长江上游宜宾-江津与涪陵-丰都江段鱼类早期资源分布研究

The distribution of the early-stage fish resources between Yibin-Jiangjin and Fuling-Fengdu in the upper reaches of the Yangtze River

为丰富长江上游鱼类早期资源及其空间分布的资料,探寻鱼类产卵与水文动态过程的相互关系,于2019年6-7月对上游宜宾-江津与涪陵-丰都江段鱼类早期资源和涨水动态过程进行了监测。结果显示:调查期间共采集到鱼卵2 034粒,仔鱼1 086尾,隶属于4目7科54种(鱼卵18种,仔鱼53种),其中长江上游特有鱼类9种;优势种类为黄颡鱼(Pelteobagrus fulvidraco)、鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)、草鱼(Ctenonpharyngodon idellus)、长吻■(Leiocassis longirostris)和铜鱼(Coreius heterodon)。大规模产卵发生在持续涨水2 d以后,且南溪-江津和涪陵-丰都江段所需的涨水条件差异很大。空间分布上,江津上游早期资源种类明显多于下游的涪陵和丰都,其中仔鱼的种类占了70%,上游鱼卵数量虽少但发育阶段分布更广泛。

To enrich the fundamental data of early resources and their spatial distribution in the upper Yangtze River and explore the interrelationship between fish spawning and hydrodynamic processes,the dynamic variation of early-stage fish resources and flow upwelling in Nanxi-Jiangjin and Fuling-Fengdu were studied from June to July 2019.The results showed that a total of 2034 fish eggs and 1086 fish larvae were collected during the survey period.All the 54 species fish eggs(18 species)and larvae(53 species)belong to 4 orders and 7 families,among which 9 species were endemic in the upper Yangtze River.The dominant species were Pelteobagrus fulvidraco,Hypophthalmichthys molitrix,Aristichthys nobilis,Ctenopharyngodon idellus,Leiocassis longirostris and Coreius heterodon.Large-scale spawning occurred after 2 days of continuous water rising,and the magnitude required at Nankei-Jiangjin and Fuling-Fundu river sections was significantly different.In terms of spatial distribution,the identified fish species in the upper reaches of Jiangjin were significantly more than the lower reaches of Fuling and Fengdu where the species of fish larvae accounted for 70%;the number of eggs in the upper reaches was small but more widely distributed on incubation stages.