黄鳍金枪鱼幼鱼日周期性及摄食期间的运动行为规律

Daily periodicity and movement behavior rule of juvenile yellowfin tuna(Thunnus albacares)during ingestion period

  • 摘要: 【目的】在陆基循环水养殖的基础上进行黄鳍金枪鱼(Thunnus albacares)幼鱼运动行为学研究,并构建设施化金枪鱼养殖技术体系,为后续开展金枪鱼深远海养殖和陆基循环水养殖推广打下基础。【方法】以驯化成功后的黄鳍金枪鱼幼鱼(驯化30 d)为研究对象,在室内集约化循环水养殖系统下运用水下摄像技术测定其全长—口径关系,以及摄食与非摄食状态下的游泳速度和深度,并分析其摄食及日周期性运动行为。【结果】黄鳍金枪鱼幼鱼的游泳速度在早晨、傍晚时巡游速度较慢,在8:00—10:00和14:00—16:00时的巡游速度较快;其最初发现食物时暴发游泳速度较快,可达1.84~3.90 m/s,冲刺距离为4.80~5.51 m;摄食中黄鳍金枪鱼幼鱼冲向食物的速度为0.98~1.54 m/s,冲刺距离为0.61~1.09 m。黄鳍金枪鱼幼鱼的初始投喂摄食深度为0.83~1.43 m,其摄食深度(y)与投喂时长(x)的线性方程式为y=0.0002x2–0.021x+1.168(R2=0.360)。随着投喂时间的延长,黄鳍金枪鱼幼鱼个体间的摄食深度相差逐渐增大。黄鳍金枪鱼在全长为38.63~51.25 cm时,其45°口径范围为1.87~3.38 cm,90°口径范围为3.45~6.00 cm,体长与口径呈正相关。黄鳍金枪鱼在陆基循环水养殖过程中,早晨(6:00)所处的水深位置最深,8:00—18:00时有轻微波动;摄食深度则随着投喂时间的延长呈由深到浅再缓慢到深的变化趋势。【结论】黄鳍金枪鱼幼鱼在陆基养殖状态下仍存在周期性的游泳速度和游泳深度变化;随着饥饿度的降低,黄鳍金枪鱼幼鱼的摄食积极性逐渐降低,且为保护自身安全,食物距池底<0.70 m时不会主动摄食。该结论可为黄鳍金枪鱼的节律性栖息深度及游泳行为研究积累基础数据资料,同时为优化黄鳍金枪鱼陆基养殖技术提供指导。

     

    Abstract: 【Objective】To study the movement behavior of juvenile yellowfin tuna(Thunnus albacares)on the basis of land-based recirculating aquaculture,and to establish an institutionalized tuna aquaculture technology system,so as to lay a foundation for the follow-up development of deep sea aquaculture and land-based recirculating aquaculture in China. 【Method】Acclimatized juvenile yellowfin tuna(acclimated for 30 days)were tested in an indoor intensive recirculating aquaculture system,and their ratio of full-length to diameter,swimming speed and depth during ingestion and non-ingestion period were determined by underwater camera technology to analyze their ingestion and daily periodicity movement behavior.【Result】The swimming speed of juvenile yellowfin tuna was slower in morning and at dusk,but faster at 8:00- 10:00 and 14:00-16:00. When it first found food,the swimming speed was faster,reaching 1.84-3.90 m/s,and the sprint distance was 4.80-5.51 m. Juvenile yellowfin tuna rushed to food at a speed of 0.98-1.54 m/s during ingestion and sprint distance of 0.61-1.09 m. The initial ingestion depth of juvenile yellowfin tuna ranged from 0.83 m to 1.43 m,and the linear equation between ingestion depth(y)and feeding time(x)was y=0.0002x2–0.021x+1.168(R2=0.360). With the extension of feeding time,the difference of ingestion depth among juvenile yellowfin tuna increased gradually. When the total length of yellowfin tuna was 38.63-51.25 cm,its 45° diameter was 1.87-3.38 cm,and its 90° diameter was 3.45-6.00 cm. The body length was positively correlated with the diameter. In the process of land-based recirculating aquaculture,the water depth of yellowfin tuna was the deepest at 6:00 in the morning and fluctuated slightly from 8:00 to 18:00. The ingestion depth changed from deep to shallow and then slowly to deep with the extension of feeding time.【Conclusion】Juvenile yellowfin tuna still have periodic changes in swimming speed and swimming depth under land-based culture condition. As the feeling of hunger declines,juvenile yellowfin tuna are gradually less and less motivated to ingest. To ensure their safety,yellowfin tuna will not ingest actively when the distance between food and the bottom of the pool is less than 0.70 m. This conclusion can provide basic data for the study on the rhythmic habitat depth and swimming behavior of yellowfin tuna,and guide the optimization of yellowfin tuna land-based breeding technology.

     

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