Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan.
Biol Lett. 2013 Feb 13;9(2):20121150. doi: 10.1098/rsbl.2012.1150. Print 2013 Apr 23.
Although it is often thought that sexual selection is weaker in simultaneous hermaphrodites than in gonochorists, some simultaneous hermaphrodites exhibit bizarre mating behaviour. In the simultaneously hermaphroditic nudibranch Chromodoris reticulata, we found a peculiar mating behaviour, wherein the nudibranch autotomized its penis after each copulation and was able to copulate again within 24 h. To have sufficient length to be replenished for three copulations, the penis is compressed and spiralled internally. No other animal is known to repeatedly copulate using such 'disposable penes'. Entangled sperm masses were observed on the outer surface of the autotomized penis, which is equipped with many backward-pointed spines. There is a possibility that the nudibranch removes sperm already stored in a mating partner's sperm storage organ(s).
虽然人们通常认为，在雌雄同体动物中，性选择比雌雄异体动物要弱，但有些雌雄同体动物表现出奇异的交配行为。在同时具有雌雄生殖器官的裸鳃类 Chromodoris reticulata 中，我们发现了一种奇特的交配行为，即裸鳃类在每次交配后会自动切断阴茎，并且在 24 小时内可以再次交配。为了使阴茎有足够的长度来补充三次交配，阴茎会被压缩并在内部螺旋化。目前还没有其他动物被发现会重复使用这种“一次性阴茎”进行交配。在自动切断的阴茎的外表面观察到纠缠在一起的精子团，阴茎上有许多向后指向的刺。裸鳃类有可能会从交配伙伴的精子储存器官中取出已经储存的精子。
