Article Review: Hydric environmental effects on turtle development and sex ratio

A new article published in February 2018 to the journal Zoology by Itzel Sifuentes-Romero and colleagues found that moisture conditions, and not only environmental temperature, have an effect on sex-determination in turtles.

            There is much research and it is well understood that temperature is a major sex-determinant in turtles, but this article explained how and why moisture also plays a role in the developing embryos. The researchers incubated eggs from the species Trachemys scripta elegans and used four treatments with differing temperatures and moisture levels to determine the effect of moisture on sex ratios. They found that moisture has an effect on the incubation temperature of the eggs, which is different than air temperature, and therefore is a factor in sex-determination as well as size of the developing embryos. The results showed that at temperatures of 31°C, which would normally result in a high percentage of females, actually resulted in 100% male ratio at higher moisture temperatures and almost 50% at medium moisture levels. It was therefore that determined that wetter environments results in a much higher male sex ratio.

            This research greatly adds to our knowledge of sex-determination in turtles that we’ve learned in class. We can now understand how temperature and moisture interact to determine sex in turtles. This research is extremely valuable because in endangered species, many more females are being born than males because of the rising climate. Understanding how other factors effect this sex-determination can have an impact on conservation efforts for these organisms.

https://www.sciencedirect.com/science/article/pii/S0944200617302015?via%3Dihub

Sifuentes-Romero, I., Tezak, B. M., Milton, S. L., & Wyneken, J. (2018). Hydric environmental  effects on turtle development and sex ratio. Zoology, 126, 89-97. doi: 10.1016/j.zool.2017.11.009