锦鲫幼鱼的社群等级地位及其与标准代谢率、血糖和临界游泳能力的关系

在(25.0±0.5)℃实验室条件下,考查标记后体重相近的30尾锦鲫幼鱼(3.5±0.1g)的标准代谢(standard metabolic rate,SMR),然后将实验鱼分为10个组(每组3尾);分别以好斗行为和摄食成功率两个指标将各组实验鱼评估为3个不同的社群等级;再分别测定各等级地位实验鱼的SMR、血糖浓度和临界游泳速度(critical swimming speed,Ucrit)。结果显示:锦鲫幼鱼3个等级地位由高到低的摄食成功率分别为(51.2±1.61)%、(29.3±1.87)%、(19.5±0.73)%;好斗行为指标得分分别为(8.1±0.30)、(1.9±0.30)、0.0,两个评估指标均存在显著性差异(P0.05);Ucrit分别为(35.5±0.22)、(33.7±0.66)、(29.8±1.02)cm/s,血糖浓度分别为(3.4±0.22)、(4.2±0.30)、(4.5±0.33)mmol/L(P0.05);而评估前、后各等级之间实验鱼的SMR均没有显著差异(P0.05)。结果表明:锦鲫幼鱼存在着明显社群等级分化的现象;好斗行为和摄食成功率两个指标分别对社群等级地位的评估结果具有显著的一致性;实验鱼等级地位越高其游泳能力越强,血糖浓度越低;这一现象提示,高等级地位的鱼受到较低的社群胁迫且具有较高的生理适合度。

Social status of juvenile Carassius auratus and its relationship with standard metabolic rate, critical swimming speed and blood glucose concentration

The social status of alican blue-marked juvenile crucian carp(n=3/group,total 3 groups,w:((3.5±0.1)g)was divided into 3 levels based on values of successful feeding rate and aggressive behaviour at(25.0±0.5)℃Prior to social status identification,standard metabolic rate(SMR)for each fish was determined.After fish were grouped into their respective social level using aggression behavior and feeding rate a8 parametersblood glucose concentrations and critical swimming speed(Ucrit)were measured.The successful feeding rate of juvenile crucian carp of 3 social status levels(hish to low)were(51.2±1.61)%,(29.3±1.87)%and(19.5±0.73)%;meanwhile the aggressive behaviour scores were (8.1±0.30),(1.9±0.30)and 0.0,respectively(P＜0.05).However,the Ucrit in fish with different social status (high to low)were(35.5±0.22),(33.7±0.66)and(29.8±1.02)cm/s(P＜0.05)and the blood glucose concentrations were(3.4±0.22),(4.2±0.30)and(4.5±0.33)mmoL/L(P＜0.05).There was no significant difference in SMR of fish of different social status before and after social status was established and identified(P＞0.05).The results showed that social hierarchy is present in juvenile crucian carp and can be consistently determined using feeding success rate and aggressive behavior as the indicators. Furthermore.fish of higher social status had a hiigher swimming capacity and lower blood glucose concentrations which may imply lower levels of stress and a greater fitness of physical activity.