ABSTRACT

This study was carried-out from August, 2011 to May, 2012 in Tra Vinh Province. The study focused on the morphology, growth and reproductive biology of Squirrelheaded catfish (Arius sciurus). Samples (30 - 40 fishes each time) were collected monthly.

The results indicated that Squirrelheaded catfish belongs to the order Siluriformes and largely distributes in freshwater and brackishwater. There was a high correlation between length and weight in the regressive equation, W = 0.01L^2.9639 with R² = 0.9622. The von Bertalanffy growth parameters (maximum length L , growth coefficient K and the age of zero length t₀) of Squirrelheaded catfish were L = 20.65 cm, K = 0.98/year, t = -0.83 year. Maturaltion of Squirrelheaded catfish showed that the highest values of GSI (5.74%) was observed in December and the lowest one (1.12 %) in August. The fecundity ranged from 461? 1,047 eggs/female fish and the relative fecundity from 11,813?16,362 eggs/kg of female fish.

Keywords: Morphology, growth, fecundity, Squirrelheaded catfish (Arius sciurus)

Title: Study on the biology characteristics of the Squirrelheaded catfish (Arius sciurus)

ToM T?T

Nghien c?u d??c th?c hi?n t? thang 8 nam 2011 d?n thang 5 nam 2012 t?i t?nh Tra Vinh. Nghien c?u t?p trung d?c di?m hinh thai, d?c di?m sinh h?c sinh tr??ng va sinh s?n ca uc tr?ng (Arius sciurus). M?u ca (30 -40 con/l?n) d??c thu m?i thang m?t l?n.

Ca uc tr?ng thu?c b? Siluriformes va phan b? trong cac th?y v?c n??c ng?t va l?. Co s? t??ng quan gi?a chi?u dai va kh?i l??ng c?a ca uc tr?ng theo ph??ng trinh h?i qui W=0,01L^2,9639 v?i R² = 0,9622. Cac tham s? tang tr??ng c?a d??ng cong tang tr??ng Von - Bertalanffy (chi?u dai ti?m c?n c?c d?i L _, h? s? tang tr??ng K va tu?i chi?u dai b?ng 0, t₀) c?a ca uc tr?ng la: L = 20,65 cm v?i t?c d? tang tr??ng K = 0,98/nam, t = -0,83. Ch? s? GSI c?a ca uc tr?ng cao nh?t vao thang 12 (5,74 %) va th?p nh?t vao thang 8 (1,12 %). S?c sinh s?n tuy?t d?i c?a ca uc tr?ng dao d?ng t? 461?1.047 tr?ng/ca cai va s?c sinh s?n t??ng d?i t? 11.813?16.362 tr?ng/kg ca cai.

T? khoa: Hinh thai, tang tr??ng, s?c sinh s?n, uc tr?ng (Arius sciurus)