AsianScientist (Nov. 22, 2016) – Most snails withdraw into their shells when faced with a threat, but researchers in Japan and Russia have now found some species that counterattack predators by swinging their shells, suggesting the importance of predator-prey interactions in animal evolution. Their results have been published in Scientific Reports.
The team from Hokkaido University and Tohoku University collaborated with colleagues at the Russian Academy of Sciences to closely study snail species from the genus Karaftohelix in both countries. They observed each species’ defensive behaviors against their predator, the carabid beetle, and conducted shell measurements and species comparisons. The team also used DNA sequencing to analyze how closely related the species were to each other.
They found that two snail species—K. (Ezohelix) gainesi in Hokkaido, Japan and K. selskii in the Far East region of Russia—swing their shells to hit the carabid beetles, demonstrating a very unique, active defence strategy. In contrast, other closely related snail species withdraw their soft bodies into their shells and wait until the opponent stops attacking.
“The difference in their defensive behaviors is also reflected in their shell morphology, indicating that their behaviors and shell shapes are interrelated to optimize the preferred defence strategy,” said Dr. Yuta Morii, the study’s lead author.
By analyzing DNA sequences of each species, the team also discovered that the two active-or-passive defensive methods evolved independently in the Japanese and Russian species. Their findings suggest that the selection of each method has led to the diversification of the behaviors, shapes and species of the snails.
“Our study showcases the importance of predator-prey interactions along with resource competition as major selective forces affecting the evolution of morphological and behavioral traits in organisms,” Morii added.
The article can be found at: Morii et al. (2016) Parallel Evolution of Passive and Active Defense in Land Snails.
———
Source: Tohoku University.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
