Meeting Abstract
Adaptations for one behavior may lead to tradeoffs in performance of other behaviors. For example, the aquatic frog, Xenopus laevis, has morphology advantageous for swimming including a mobile ilio-sacral joint, extensively webbed hind feet, and a streamlined body. However, frogs that live in aquatic environments tend to have lower jump performance than more terrestrial species. The arboreal frog, Osteopilus septentrionalis, has morphological adaptations including long hind limbs and muscle-tendon units used as elastic-recoil mechanisms that confer high jump performance. We examined swimming and jumping in Osteopilus and Xenopus to compare performance of these species. We expected to see higher jump performance in Osteopilus, but higher swimming performance in Xenopus. Jumping and swimming were recorded for both species using high-speed video. The highest values of peak velocity and acceleration of both swimming and jumping for an individual were analyzed. The average peak velocity of jumping for Osteopilus (2.5 m/s) was significantly higher than Xenopus (1.3 m/s), but there was no significant difference in average peak velocity for swimming between Osteopilus (0.94 m/s) and Xenopus (0.95 m/s). A similar pattern was seen for average peak acceleration. These results support the tradeoff between swimming and jumping in Xenopus, but show no tradeoff for Osteopilus in these parameters. The adaptations for high performance jumping seen in Osteopilus may not be detrimental to swimming performance. Alternatively, the swimming abilities of Osteopilus may be adaptive as these frogs do enter water. Additional analyses may reveal tradeoffs in other measures of performance like efficiency or endurance.
