title: A snail-eating snake recognizes prey handedness.
abstract: Specialized predator-prey interactions can be a driving force for their coevolution. Southeast Asian snail-eating snakes (Pareas) have more teeth on the right mandible and specialize in predation on the clockwise-coiled (dextral) majority in shelled snails by soft-body extraction. Snails have countered the snakes' dextral-predation by recurrent coil reversal, which generates diverse counterclockwise-coiled (sinistral) prey where Pareas snakes live. However, whether the snake predator in turn evolves any response to prey reversal is unknown. We show that Pareas carinatus living with abundant sinistrals avoids approaching or striking at a sinistral that is more difficult and costly to handle than a dextral. Whenever it strikes, however, the snake succeeds in predation by handling dextral and sinistral prey in reverse. In contrast, P. iwasakii with little access to sinistrals on small peripheral islands attempts and frequently misses capturing a given sinistral. Prey-handedness recognition should be advantageous for right-handed snail-eating snakes where frequently encountering sinistrals. Under dextral-predation by Pareas snakes, adaptive fixation of a prey population for a reversal gene instantaneously generates a sinistral species because interchiral mating is rarely possible. The novel warning, instead of sheltering, effect of sinistrality benefitting both predators and prey could further accelerate single-gene ecological speciation by left-right reversal.
authors.affiliation: Biological Science Program, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.|Animal Systematics Research Unit, Department of Biology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Patchara
authors.initials: P
authors.lastname: Danaisawadi
authors.affiliation: Department of Biology, Shinshu University, Matsumoto 390-8621, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Asami
authors.affiliation: Institute of Natural and Environmental Sciences, University of Hyogo, and Museum of Nature and Human Activities, Hyogo 669-1546, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Ota
authors.affiliation: Animal Systematics Research Unit, Department of Biology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Chirasak
authors.initials: C
authors.lastname: Sutcharit
authors.affiliation: Animal Systematics Research Unit, Department of Biology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Somsak
authors.initials: S
authors.lastname: Panha
mesh_terms: D060105:Animal Shells / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D005075:Biological Evolution; D010364:Pattern Recognition, Visual; D011235:Predatory Behavior / Q000502:physiology*; D012908:Snails; D012911:Snakes / Q000502:physiology*; D013045:Species Specificity