Parallel evolution of passive and active defence in land snails.
Predator-prey interactions are major processes promoting phenotypic evolution. However, it remains unclear how predation causes morphological and behavioural diversity in prey species and how it might lead to speciation. Here, we show that substantial divergence in the phenotypic traits of prey species has occurred among closely related land snails as a result of adaptation to predator attacks. This caused the divergence of defensive strategies into two alternatives: passive defence and active defence. Phenotypic traits of the subarctic Karaftohelix land snail have undergone radiation in northeast Asia, and distinctive morphotypes generally coexist in the same regions. In these land snails, we documented two alternative defence behaviours against predation by malacophagous beetles. Furthermore, the behaviours are potentially associated with differences in shell morphology. In addition, molecular phylogenetic analyses indicated that these alternative strategies against predation arose independently on the islands and on the continent suggesting that anti-predator adaptation is a major cause of phenotypic diversity in these snails. Finally, we suggest the potential speciation of Karaftohelix snails as a result of the divergence of defensive strategies into passive and active behaviours and the possibility of species radiation due to anti-predatory adaptations.
Forest Ecosystem Management Group, Department of forest Science, Graduate School of Agriculture, Hokkaido University, Sapporo 0608589, Japan.|Graduate School of Life Sciences &Center for Northeast Asian Studies, Tohoku University, Sendai 9808576, Japan.
Yuta
Y
Morii
Institute of Biology and Soil Science, Far East Branch, Russian Academy of Sciences, Vladivostok 690022, Russia.
Larisa
L
Prozorova
Graduate School of Life Sciences &Center for Northeast Asian Studies, Tohoku University, Sendai 9808576, Japan.
Satoshi
S
Chiba
D000222:Adaptation, Physiological; D000818:Animals; D001522:Behavior, Animal; D001517:Coleoptera / Q000502:physiology; D049810:Genetic Speciation; D010641:Phenotype; D010802:Phylogeny; D011235:Predatory Behavior; D012908:Snails / Q000502:physiology*