Authors: Erica J Crespi Heather Lessig
Publish Date: 2003/10/31
Volume: 138, Issue: 2, Pages: 306-311
Abstract
In the terrestrial salamander Plethodon cinereus previous work has shown that mother’s body size is positively correlated to offspring size at the time of hatching even after controlling for the effects of egg size This study was designed to determine whether maternal body size affects offspring size via preoviposition factors eg yolk quality jelly coat composition or maternal genes or postoviposition factors eg parental care behaviors parental modification of environment Gravid females were captured and induced to lay eggs in experimental chambers in which the environment was standardized Fifteen clutches were exchanged or crossfostered between female pairs differing in body size Ten females whose eggs were taken away and then returned served as controls for the crossing treatment Foster mothers did not significantly differ from control mothers in the time spent with eggs body position or number of egg movements during brooding Average egg mass measured midway through development was not significantly correlated to the body size of either the genetic or foster mother but was correlated to preoviposition oocyte size At hatching offspring body length was positively correlated to egg size and the foster mother’s body size This correlation suggests that in P cinereus postoviposition maternal effects have a greater impact on offspring size than other maternal factors incorporated into the egg prior to oviposition While our study showed that larger mothers moved their eggs less often and tended to spend more time in contact with their eggs further work needs to be done to identify the specific mechanisms through which larger mothers influence the body size of their offspring This is the first experimental demonstration of postoviposition maternal effects for any amphibian with parental careWe thank H Wilbur for his advice and guidance throughout this project We also thank the students and faculty at Mountain Lake Biological Station during the summer of 2000 for their assistance in the execution of the experiment especially E Nagy J Watters I ParkerRenga and J McGlothlin This study was funded by Mountain Lake Biological Station a National Science Foundation Research Experience for Undergraduates REU program awarded to Mountain Lake Biological Station DBI973215 and a National Science Foundation Doctoral Dissertation Improvement Grant awarded to Henry Wilbur and Erica Crespi IBN9972674
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