How can yellow mulberry fish distinguish between male and female?

Yellow mulberry, commonly known as tooth fish, is a local fish, it is a widespread benthic fish, its reproduction and yield is second only to crucian carp catch in Nansihu Lake.

Yellow mulberry fish has a yellowish-brown body with large hard spines on its back and tail, a large head and a wide mouth. The growth is relatively slow. In the 1950s, the largest individual reached more than 200 grams, close to half a kilogram. After entering the 1980s, due to excessive capture, its weight gradually decreased, the general common individuals, length of 15 cm, weight of about 80 grams, while the female yellow mulberry is 1/3 smaller than the male individual. The reproductive ability of this kind of rain in Nansi Lake is relatively strong. Generally, two-year-old adult fish can lay about 8000 eggs at a time during the peak period from late May to mid-June every year, and its fertilization and spawning can continue from May to September. It is generally about 2000 eggs except during the high-yielding period. They dig and reel at the bottom of the lakeside grass lake to lay eggs, the fertilized eggs adhere to the aquatic plants, and their parent fish have strong ability to protect eggs and larvae, so their survival rate is quite high. The feeding habits of yellow mulberry fish are mainly shrimp and insects, followed by higher aquatic plants and a small amount of molluscs. There are a large amount of shrimp resources in the four lakes in Weishan, which provides better conditions for yellow mulberry. Therefore, the reproduction and fishing yield of this kind of rain are second only to crucian carp.