Early sex distinction in greater amberjack Seriola dumerili using skin mucus

Abstract

Vitellogenin (VTG), a female-specific protein, was purified from the plasma of estrogen-injected greater amberjack, Seriola dumerili, and detected in the skin mucus of females immunologically, in order to utilize it for the early sex distinction of this fish. VTG purified with hydroxylapatite and gel filtration (Sephacryl S-300) had an apparent molecular weight of 430,000. When enzyme-linked immunosorbent assay was carried out in the sera and mucus of both sexes using rabbit antibody raised against VTG, the serum and mucus of the matured females reacted with the antibody but not those of the matured males. The females during the spawning season (May) had much VTG in their mucus but not males. Some fish before the spawning season had VTG in the mucus and serum. These results suggest that VTG occurs in the mucus of the females and can be utilized for the early sex distinction of this fish.