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Updated: Jun 26, 2026

Dissection of Larval Zebrafish Gonadal Tissue
Published on: April 26, 2017
Sex determination in flatfishes: Mechanisms and environmental influences
J Adam Luckenbach1, Russell J Borski, Harry V Daniels
1Department of Biology, North Carolina State University, Raleigh, NC 27695, USA. jalucken@u.washington.edu
Abstract:
Flounder of the genus Paralichthys exhibit a unique mode of sex determination where both low and high temperatures induce male-skewed sex ratios, while intermediate temperatures produce a 1:1 sex ratio. Male differentiation is thus easily induced in genetic females creating a combination of genetic (GSD) and environmental sex determination (ESD). Since male flounder become reproductively fit at substantially smaller body sizes than females, temperature or other environmental variables that elicit lower growth rates may also influence sex differentiation toward male development. This review covers our current knowledge of sex determination and differentiation in flatfishes including possible adaptive significance of ESD and involvement of factors such as aromatase (cyp19).
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