Table 1 Description of ovarian development stages in female golden trevally (Gnathanodon speciosus).

I

Ovaries were very small and transparent, found in juvenile female fish.

Ovaries contained oogonia and were in proliferation.

II

Ovaries were small, light pink in color, with small blood vessels appearing as faint rays running on the ovarian surface.

There were primary and secondary oocytes (previtellogenic oocytes), including early and late perinucleolar oocytes.

III

Ovaries have increased in volume; the two ovaries have separated. The ovary was pale yellow, firm, and elastic. This stage was defined as vitellogenesis.

Ovaries contained both previtellogenic and vitellogenic oocytes, characterized by the yolk globules and peripheral yolk vesicles.

IV

Ovaries were cube-shaped and reached its maximum size and was bright yellow in color.

Germinal vesicles (GV) started migrating from its central position to the periphery. Ovaries contained fully mature oocytes with yolk globules.

V

Ovaries were fully distended. The oocytes have been released and fallen into the ovarian cavity. The female was in spawning status.

Ovulation was characterized by ovulated oocytes, post-ovulatory follicles, and previtellogenic oocytes.

VI

In females that have finished spawning, ovaries were flaccid and markedly reduced in size, with flabby walls.

Ovaries contained disintegrated oocytes, blood vessels, and degenerated tissue.