Biology of Finfish and Shellfish (2+1)

4.3.2 Flatfish maturity scale

	Females	Males
1.	Juvenile Ovaries small translucent. Tunica lining silvery or dark in colour.	Juvenile Testes very small and translucent up to about 1cm long.
2.	Developing virgin / Resting spent Ovaries up to ½ of length of a full ovary. Pinkish colour, no yellow or orange colour visible.	Developing virgin / Resting spent Testes up to ½ size of full testes grey to white in colour.
3.	Ripening 1 No stage 3 for males	Ripening 1 No stage 3 for males
4.	Ripening 2 Colour yellow to orange, individual oocytes seen with the naked eye.	Ripening 2 Testes filling but no sperm visible when testes are cut. No sperm in sperm ducts.
5.	Ripe Ovaries containing few or many hydrated eggs, but will not run under moderate pressure.	Ripe Testes full but do not run under moderate pressure. When testes are cut, some sperm is visible. Sperm in sperm ducts.
6.	Running Hydrated eggs extruded on slight pressure	Running Testes run on slight pressure
7.	Spent Ovaries size reduced and flaccid. Some opaque eggs may occur with slime.	Spent Testes thin and flabby, little sperm may remain in sperm ducts.