瓦氏黄颡鱼的繁殖生物学研究

研究了长江中游嘉鱼至新滩口江段瓦氏黄颡鱼的繁殖生物学。性腺发育可分为6个时期。4-7月性成熟系数较高,为繁殖季节。雌、雄鱼的肥满度和脂肪系数在繁殖前和繁殖后各出现1个峰值,繁殖期出现最小值。绝对繁殖力为1088-19765(粒),平均7728±4093(粒);相对繁殖力为23-88(粒),平均55±16(粒)。绝对繁殖力与体长、体重和年龄呈显著的正相关,其中体重与绝对繁殖力的关系最密切。群体性比接近1:1。属一次性产卵类型。两性最小性成熟年龄均为2龄。为补充群体占优势的繁殖群体。

STUDIES ON THE REPRODUCTIVE BIOLOGY OF PELTEOBAGRUS VACHELLI (RICHARDSON)

From October 1996 to September 1997, 941 specimens collected in the middle reaches of Yangtze River for the studies on the reproductive biology of Pelteobagrus vachelli (Richardson).During the spawning periods from April to July, stages 4, 5, or 6 of the ovaries were found, and the gonadosomatic index (GIS) is much higher than that in the other months. The absolute fecundity of P. vachelli ranges from 1088 to 19675 eggs with a mean of 7728 eggs, and the relative fecundity varies from 42 to 58 eggs with a mean of 55 eggs. The relationships between the absolute fecundity and body length (L) , body weight ( W) , and age (Yr) could be expressed as F = 0.04L231, F = - 3388.22 111.79w -0.16w2 , and F = - 4743.03 5726.22yr - 418.32;yr2, respectively.The sexual ratio of female to male is 1:1, and no obvious difference between the spawning and non-spawning periods. Age of the first maturity is 2 years old. The minimum size of matured female and male are respectively 133 and 161 mm in body length. The spawning stock mainly consists of age 2 and 3 groups.