The functional role of sibling aggression and “best of a bad job” strategies in cichlid juveniles
The functional role of sibling aggression and “best of a bad job” strategies in cichlid juveniles
复制标题
慈鲷幼鱼中兄弟姐妹攻击性和“最好的坏工作”策略的功能作用
DOI：
10.1093/beheco/araa150
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发表时间：
2021
影响因子：
2.4
通讯作者：
Awata Satoshi
中科院分区：
文献类型：
--
作者：
Satoh Shun;Nishida Yuusuke;Saeki Taiga;Kawasaka Kento;Kohda Masanori;Awata Satoshi
小羚羊经常争夺有限的资源，比如父母提供的食物。然而，虽然已经提出了几个功能的非致命的同胞（nonsiblicidal）侵略，目前很少有经验证据，这些，除了食物垄断。在这里，我们调查的功能，非致命的同胞攻击的双亲照顾领土食草性慈鲷Varibilichromis moorii。我们发现，这个物种的青少年是高度侵略性的，较大的青少年对他们较小的兄弟姐妹更具侵略性。较大的青少年饲料藻类更频繁地比较小的兄弟姐妹，从而表明一个优势层次。当巢中的藻类被实验性地移除时，兄弟姐妹的攻击性降低。此外，删除较小的青少年减少了兄弟姐妹之间的侵略其余较大的青少年，而删除较大的青少年增加侵略较小的青少年。幼鱼的藻类摄食率只有在较大的个体从巢中取出时才增加。此外，较大的青少年达到更高的增长率，并保持在纳塔尔巢比较小的个人更长的时间。我们的研究结果表明，兄弟姐妹的攻击可能会促进资源的垄断较大的青少年和延长父母的照顾时间。有趣的是，一小部分的青少年被观察到迁移到其他巢穴。这些青少年比那些主机育雏，其增长率增加的新巢。我们认为，下属青少年可能会分散纳塔尔的巢，潜入新的巢，以提高他们的排名，这可能是一个新的例子，一个“最好的坏工作”的战略与兄弟姐妹的竞争。
Siblings often compete for limited resources, such as food provided by their parents. However, although several functions of nonlethal sibling (nonsiblicidal) aggression have been proposed, there is currently little empirical evidence for these, apart from food monopolization. Here, we investigated the functions of nonlethal sibling aggression in the biparental-caring territorial herbivorous cichlidVaribilichromis moorii. We found that the juveniles of this species are highly aggressive and that larger juveniles are more aggressive toward their smaller siblings. Larger juveniles feed on algae more frequently than smaller siblings, thereby indicating a dominance hierarchy. Sibling aggression decreased when algae in the nest was experimentally removed. Furthermore, the removal of smaller juveniles decreased sibling aggression among the remaining larger juveniles, whereas the removal of larger juveniles increased aggression among smaller juveniles. The algal feeding rate of juveniles only increased when larger individuals were removed from the nest. Moreover, larger juveniles attained higher growth rates and remained in natal nests longer than smaller individuals. Our results indicate that sibling aggression may facilitate the monopolization of resources by larger juveniles and extend the parental care period. Interestingly, a small subset of juveniles was observed to migrate to other nests. These juveniles were larger than those of the host brood, and their growth rate increased within the new nests. We suggest that subordinate juveniles may disperse from natal nests and sneak into new nests to enhance their rank, which may represent a novel example of a “best of a bad job” strategy associated with sibling competition.