Predation in phytotelmata: influence of snake predation risks on the behavioral, morphological, and metamorphic traits of Kurixalus eiffingeri tadpoles

碩士 === 東海大學 === 生命科學系 === 105 === Across different life stages, anurans are confronted with predation risks, and tadpoles are one of the stages that are especially vulnerable. To prevent predation, tadpoles, induced by predation risks, alter their behavioral, morphological, and metamorphic traits. H...

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Bibliographic Details
Main Authors: HU, JIA-JIUN, 胡家郡
Other Authors: KAM, YEONG-CHOY
Format: Others
Language:en_US
Published: 2017
Online Access:http://ndltd.ncl.edu.tw/handle/e65qdg
Description
Summary:碩士 === 東海大學 === 生命科學系 === 105 === Across different life stages, anurans are confronted with predation risks, and tadpoles are one of the stages that are especially vulnerable. To prevent predation, tadpoles, induced by predation risks, alter their behavioral, morphological, and metamorphic traits. However, even though tadpoles living in phytotelmata should confront greater threats, their predator-induced changes have never been examined. Therefore, in order to examine the predator-induced changes of tadpoles living in phytotelmata, I used Kurixalus eiffingeri tadpoles which inhabit small water bodies in bamboo stump as an animal model and selected the snake Lycodon ruhstrati ruhstrati as the predator. First, I observed the foraging behavior of L. ruhstrati ruhstrati in the lab and found that its behavior is similar to that of garter snakes. Next, in finding out whether K. eiffingeri tadpoles exhibit predator-induced changes, I dripped water that the snake soaked in or water containing shredded tadpoles into each tadpole’s cup as chemical cues of predation risk and observed their subsequent changes. Results showed that tadpoles increased their activity when sensing predatory cues from snakes that have eaten tadpoles. This result is the opposite of what was found in previous studies. Because K. eiffingeri tadpoles live in an extremely restricted water body, decreasing activity may not prevent them from encountering predators. Rather, they increase their activity to prevent being caught by snakes. In addition to behavioral traits, K. eiffingeri tadpoles developed deeper tail muscles, which could enhance swimming speed, but they did not alter their metamorphic traits due to that their foraging behavior was not affected by predation risks. Tadpoles, when sensing predatory cues, may increase their activity and develop deeper tail muscles to increase their survival in predation events. This study provides the reactions of anuran larvae when they face predation risks and could help understand the anti-predator strategies of tadpoles living in phytotelmata and their adaptive values.