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Experimental assessment of moisture effects on loggerhead sea turtle sex ratios

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Date Issued:
2015
Abstract/Description:
Nest sand temperature strongly influences development of sea turtle embryos and sex differentiation; however in nature eggs experience temperature along with other environmental factors. We tested the hypothesis that moisture effects sea turtle hatchling sex ratios. We studied the relationships among moisture, temperature, and loggerhead Caretta caretta sex ratios in an experimental study. Eggs were incubated in sterile nest sand in the laboratory under different moisture regimes to test the role of humidity at a constant incubation temperature. Incubator temperature was set at 29.4 degrees C, a temperature that is slightly above the temperature that should yield a 1:1 sex ratio. Nest moisture was maintained by daily DI water treatments and high relative humidity was maintained with the aid of a mist humidifier throughout incubation. All hatchlings were collected, raised for several months and sexed laparoscopically to establish sex ratios for each treatment. The experimental treatments tested the effects of i very high moisture, ii moisture with potential for evaporative cooling, and iii moisture added at average rain temperatures plus the potential for evaporative cooling. The nests were expected to produce a moderate female bias if moisture played no role. We found 87-96 males across all experimental treatments. Our results support our hypothesis. High moisture conditions can produce shifts in developmental response from that expected based on temperature alone.
Title: Experimental assessment of moisture effects on loggerhead sea turtle sex ratios.
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Name(s): Lolavar, Alexandra
Wyneken, Jeanette
Graduate College
Type of Resource: text
Genre: Poster
Date Created: 2015
Date Issued: 2015
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 1 p.
Language(s): English
Abstract/Description: Nest sand temperature strongly influences development of sea turtle embryos and sex differentiation; however in nature eggs experience temperature along with other environmental factors. We tested the hypothesis that moisture effects sea turtle hatchling sex ratios. We studied the relationships among moisture, temperature, and loggerhead Caretta caretta sex ratios in an experimental study. Eggs were incubated in sterile nest sand in the laboratory under different moisture regimes to test the role of humidity at a constant incubation temperature. Incubator temperature was set at 29.4 degrees C, a temperature that is slightly above the temperature that should yield a 1:1 sex ratio. Nest moisture was maintained by daily DI water treatments and high relative humidity was maintained with the aid of a mist humidifier throughout incubation. All hatchlings were collected, raised for several months and sexed laparoscopically to establish sex ratios for each treatment. The experimental treatments tested the effects of i very high moisture, ii moisture with potential for evaporative cooling, and iii moisture added at average rain temperatures plus the potential for evaporative cooling. The nests were expected to produce a moderate female bias if moisture played no role. We found 87-96 males across all experimental treatments. Our results support our hypothesis. High moisture conditions can produce shifts in developmental response from that expected based on temperature alone.
Identifier: FA00005897 (IID)
Collection: FAU Student Research Digital Collection
Note(s): The Sixth Annual Graduate Research Day was organized by Florida Atlantic University’s Graduate Student Association. Graduate students from FAU Colleges present abstracts of original research and posters in a competition for monetary prizes, awards, and recognition.
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00005897
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Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.