不同地位克氏原螯虾对社会环境改变的行为反应

Behavior Response of Dominant and Subordinate Crayfish Procambarus clarkii to Social Context Change by a Larger Intruder

为探究不同社会地位的亚成体克氏原螯虾(Procambarus clarkii)对利益的分配,以及对社会环境改变(体型较大的入侵同类)各自做出的行为反应,本文统计已确立等级序列的成对同性别螯虾对隐蔽所的占有情况,并视频拍摄同性别螯虾入侵时,入侵者及不同地位的原居者的格斗行为,分析格斗次数、格斗时间、首次攻击及被首次攻击对象多个参数。在隐蔽所占有实验中,71%为优势者占有隐蔽所,7%为从属者占有,共同占有或没有占有的各11%。在入侵-反入侵实验中,雄性入侵者对2只原居虾之间的攻击选择无显著差异,雌性入侵者首次攻击显著选择与原优势者格斗;雄性原居者中优势者对入侵者和原从属者的攻击无显著差异,雌性优势者则显著选择与入侵者格斗;雄性原居者中从属者显著选择与入侵者格斗,雌性从属者对入侵者和原优势者的攻击无显著差异。上述结果表明,优势者优先占有资源;雌雄螯虾在入侵和面临入侵时有各自不同的策略;不同地位的螯虾在反入侵时行为反应也各有不同。

To study the distribution of benefits between dominant and subordinate subadult crayfish（Procambarus clarkii） and their behavior responses to social context change by a larger intruder, we set a shelter and two individuals of crayfish in the box for 3 days to identify their social ranks by recording the occupation number for the shelter each of them. Then, we introduced a larger single crayfish to the box for 30 min and taped the behavior of the three. We analyzed agonistic number and time data, the by t-test and the first attacking choice between the rest two crayfishes by Fisher′s exact test. We rejected the null hypothesis at significant level at α ≥ 0.05. 71% of the shelters were occupied by dominant one, 7% by subordinate, 11% occupied by both and the rest 11% were empty（n = 28）. Each larger intruders was put in a box with both dominator or a subordinate one for 30 minutes, the male intruder attacked the dominant more frequently than subordinate, but no significant difference in both the fight times and duration（Fig. 3a, 3b） found out between the two holders（P〈0.05）. Female intruder mostly chose to attack the dominant first, P〈0.05（Table 1）. Male dominator did not show a significant tendency to fight with intruder or subordinate in the agonistic times（Fig. 4a） and duration（P〈0.05, Fig. 4b）, while female preferred to interact with intruder（P〈0.05, Fig. 4b）; male subordinate had more aggressions to intruder than to initial dominant（P〈0.05, Fig. 5a, b）, while female subordinate showed few combat and with no difference both of intruder and dominant（P〈0.05, Fig. 5）. In this experiment, dominant had a priority to access to resource, male and female showed a different strategy when to face the intruder or to the holder. Crayfishes with different social position performed different behavior responses when they have been intruded.