Density-dependent aggression, courtship, and sex ratio in a fishing spider
Density-dependent aggression, courtship, and sex ratio in a fishing spider
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钓鱼蜘蛛的密度依赖性攻击、求爱和性别比例
DOI：
10.13156/arac.2019.18.3.295
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Tom A R Price
中科院分区：
文献类型：
--
作者：
A. Fisher;Tom A R Price
摘要 性同类相食在蜘蛛中很常见，通过增加产卵量有利于雌性的健康。然而，在低交配密度的情况下，雌性可能会面临在交配前吃掉所有遇到的雄性的风险。如果雌性食人动物因配偶可用性低而降低食人率，那么它们也许能够降低处女死亡的风险。在这里，我们试图操纵感知的交配密度，并观察它是否影响沼泽蜘蛛（Dolomedes fimbriatus）中雌性对雄性的攻击性。我们预测，随着男性遭遇数量的增加，女性的攻击率将会增加。我们还记录了雄性求爱的努力。尽管之前的文献发现 D. fimbriatus 雌性对同种雄性具有高度攻击性，但我们发现雌性仅在 14% 的遭遇中攻击求爱的雄性。这些袭击都没有导致同类相食。此外，攻击行为与雌性之前接触过多少雄性无关。由于反复接触雌性，雄性的求偶努力会减少。一些处女雌性产下并守护着未受精的卵盒；这使得它们对雄性失去吸引力，可能会过早缩短它们的生殖寿命。
Abstract Sexual cannibalism is common in spiders and can be advantageous for female fitness by increasing egg production. However, it is possible that, under low mate density, females will be at risk of consuming all of the males they encounter prior to copulation. Cannibalistic females may be able to mitigate the risk of virgin death if they reduce cannibalism rates in response to low mate availability. Here, we attempted to manipulate perceived mate density and observe whether it affected female aggression towards males in the fen raft spider (Dolomedes fimbriatus). We predicted that female attack rate would increase in response to an increasing number of male encounters. We also recorded male courtship effort. Despite previous literature finding that D. fimbriatus females were highly aggressive towards conspecific males, we found that females only attacked courting males in 14% of encounters. None of these attacks resulted in cannibalism. Moreover, attacks were not associated with how many males the female had previously been exposed to. Male courtship effort decreased in response to repeated exposure to females. Some of the virgin females laid and guarded unfertilized egg cases; this made them unattractive to males, potentially reducing their reproductive lifespan prematurely.