草鱼标志技术的初步研究

Tagging Techniques Applied to Ctenopharyngodon idellus

采用切鳍法和挂牌法对体长为11～17cm、体重50～70g的草鱼(Ctenopharyngodon idellus)进行标志研究,用铜丝从背鳍第一与第二支鳍骨间缝隙穿过,将椭圆型塑料标牌(长8mm×宽5mm×厚1mm)挂在背鳍基前,标志牌及铜丝的平均总重量为0.04g,不影响草鱼正常游泳和摄食等活动;暂养10d的标志牌保持率达到82.4%,土塘饲养70d的成活率为91.5%,标记保持率为79.9%。切鳍法标记草鱼暂养10d后,标志保持率100%,土塘饲养70d后,成活率为83.6%,80.7%的草鱼被剪鳍条已完全或接近完全再生,标记保持率只有19.3%。挂牌标记比切鳍法标记的成活率高7.9%。需要2周时间进行食性转化训练,将饲料食性转回天然食性即草食性。研究结果显示,切鳍法因切除的腹鳍可以完全再生,只适合短期标志(约30d);挂牌法具有较高的标志保持率、标牌保留时间较长和标牌醒目等特点,可用于较长时间的试验研究。2种标志方法均可应用于草鱼增殖放流的效果评估。

Tagging technique of Ctenopharyngodon idellus with body length of 11-17 cm, weighing 50-70 g was conducted by transbody-tagging and ventral fin-clipping. C. idellus was tagged with an elliptic plastic tag （8 mm×5 mm×1 mm） linked with a brass wire, 0.14 mm in diameter（total average weight of the tag and the wire was 0.04 g）, which was drilled through the interstice between the first and the second dorsal fin pterygiophores. The tag marked had no influence on fish swimming, feeding activity. After 10 days′ period of recovery culture, the tag retention rate was 82.4%. Then the tagged grass carps were reared in outdoor pond for 70 days, with survival ratio 91.5%, and tag retention rate 79.9%. C. idellus by ventral fin-clipping had 100% retention rate after 10 days′ period of recovery culture, with survival rate of 83.6% after 70 d culture.80.7% individuals of clipped ventral fins had complete regeneration or close to regeneration, with tag retention rate of only 19.3%. The survival rate of C. idellus by transbody-tagging was 7.9% higher than that by ventral fin-clipping. It was about two weeks for the grass carps feeding artificial feed to change to feed grass. As the clipped ventral fin can regenerate, ventral fin-clipping technique could be used in the short-term tagging study （about 30 d）. The tagging technique had the characteristics of high tag retention rate, long existence and high visibility, and could be used in the long time evaluation of fish release. The two tagging techniques could be used in the evaluation of multiplication and releasing of C. idellus.