CATDOLL : CATDOLL: Reproductive characteristics of yellow eel

1. Characteristics and histological stages of the eel testis: Characteristics.

2. Most eels are male over the age of 3, but some begin to turn male at the age of 2.

3. The immature testis is slender, grayish white, with pigment spots on the surface. Seminiferous tubules and inactive sperm can be seen under a microscope.

4. The sexually mature testes are larger than before, with melanin spots of varying shapes distributed on the surface. Under a microscope, a large number of small active sperm can be seen.

5. The sperm of the eel is divided into head, neck and tail. The head is round and has no acrosome; there is a spherical structure on the outer edge of the neck; and the tail is thin and short.

6. Tissue staging of the testis.

7. The development of the eel's testis is divided into six stages, and the characteristics of each stage are as follows: Stage I: The testis is large in size and has dispersed spermatogonia.

8. The time is before the beginning of March every year.

9. Stage II: The testis is large in size, contains a large number of spermatogonia, and has no cavities in the spermatocysts.