鱼类最高游速的研究

SWIMMING BEHAVIOR OF FISHES AT HIGH SPEED

据实验测试表明,鱼类最高游泳速度 U,受到鱼体长 L及温度 T制约。鱼体摆动所能达到的最高频率f被肌肉收缩时间T_(mc)所限定。本文作者从144次测试数据中,对T_(mc),、T和L的关系作了分析,推导得一组经验公式: U=KL/2T_(mc) T_(mc)=O.0236L^(0.4?88)+0.0029ln T-0.0058 ln T·L^(0.4?88)-0.0077 式中K是游泳系数,KL 是鱼尾每摆动一次使鱼体推进距离。作者指出:K是推进效率η_p、体波波长与体长的比率λ_b/L、特征波幅 A_?和尾鳍张开的高度 S_t等因素的函数,即:K=(λ_b/L)·F_1(A_?,S_t)。 作者还指出鱼类可以通过改变体波波形来较大地改变游泳速度。如:由全波式游泳改为半波式游泳时,其游速可提高一倍左右。 经分析鳕、鲐、绿线鳕等实验数据的结果表明,鱼类可以通过调节摆动幅度和尾鳍张开程度来改变推进效率,并分别给出经验公式: η_p=(1/2)(1+U/V) 绿线鳕: U/V=-349.30(A/L)~2+66.51(A/L)-2.38 鳕: U/V=-19.43(A/L)~2+4.66(A/L)+0.44 鲐: U/V=-30.33(A/L)~2+8.98(A/L)+0.11 相应地,K值有: 绿线鳕: U/L=0.75(f-0.088),K=0.69～0.97; 鳕: U/L=0.67(f+0.198),K=0.57～0.77; 鲐: U/L=0.82(f-0.0321),K=0.63～0.98。 作者建议在估算鱼的游速时,可取K=0.70。

The maximum (anaerobic) swimming speed (U) of fish are limited by the length(L) of the fish's body and the temperature (T). The maximum swimming frequencyof the tail (f) is regulated by the time of muscle contraction (T_(mo)) which in turn iseffected by the size and temperature in all species of fish. An empirical formula isdeveloped here to express these relationships:u=KL/2T_(mc)The distance of each stride is equal to KL fish length (L).T_(mc)= 0.0236L^(0.4233)+0.0028 ln T -0. 0059 ln TL^(0.4233)-0.0077Where the swimming coefficient (K) is a function of the Propellent efficiency(η_p) and ratio of body wave length to body lengh (λ_b/L), propellent efficiency isrelated to wave velocity and forward speed. The relationship between the peopellentefficiency and the specific amplitude is discussed. It shows that fish adjusts its fin areato get the best efficiency with varied specific amplitude.A set of empirical formula is derived from experimental data:η_p=1/2(1+U/V)saith:=-349.30(A/L)~2+66.51-2.38Cod: U/V=-19.43(A/L)~2+ 4.66(A/L)~2+ 0.44Mackeral:U/V = -30.33(A/L)~2 + 8.98(A/L) + 0.11 andSaith: U/L=0.75(f-0.088);K=0.69-0.97Cod: U/L=0.67(f+0.198); K=0.57-0.77Macheral:U/L=0.82(f-0.321);K=0.63-0.98It is pointed out that fish could greatly increase its swimming speed by reducingthe number of waves on body. For instance, fish will swim at double speed whenchanged its body wave from one complete wave to a half wave.A set of maximum swimming speed curves have given based on K =0.70 andN=1.