野生与人工繁育鳄蜥游泳能力比较

Comparison of Swimming Ability between Wild and Captive Breeding Shinisaurus crocodilurus

以广西大桂山鳄蜥国家级自然保护区人工繁育的57只成体鳄蜥和北娄片区野外的35只野生成体鳄蜥为实验样本,将其分为人工繁育的成体雄性组、非怀孕成体雌性组和野生的成体雄性组、非怀孕成体雌性组共4组。在环境温度26℃、水温26℃条件下,测定鳄蜥的游泳能力(瞬时游速和最大持续运动距离)和身体各项指标。两因素方差分析结果显示:鳄蜥的游泳能力无性别差异(P>0.05);野生鳄蜥的瞬时游速(0.67±0.12 m/s)显著高于人工繁育鳄蜥(0.51±0.10 m/s)(F 1,88=48.941,P<0.001),但最大持续运动距离无显著差异(F 1,88=0.594,P=0.443),性别和分组(人工繁育鳄蜥与野生鳄蜥)的交互作用对鳄蜥的游泳能力无显著影响(P>0.05)。鳄蜥的身体测量值与其游泳能力相关性分析结果显示:鳄蜥的体质量、腹长、头体长、尾高、股骨长与其瞬时游速均极显著相关(P<0.01);鳄蜥的肥满度、尾周长、尾部体积与其瞬时游速均显著相关(P<0.05);鳄蜥的头体长、体质量、尾高与其最大持续运动距离均极显著相关(P<0.01);鳄蜥的尾周长、尾部体积、肥满度与其最大持续运动距离均显著相关(P<0.05)。逐步回归分析显示:股骨长和尾部体积是影响鳄蜥瞬时游速的主要因素(P<0.001),尾高是影响最大持续运动距离的主要因素(P=0.003)。研究结果表明,人工繁育会导致鳄蜥游泳能力下降。为使鳄蜥的野外放归个体保持较好运动能力,应加强人工繁育鳄蜥运动能力的训练。

The experimental animals were 57 captive breeding adults Shinisaurus crocodilurus and 35 wild adult S.crocodilurus in Daguishan Nature Reserve,Guangxi,China.These individuals were divided into captive breeding adult male group,captive breeding non-pregnant adult female group,wild adult male group and wild adult non-pregnant adult female group.The swimming abilities of S.crocodilurus(sprint swimming speed and maximum distance of continuous movement)were measured at the ambient temperature of 26℃and the water temperature of 26℃.Two-way analysis of variance showed that:There was no gender difference in swimming abilities of S.crocodilurus(all P>0.05);however the sprint swimming speed of wild S.crocodilurus(0.67±0.12 m/s)was significantly higher than that of captive breeding S.crocodilurus(0.51±0.10m/s)(F1,88=48.941,P<0.001);there was no significant difference in the maximum distance of continuous movement(F1,88=0.594,P=0.443).The interaction of sex and grouping(captive breeding and wild S.crocodilurus)had no significant effect on the swimming abilities of S.crocodilurus(all P>0.05).According to the correlation analysis:The body weight,abdomen length,snout-vent length,tail height,and femur length were extremely significant correlated with its sprint swimming speed(all P<0.01);the fat fullness,tail circumference and tail volume were significantly correlated with its sprint swimming speed(all P<0.05);the snout-vent length,body weight and tail height were extremely significant correlation to its maximum distance of continuous movement(all P<0.01);the tail circumference,tail volume,and fat fullness were significantly related to its maximum distance of continuous movement(all P<0.05).The results of stepwise regression analysis showed that femoral length and tail volume were the main factors that affecting the sprint swimming speed(P<0.001).The tail height was the main factor affecting the maximum distance of continuous movement(P=0.003).The results showed that captive breeding condition will lead to decline in the swimming abilities of S.crocodilurus.In order to keep wild released individual with enough movement ability,artificial training is necessary to strengthen movement ability of captive breeding S.crocodilurus.