mg organic selenium/kg of diet), T 1 (2.5 mg organic selenium/kg of diet), T 2 (5.0 mg organic selenium/kg of diet) and T 3 (10 mg organic selenium/kg of diet). The water quality parameters (temperature, DO, pH, conductivity, hardness, ammonia, nitrate and nitrite) were found to be insignificant (p > .05) among all the treatments. Superoxidase dismutase (SOD) was found to be significantly highest in T 2 (6.10 ± 0.07) when compared with the other treatments. Similarly, catalase (CAT) activity in T 1 (13.21 ± 0.13) was significantly (p < .05) different with that of Control, T 2 and T 3 . Present study also revealed that 2.5mg organic selenium/kg supplemented diet (T 1 ) showed highest results in net weight gain (15.55 ± 1.36 g), net weight gain percentage (185.88 ± 8.98%) and SGR (2.35 ± 0.06 g) compared with other experimental diet. K E Y W O R D Santioxidant enzymes, Cirrhinus mrigala, growth performance, Selenium

Dikhow River is one of the largest tributaries of the Brahmaputra river basin originating from Yezami village near Zunheboto town of Nagaland. It debouches into the mighty river Brahmaputra river at Dikhowmukh, Sivasagar district, Asam covering a length of 255.8 km contributing 0.7% runoff. The geographical area of the Dikhow catchment is approximately 3100 km 2 , covering 85% of Nagaland, 10% of Assam and 5% of Arunachal Pradesh. The study area of the entire river stretch was divided into 6 stations whose elevation ranged from 90.83 msl to 669.9 msl (3 in Nagaland and 3 in Assam). These stations were selected to study the hydro-biological profile of the river stretch, its pollution status and fish diversity from January 2019 to February 2020. The important physico-chemical water quality parameters of the river in these stations like Dissolved Oxygen (5.2-10.1 mg/L), pH (7.0-8.2), Turbidity (3.8-143.8 NTU), Total Hardness (24.02-121.01 mg/L), Total alkalinity (33-89 mg/L), etc. were found to be ambient for the survival of aquatic fauna in some parts in some period of the year.