GROWTH CHARACTERISTICS OF SKYGAZER CULTER ALBARNUS IN XINGKAI (KHANKA) LAKE

Xinkai (Khanka) Lake is situated near Mishan City, Heilongjiang Province, Northeast China. The lake strides across the China/Russia border, between 132°10′—132°50′ and 44°31′—45°30′ and 69 above sea level. Total area of the lake is 4380km 2 of which 1200km 2 is in Chinese side where average depth is 4m with the deepest 10m. The lake water runs into the Okhotsk Sea via Wusuli (Ussuri) River and Heilongjiang River Culter albarnus Basilewsky is an important natural and commercial pikes in the lake. However, research on the species is so far insufficient. In this paper, 130 fish specimens were collected and investigated during 2001—2002. To determine fish age, bio-statistical analysis was used. For each fish, 5—7 scales from fish backs were taken and put in clear water for microscopic observations on scale annularity rings. In order to analyze relationship between weight and length, a formula W=aL b was used. Growth rate was calculated using Von Bertalanffy equation, for body length by L t= L ∞[e K L(t-t 0) ] and body weight by W t=W ∞[e K W(t-t 0) ] b. Weight instantaneous growth rates were calculated by G W= (lnW 2-lnW 1)/(t 2-t 1), length instantaneous growth rates by G L=(lnL 2-lnL 1)/(t 2-t 1), growth index by G Lt =[(lgL 2-lgL 1)/0.4343(t 2-t 1)]L 1, length backward calculation by L nR=LR n. Results show that relationship between body length, L(cm), and body weight, W(g), can be expressed in W=0.0077L 3.1 (r=0.9881). Lengths of the fish caught were between 18 and 86 cm, of which 30 to 31cm ones occupied 16.4%, 22 to 23cm 13.9%. Weights of the fish were between 75 and 475g, of which 125 to 174g ones accounted for 23.0%, and 75 to 124g 17.2%. Ages of the fish were from 1 to 7 years, among them 2 to 3 constituted 40%, and 4 year old fish 18%. Through observation and statistical analysis of the total catch, C. alburnus was found to be the main species. During the spawning season C. alburnus accounted for 52% of the catch and accounted for 70% of the total catch weight. The Von Bertalantty equations for the species were as follows:L ∞=153.2cm, W ∞=42000.3g, length growth coefficient K L=0.05, weight growth coefficient K W=0.06. Starting point age t 0=-1. L t=153.2[1-e -0.05(t+1) ];W t=42000.3[1-e -0.06(t+1) ] 3.1 , the growth inflection point was at t=17.6 years, corresponding to L=95.3cm, and W=12706.6g. This data suggests that fish grow was much faster before 17.6 years of age than after 17.6 years of age. Differences in relative growth rate, instantaneous growth and growth indexes also show the same trend. Based on these research results, it is suggested that in order to sustainably utilize and protect fishery resources, catch weigh of C. alburnus should be above 5000g in Xingkai Lake.