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2007年7月至2009年6月间,作者分别于北江中上游及流溪河上游支流采集到侧条光唇鱼(Acrossocheilus parallens)样本358尾及522尾,并对两种群的繁殖生物学特征进行了研究。两种群雌鱼及雄鱼的最小性成熟年龄均为1+龄,北江种群雌性由1+~5+龄组成,雄性由1+~4+组成,性比为雌性︰雄性=1︰1.73;而流溪河种群雌性由1+~4+龄组成,雄性由1+~3+组成,性比为雌性︰雄性=1︰1.40。北江种群繁殖群体的各年龄组体长及体重均显著大于流溪河种群。北江种群的繁殖期约为2~10月份,高峰期为3~7月份;而流溪河种群繁殖期为2~8月份,高峰期约为每年的5~7月份;繁殖期内,北江种群雌性及雄性的成熟系数均高于流溪河种群。北江种群各年龄组或体长组的绝对繁殖力、体长相对繁殖力与体重相对繁殖力均极显著大于流溪河种群。除冬季的个别月份外,北江种群雌鱼及雄鱼的肥满度均略高于流溪河种群。本文结合北江和流溪河在营养状况、捕捞压力及溪流级别上的差异对研究结果进行了分析和讨论。
From July 2007 to June 2009, the authors collected 358 and 522 Acrossocheilus parallens samples from the upper and middle reaches of the Beijiang River and the upstream of Liuxi River, respectively. The reproductive biology of the two populations Were studied. The fecundity of females and males in both groups were all 1+ years old, females of Beijiang population consisted of 1 + 5 + males, males comprised of 1 + -4 + females: males = 1︰1.73; The female population of Liuxihe consists of 1 + ~ 4 + ages, and the male is composed of 1 + ~ 3 +. The sex ratio is female: male = 1︰1.40. The body length and body weight of the breeding population of Beijiang population were significantly greater than that of Liuxihe population. The breeding season of Beijiang population is from February to October and the peak is from March to July. The breeding season of Liuxihe River is from February to August and the peak is from May to July each year. During the breeding season, Beijiang population The maturation coefficient of female and male were higher than that of Liuxihe population. The absolute fecundity, body length relative fecundity and body weight relative fecundity of Beijiang population in each age group or body length group were significantly higher than those in Liuxihe population. Except winter months, the fatness of females and males of Beijiang population were slightly higher than that of Liuxihe population. In this paper, the results of the study were analyzed and discussed based on the differences in nutritional status, fishing pressure and stream level between Beijiang River and Liuxi River.