2015 IPFW Student Research and Creative Endeavor Symposium



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Faculty Sponsor

Dr. Frank Paladino


Department of Biology

University Affiliation

Indiana University – Purdue University Fort Wayne


Negligible senescence, a lack of decreased reproductive output with age, is exhibited in many tortoises and freshwater turtles, although its presence in sea turtles is not yet known. Understanding whether this trait exists in sea turtles could have important implications for conservation management. To assess the importance of age and size on reproductive output in leatherback turtles (Dermochelys coriace), we analyzed growth rates and mean clutch size (egg count) of nesting adult turtles in Parque Nacional Marino Las Baulas, Costa Rica between 2004- 2014. We patrolled the beach and tagged nesting leatherbacks with Passive Integrated Transponders (PIT) to ensure permanent identification. We measured the curved carapace (upper shell) length (CCL) and curved carapace width (CCW) at each nesting event. From the PIT tag data, we calculated the “years known” of each individual and used this as an estimate of the age since reaching sexual maturity. Neophyte nesting adults had growth rates of 5mm per year. However, after 20 years, growth rates declined to almost nominal values. Our data can fill life history gaps and bring light to evidence of negligible senescence in sea turtles. If leatherback turtles reach their maximum reproductive fitness after a given amount of years of sexual maturity, conservation measures to maximize the longevity of adults could be especially beneficial.


Biology | Life Sciences

Reproduction fitness increases beyond sexual maturity in leatherback turtles (Dermochelys coriacea)

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