 density, pH, and environmental background color, are also observed to alter sex ratio, which could be classified either as temperature-dependent sex determination or temperature-dependent sex differentiation, depending on the involved mechanisms.As sex-determining mechanisms, TSD and genetic sex determination (GSD) should be considered in an equivalent manner, which can lead to reconsidering the status of fish species that are claimed to have TSD when submitted to extreme temperatures instead of the temperature experienced during development in the wild, since changes in sex ratio with temperature variation are ecologically and evolutionally relevant.While TSD has been observed in many reptile and fish species, the genetic differences between sexes and molecular mechanisms of TSD have not been disclosed.