Lethal Phenotypes and Cryptic Consequences from Extreme Developmental Conditions in Sea Turtles


Meeting Abstract

44-4  Saturday, Jan. 5 08:45 – 09:00  Lethal Phenotypes and Cryptic Consequences from Extreme Developmental Conditions in Sea Turtles WYNEKEN, J*; LOLAVAR, A; LASALA, J; Florida Atlantic Univ.; Florida Atlantic Univ.; Florida Atlantic Univ. jwyneken@fau.edu http://biology.fau.edu/directory/wyneken/index.php

Reptile species that lay their eggs and leave them unattended to incubate depend upon nest environments to be benign and promote successful hatchling production. Successful embryonic development requires a relatively narrow range of thermal and hydric conditions. Concerns about the effects of changing climates on incubation environments tend to focus upon on thermal maxima and thermal effects on embryonic sex. Here we describe developmental outcomes in sea turtles that include phenotypes that are associated with hyperthermia and desiccation. We find an increase in frequency of morphological anomalies in hatchlings that incubated for all or part of development at or above previously presumed lethal temperature. Scute abnormalities are the most common anomaly. However, we also identified a variety of craniofacial anomalies and flipper malformations. Several anomalies that were previously rare included extreme hyperlordosis and cranial neural tube defects were found in nests with high incubation temperatures. Turtles that incubated under extremely warm dry conditions hatched from nests with poor overall success. We documented several cryptic phenotypic effects that can result in delayed mortality or reduced likelihood of survival including variation in growth rates and gastrointestinal anomalies. Mortality was often associated with yolk sac inflammation, short or incomplete intestines, and rectal stenosis. Together these observations suggest that hyperthermia and desiccation during the development of these ectothermic species may contribute additive negative impacts to the populations that previously have not been appreciated.

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