移动声源对鲤、草鱼的诱引效果

Attraction of common carp and grass carp by moving sound

目前我国淡水水域的养殖对象大多为中、底层鱼类 ,仍主要采用传统渔具捕捞。其缺点是受底质、水深、环境以及水流等因素限制 ,要求鱼群较集中 ,劳动作业强度大。为了改进传统的捕捞作业方式 ,本研究利用鱼类的生物学特性 ,参考音响驯化技术的有关参数 ,结合投饵用 4 0 0Hz正弦波连续音移动声源对鲤鱼 (Cyprinuscarpio)、草鱼 (Ctenopharyngodonidellus)进行诱引驯化试验。结果表明 ,最初放声时 2种鱼均产生惊愕反应 ,迅速离声源而去 ;但驯化 6d后 ,鲤、草鱼在放声后迅速游向声源 ,聚集率均为 10 0 %。经移动声源驯化 6d后 ,鲤、草鱼能够跟随声源迅速移动 ,跟随率均为 10 0 % ,平均跟随时间分别为 19.8s和 2 0 .2s。t检验证实 ,2种试验鱼跟随时间无显著差异 (a =0 .0 5 ) ,说明鲤、草鱼对移动声源的诱引反应敏感。

The culture species of freshwater fisheries in China are most midwater and demersal fishes caught by traditional fishing gears and drug. However, the traditional fishing gears are always limited by environmental factors, such as substratum, depth of water, surroundings and flow etc., and the shoal of fish are required to be relatively centralized and the labor intensity of catching is great. Moreover, most reservoirs in China lie in the areas of hills and valleys, and lakes always have a large amount of float grass, in which traveling fishing gears such as sweep net and trawl cannot be used and nets setting is limited badly. So far there are no effective methods to solve the serious problem. For improving the traditional catching techniques, attraction of common carp Cyprinus carpio and grass carp Ctenopharyngodon idellus to moving sound of 400 Hz sine wave was studied by using their biological characteristics and referring to the relational parameters of acoustic taming technology. The test was divided into two steps: (1) Training with the immovable sound of 400 Hz sine wave. Underwater microphone was set on the 2nd testing spot of underwater sound pressure. Then sound was played. And bait was cast as soon as the fish did not be attracted to swim towards sound source. Time of casting bait was set as 30 s and the amount of bait was set as 3 g that was divided into 3 times to throw into. (2) Training with the moving sound of 400 Hz sine wave. While the process of casting bait in step (1) was finished, tractor was operated immediately to draw the underwater microphone to move and the behavior of shoal was observed and their following time and following ratio was noted at the same time. The speed of tractor was set as 6.5 cm/s according to the swimming speed of common carp and grass carp and the actual conditions of laboratory. The tractor was shut up when the fish did not be attracted to swim following the sound source. Then the casting bait was begun. The amount of bait was set as 5 g that was divided into 5 times to throw into. After the process of casting bait was finished, the sound was still played for 30 s. The result indicated that fish showed a fright reaction, swimming away from the sound source when sound was played at first. But after 6 d training, common carp and grass carp swam towards the sound source rapidly when sound was played and their aggregation ratio was 100% both. After arriving to the area of sound source, the fish swam round in shoals surrounding the sound source and moved up to the surface of water. Also, common carp and grass carp could follow the sound source to move rapidly after 6 d training with moving sound and showed behavior of swimming round in shoals. The following ratio of common carp and grass carp was both 100% and the average following time was 19.8 s and 20.2 s respectively. There was no significant difference in following time between the two species ( t-test, α=0.05), which verified that common carp and grass carp were sensitive to moving sound of 400 Hz sine wave. The achievement of this research will improve the catching ratio greatly in the water areas that surroundings and substratum are bad and provide further scientific foundations for application of acoustic taming technology on freshwater fisheries and exploitation of new fishing gears and fishing methods, which will be of great importance for freshwater fisheries to have a fast, healthy and sustainable development.