洞庭湖通江水道鱼类资源周年动态及其洄游特征研究

为了解洞庭湖通江水道鱼类资源的周年动态及其洄游特征,2017年5月～2018年6月,对洞庭湖通江水道的仔鱼和幼鱼、成鱼进行了逐月调查。(1)共采集仔鱼19种,数量以■(Hemiculter leucisculus)最多(占总数的76. 6%),其次为子陵吻虾虎鱼(Rhinogobius giurinus)(占8. 8%)和似鳊(Pseudobrama simoni)(占4. 3%);仔鱼主要出现在4～9月,密度以6月最高(848. 8 Ind./1 000 m~3)。(2)采集幼鱼、成鱼42种,数量以短颌鲚(Coilia brachygnathus)(占总数的30. 3%)最多,其次为贝氏■(Hemiculter bleekeri)(占15. 3%)和■(占12. 2%);幼鱼、成鱼丰度以8月最高(为729尾/船/日)。(3) 4～7月,江湖洄游型鱼类的运动指数在0. 1～0. 7之间,呈现入湖趋势; 9～次年3月,江湖洄游型鱼类的运动指数在-0. 4～-0. 1之间,呈现出湖趋势;径流量是幼鱼、成鱼出、入湖的主要驱动因子。

Annual Dynamics and Migration Characteristics of Fish Resources in the Chenglingji,in the Channel Connecting Dongting Lake and the Yangtze River

In order to know the annual dynamics and migration characteristics of fish resources in the channel connecting Dongting Lake and the Yangtze River, A monthly surveys were conducted for larval, juvenile and adult fishes in the channel connecting Dongting Lake and the Yangtze River from May 2017 to June 2018. Larvae fishes were belonging to 19 species and 5 families. Hemiculter leucisculus (Basilewsky) accounted for 76.6% of the total, Rhinogobius giurinus (Rutter) accounted for 8,8% of the total, Pseudobrama simoni (Bleeker) accounted for 4.3% of the total. Larva appeared mainly in Apr to Sep, and the density was highest in June (848.8 Ind./1 000 m3). Also juvenile and adult fishes were belonging to 42 species and 9 families. Coilia brachygnathus (Kreyenberg et Pappenheim) accounted for 30.3% of the total, Hemiculter bleekeri (Warpachowsky) accounted for 15.3% of the total, and Hemiculter leucisculus (Basilewsky) accounted for 12.2% of the total. The abundance of juvenile and adult fishes was 729 each day also was the highest in Aug. The results showed that the abundance of larvae, juvenile and adult fishes showed strongly seasonal variation, both of them were higher in summer and lower in winter. From April to July, the movement index of the river-lake migratory fishes was between 0.1 and 0.7, showing a tendency of entering the lake. From August to march, the movement index was between -0.4and -0.1, showing a tendency of entering the river. The results also showed that juvenile and adult fish migrated mainly at night. And discharge were the main driving factors of fish.