Received: 13-05-2019 / Accepted: 17-07-2019
In order to maintain, protect and develop the gene source of Onychostoma laticeps, the study of biological characteristics of O. laticepswas carried out from January 2018 to December 2018 on 300 samples of O. laticepscollected in the Giang River, Mon Son commune, Con Cuong district, Nghe An province. Results showed that all collected fish samples were in the age of ranging from 1+-3+, corresponding to the weight of 22.5-98.8 g/fish. The O. laticepsis an omnivorous species (Li/Lo was 3.08 ± 0.57). The food composition in the fish intestines was diverse, including more than 28 species, representing for 5 different animal and plant sectors, of which the algae sector was dominated (65%) compared to other sectors. There were no much differences between the Fulton fat coefficient and Clark fat coefficient, this was reflected correctly the level of the nutrient that was accumulated in fish. In nature, O. laticepsstarted breeding in early February, the average absolute fertility was 3,113 eggs, the average relative fertility was 231 eggs/g of the female. The gonosomatic index (GSI) was high during the period from February to June (Male fish ranged from 1.81 to 2.12%; Females fish from 4.62-9.80%) and reached the highest value in March (Male fish: 2.64%; Female fish: 9.80%).