潮間帯に生息するカサガイ類の防御行動の比較

概要

論文の詳細を見る
Defensive behaviors of three intertidal limpets against two different types of predators were observed through laboratory experiments and explained from the perspective of the modes of life in their habitats. In response to an attack by the welk Thais clavigera and T. bronni, two patellid limpets, Cellana grata and C. nigrolineata, lifted the shells up off the floor to shake the predators off their shells and thereafter ran away, while the other patellid limpet C. toreuma immediately ran away while folding its mantle around the shell. In their natural habitats, the former two species usually rest in pits and cleftsin rocks, where they can only escape toward open spaces. In contrast, the latter speciesusually rests on a wide and even rock surface, where it can escape in any directions. This difference between their resting places appears to cause different initial responses against welk offense. During attack by the starfish Coscinasterias acutispina,the two limpets C. nigrolineata and C. toreuma, which live in the same habitat as the seastar, run away in a different manner than that when the gastropod attack, while C. grata which do not live together with the starfish in its habitat kept still, resulting in being preyed successfully upon by the predator. These findings indicate that the limpets are able to recognize the predators they encounter in their habitats and thereby make appropriate defensive responses.
2009-06-30