HOKKAIDO, Japan, Nov. 16 (UPI) -- For more snails, the shell is a last line of defense, a bunker in which to hide. But according to new research, at least two snail species use their shell like a club to whack their opponents.
For some time, scientists at Japan's Hokkaido University and Tohoku University have been working with researchers at the Russian Academy of Sciences to understand how predator-prey interactions influence prey evolution.
Researchers observed and measured the defense mechanisms evolved by snail species from the genus Karaftohelix. The chief tormentor of Karaftohelix snails is the carabid beetle.
During their research, the scientists discovered two species with a unique reaction to a beetle attack. Instead of retreating into their shells, Karaftohelix gainesi, discovered in Hokkaido, Japan, and Karaftohelix selskii, found in Russia's Far East, go on the attack, swinging their shells like a club at approaching beetles.
"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," lead study author Yuta Morii said in a news release.
DNA analysis helped scientists determine the evolutionary relationship among the studied beetles, and showed the two fighters are not closely related. Scientists believe Karaftohelix gainesi and Karaftohelix selskii independently evolved their more aggressive approach to defense.
Researchers detailed their findings in a new paper published in the journal Scientific Reports.
"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 concluded.