No, it's not as simple as turning baby sea turtles over and checking.
Sea turtles, like other reptiles, become either male or female due to the temperature their eggs are in. In mammals, chromosomes determine the sex of an embryo. In reptiles, external factors are what determine sex. Higher temperatures mean more females in a clutch of eggs, while lower temperatures mean more males.
But how can we be able to tell the sex of baby turtles? It's actually complicated, and we can't do it by just looking. Anatomically, the sex of sea turtles aren't obvious until they reach sexual maturity. Sea turtles reach sexual maturity when they are about 10 years old.
That doesn't mean that we have to wait, though. Scientists have figured out a surefire way to determine the sex of baby sea turtles even before they mature.
Previously, scientists would check the temperature of beaches that eggs hatched in to determine the sex of sea turtles. Of course, this doesn't really produce highly accurate results. Other techniques also aren't satisfactorily accurate, and this pushed a team of researchers to develop a better technique.
The team developed an immunohistochemical (IHC) approach that involves testing proteins in sea turtle gonads. Proteins from female turtles produce a lot of staining, while proteins from males don't. The researchers modified a technique commonly used in determining the sex of freshwater turtles and tested it on loggerhead turtles.
Loggerhead turtles have a simpler anatomy, which makes verifying the test results easy. When the team found that the test results were accurate, they decided to try the test on leatherback turtles next. Leatherback turtles have a more complex anatomy and their sex can be difficult to determine.
Rising temperatures due to climate change may be affecting sex ratios in sea turtles. In the past years, scientists have noticed that there is an overwhelming number of female sea turtles that hatched on Florida beaches. This disparity in sex ratio can negatively impact the survival of sea turtle species considered to be threatened or endangered.
The findings of the research can thus be important to sea turtle conservation efforts. As of now, sea turtle demographic profiles are difficult to build. More information can help conservationists determine how an uneven sex ratio can affect sea turtle populations.
“It’s possible that there’s been a slight female bias for a long time, but it’s unlikely to this extent,” says Boris Tezak, one of the researchers. “That’s why this research is so important—it provides a baseline to establish how adaptation strategies will go.”
Determining the sex of baby sea turtles can thus go a long way in securing their futures.
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