You are here:
Behavioral Repertoire of Xenopus tropicalis: Baseline Female-male Interactions during Spawning Events and Male Vocal Communication
Citation:
BLAKE, L. S., S. J. DEGITZ, AND A. W. OLMSTEAD. Behavioral Repertoire of Xenopus tropicalis: Baseline Female-male Interactions during Spawning Events and Male Vocal Communication . Presented at 2010 Midwest SETAC, St. Paul, MN, March 24 - 26, 2010.
Impact/Purpose:
Our goal is to better understand mating behaviors in this species to develop behavioral endpoints for toxicity assays.
Description:
The aquatic frog, Xenopus tropicalis, is being developed for use as a model amphibian species for inclusion in the EPA’s Endocrine Disruptor Screening Program. Current toxicity test designs do not incorporate measures of fecundity due to high variability in the responses of frogs induced to mate. Our goal is to better understand mating behaviors in this species to develop behavioral endpoints for toxicity assays. We characterized the calling repertoire of X. tropicalis, either in isolation or social contexts using hydrophones. Analysis of spectrographs revealed two types of calls: 1) an advertisement call characterized by a frequency between 10 and 20 kHz and a duration length between 1 and 10 sec and 2) a male-male interaction call characterized by a frequency less than 10 kHz and duration less than 1 sec. Calling usually was initiated at the beginning of the dark cycle of the photoperiod. In isolated males this calling was absent most nights; however, males that called used advertisement calls almost exclusively and ceased calling within 1-2 hours. Both acoustic signals occurred in paired tanks more often and typically lasted throughout the dark cycle. Mating of female-male pairs was induced using human chorionic gonadotropin and videotaped overnight. Behaviors of these pairs were analyzed by enumerating male amplexus attempts, responsiveness of females to amplexus attempts, time to amplexus, time/length of spawning event, duration of amplexus, male activity while maintaining amplexus, and mating somersaults. Spawns were classified based on quality, and results suggest that the type of spawn observed was due to alterations in female behavior/responsiveness. The development and incorporation of these endpoints into proposed toxicity studies will also be outlined.