大鳞裂峡鲃繁殖生物学特征

Reproductive Biology of Hampala macrolepidota

2009、2010和2013年在云南省西双版纳自治州勐腊县境内的南腊河共收集大鳞裂峡鲃（Hampala macrolepidota）样本438尾。研究结果表明：大鳞裂峡鲃雌性群体初次性成熟体长228 mm、体重270.3 g,雄性群体初次性成熟体长205 mm、体重172.5 g,对应年龄均为4龄。大鳞裂峡鲃雌、雄繁殖群体的成熟系数年度变化趋势基本一致。成熟系数值在1月、3月、4月呈逐渐增大趋势,5月显著上升,6月达到最高峰,7月急速下降,8月至9月趋于平缓。繁殖活动每年4月开始,一直可持续至10月,主要集中在5~6月。大鳞裂峡鲃雌雄性比为1︰1.19,与鲃亚科其他部分鱼类雌性数量多于雄性的情况相反;繁殖盛期则雌性数量多于雄性。繁殖群体由4~8龄共5个年龄组组成,雌、雄群体均以5龄组所占比例最大。大鳞裂峡鲃属单次产卵鱼类。平均卵径1.18 mm;绝对繁殖力为63 393粒,相对繁殖力为70.04粒/g。与鲃亚科其他部分鱼类比较,大鳞裂峡鲃的卵径相对较小而繁殖力较大。

In order to study reproductive characteristics of Hampala macrolepidota, 438 samples were collected in the Nanla River in Mengla County, Xishuangbanna Autonomous Prefecture, Yunnan Province of China in 2009, 2010 and 2013（Fig. 1, Table 1）. The research results proved that the body length of the female and the male group of H. macrolepidota at first maturity was 228 mm and 205 mm, and the body weight was 270.3 g and 172.5 g, respectively. On the basis of growth equation of H. macrolepidota, the age of the female and the male group of H. macrolepidota at first maturity was both 4 years old. Yearly change of gonado somatic index of reproductive population of the female and the male group of H. macrolepidota was almost consistent. The value of gonado somatic index increased gradually from January, March to April, augmented obviously in May and reached the peak in June, but decreased rapidly in July, then tended to be steady in August and September. It began to reproduce in April, and breeding of the fish concentrated in May and June and could continue to October. Sex ratio was 1 to 1.19, that was, the female population was less than the male, which was opposite with some other species belonging to subfamily Barbinae. But the number of the female was more than the male in May and June. The age of reproductive group consisted of 4, 5, 6, 7 and 8 years. Among these, the 5 years group had the biggest percentage. The average egg-diameter in ovary at stage Ⅳ of H. macrolepidota was 1.18 mm. The distribution of egg-diameter presented a peak on the whole. H. macrolepidota belonged to total spawners based on the gonado somatic index curve and the distribution of the diameter of mature eggs. Absolute fecundity and relative fecundity were 63 393 and 70.04 per gram, respectively. The proportion to reproduction of female H.macrolepidota in 5 years group was the largest. Compared with some other species of subfamily Barbinae including Spinibarbus yunnanensis, S. sinensis, S. hollandi, Poropuntius opisthopterus and Neolissochlus wynaadensis, the average egg- diameter of H. acrolepidota was relatively smaller, but the fecundity was relatively stronger. Through the study we could make clear the reproductive characteristics of fish so as to take effective measures to protect fish breeding and their living environment in the tropical rainforests in Xishuangbanna.