In some turtles , for example , males are produced at lower incubation temperatures than females ; this difference in critical temperatures can be as little as 1-2 ° C . Many fish change sex over the course of their lifespan , a phenomenon called sequential hermaphroditism .
In some turtles , for example , males are produced at lower incubation temperatures than females ; this difference in critical temperatures can be as little as 1-2 ° C . Some fish change sex over the course of their life .