Preliminary Experimental Study on Swimming Behavior of Crucian Carp
|School||Shanghai Ocean University,|
|Keywords||Carp Velocity of flow Critical swimming speed Flow rate trend Swimming state Wagging tail frequency|
In our coastal waters, the continued increase in fishing capacity to fishing resources has brought heavy pressure, almost all coastal fisheries have suffered different degrees of resource failure. Increasing decline of fishery resources in offshore capture fisheries development shows unsustainability. Therefore, to develop aquaculture, the use of selective fishing gear and methods, has become a major economic development of China's fishery issues. As China's traditional carp farmed fish, because of its omnivorous, adaptability, reproductive capacity, strong resistance and disease resistance, etc., almost all over the country; carp is also our common economic fish, and its high nutritional value delicious, so well received by consumers. Crucian carp swimming behavior of a representative of the findings of carp swimming ability can not only enrich the connotation of its behavioral ecology, fishing gear and methods, and for the proliferation of releasing improved technology to provide a reference, but also for other aquatic organisms swimming behavior study provides data and methods. In the early 20th century, late 60s, because the fish swimming speed and escape with their fishing gear are closely related, there have been a large number of fish swimming behavior in fishing techniques in applied research. Where the maximum sustainable aquatic swimming speed, that is the critical swimming speed, can be used as an important parameter when designing trawl. When the object is to escape when caught swimming with drag in the same direction, dragging the object speed is greater than the maximum sustainable fishing swimming speed to achieve catch results. Based on fish aquaculture and protection requirements, in recent years, fish swimming ability parameters have been used to improve the design of farming systems, improved anti-wave cages and improved deepwater fishway fish ladder safety and efficiency. Swimming behavior of the fish has also been applied bionics fields. Fish swimming behavior of the fish is not only rich in theory ethology, physiology of fish and fish ecology and other disciplines of research, has become improved fishing techniques and fish aquaculture an important theoretical basis, while fisheries resource protection and management are closely related. In this paper, carp research object, the water temperature at 18 ~ 20 ℃, the use of new fishing circulating water, study their swimming ability. Research mainly divided into carp critical swimming speed and increasingly popular as the determination of the flow rate on the fish come to different critical swimming speed, flow rate trend, wagging tail frequency, swimming state influence, as well as its body length critical swimming speed, flow rate trend and wagging tail frequencies, different swimming velocity corresponding state relations. The results were as follows: (1) Experimental carp 15, the average body length of 19.45 ± 1.40 cm, weight of 200.88 ± 35.22g, measured mean absolute critical swimming speed of 92.59 ± 52.98cm / s, the maximum can reach 145.57 cm / s, and the relative length of the critical swimming speed with the increase of the body; measured relative critical experimental carp average swimming speed was 4.73 ± 2.30 BL / s, the maximum value can reach 7.03 BL / s, is absolutely critical swimming speed increases with the length of the body increases. (2) experimental carp 24, average body length of 21.40 ± 5.13cm, weight 208.68 ± 53.32g, one-tailed test fish were recorded in 0cm / s (hydrostatic group), 20cm / s, 40cm / s and 60cm / s four kinds The increasingly popular as the flow rate, four times each set of experiments swift 90min. The results show that, from 0 ~ 40cm / s, experimental carp average flow rate and wagging tail chemotaxis frequencies are as the flow rate increases, while the 60cm / s group within 90 min decreased with time. 0cm / s velocity group, the carp swim in the performance of activities without a specific direction, swimming direction relatively random; And when the flow rate reaches 40cm / s or more, that is 40cm / s and 60cm / s flow rate of two groups, the experimental Fish are showing a strong stream of chemotaxis. Four velocity group, the experimental condition was significantly different carp swimming in 0cm / s flow rate group (hydrostatic control group) \99%; 20cm / s, 40cm / s and 60cm / s three countercurrent flow groups are still mainly occupied time proportion increased from 51.0% to 78.5%, that as the flow rate increases, along with the phenomenon of counter-stationary increase; countercurrent back time allocated in proportion to 20cm / s group maximum for 13.4%; as the flow rate increases, the proportion of time allocated to counter advances from 21.6% to 5% or less; 3 flow downstream the proportion of group were 14.0%, 8.6% and 12.2%, that as the flow rate increases, the proportion of downstream decreases and then increases. 0 ~ 10min, 10 ~ 30min, 30 ~ 60min, 60min ~ 90min four time periods, 20cm / s, 40cm / s and 60cm / s flow rate of three experimental groups chemotaxis wagging tail frequency and flow rate at four time periods were significantly increased, while the hydrostatic control group had no significant difference. Which, 40cm / s flow rate set period of time in most wagging tail frequency and maximum flow rate trends, 60cm / s velocity group followed. From time to change the point of view, 0cm / s and 20cm / s flow rate group (low flow group) chemotaxis flow rate and wagging tail frequency within 90 min was not significant; 40cm / s and 60cm / s flow rate group (high velocity group) with changed significantly prolonged. And experimental carp in four time periods within 90 min wagging tail frequency flow rate trend showed a significant linear correlation between the regression formula: RF = a bTBF, the experimental value of a measured value 43.31-51.03, b values 8.27-11.04, R 0.85-0.93.