鄱阳湖刀鲚的鉴定与资源动态研究

为研究潘阳湖刀鲚资源状况, 2019—2020 年在鄱阳湖开展鱼类资源调查工作, 采集到大量鲚属(Coilia)鱼类, 对这些样本进行了形态学和分子生物学的鉴定。随机测量 112 尾样本的上颌骨长度显著大于头长, 长颌长/头长的范围为 1.00~1.46, 平均为 1.17±0.07。使用线粒体 Cyt b 基因和 D-loop 控制区序列作为分子标记, 对 22 尾随机样本进行物种鉴定, 结果显示 22 尾样本均为刀鲚(Coilia nasus)。对其中 5 尾样本耳石的微化学特征进行了测定, 结果显示耳石锶钙比(Si/Ca)均有大于 3 的过程出现, 表明样本为溯河洄游型刀鲚。2019—2020 年, 刀鲚在鄱阳湖中的单船产量分别达到 8.1 ind/d 和 142 ind/d, 与历史数据相比, 出现了一定的增长。鄱阳湖刀鲚资源量的恢复表明长江禁渔制度实施和取消刀鲚特许捕捞制度取得了良好的效果, 建议进一步开展鄱阳湖刀鲚产卵场调查并加强栖息地保护, 促进刀鲚资源恢复。

Species identification and resource dynamics of Coilia nasus in the Poyang Lake

From 2019 to 2020, a large number of Coilia fish samples were collected during a fish resource survey carried out in Poyang Lake, Jiangxi Province, China. Morphological and molecular biological methods were used to identify these samples. Of the 112 randomly measured samples, the supermaxilla was significantly longer than the head, and the ratio of the supermaxilla/head was 1.00 to 1.46, with an average of 1.17±0.07. D-loop sequence and Cyt b sequence analysis was used to compare 22 samples, and the results confirmed that the collected samples were Coilia nasus. The microchemical characteristics of five otolith samples were measured, and the results showed that the ratio of strontium to calcium (Si/Ca) of the otoliths was greater than 3, indicating that the samples were anadromous C. nasus. In 2019 and 2020, the catch per unit effort of C. nasus in the Poyang Lake reached 8.1 ind/d and 142 ind/d, respectively. This increase is significant compared with historical data. The recovery of C. nasus resources in Poyang Lake shows that the Fishing Ban in the Yangtze River and the C. nasus fishing permit cancellation achieved positive results. Additional investigation of the spawning grounds and habitat protection are recommended to further promote the recovery of C. nasus resources in the Poyang Lake.