Table 1. Gonad maturity characteristics

Maturity stage	Note	Female	Male
I	Immature	Small ovary up to 1/2 the length of the body cavity. It is translucent. Oocyte does not appear.	The testis is small up to 1/2 the length of the body cavity. It is whitish.
II	Maturing	The ovary is about half the length of the body cavity. It is orange and translucent, and the oocyte cannot be seen by the naked eye.	The testis is about 1/2 the length of the body cavity. It is white and about symmetrical.
III	Ripening	The ovary is about 2/3 the length of the body cavity. Ovary yellow-orange, oocyte appears. Ovary with blood vessels on the surface. No transparent eggs or translucent, eggs are still dark.	The testis is about 2/3 the length of the body cavity.
IV	Ripe	The ovary is about 2/3 up to full of the body cavity. The ovary is orange-pink with blood vessels on the surface, and eggs are apparent.	The testis is about 2/3 up to fulfilling the body cavity. It is white-soft cream.
V	Spent	Ovary shrinks down to 1/2 the body cavity. Wall is thick. There may be dark and mature eggs in the ovary that disintegrate from absorption, dark or translucent.	Testis shrinks down to 1/2 the body cavity. Wall is thick. The testis is soft.