Human chorionic gonadotropin (HCG) is often used to induce spawning offish. However, the U.S. Food and Drug Administration has not approved HCG for use in fish because they claim additional efficacy data are required. Efficacy of HCG for spawning striped bass (Morone saxatilis) and white bass (M. chrysops) was evaluated at 15 hatcheries in 10 states. For strip spawning of females, a single dose of HCG was effective for 90.2% of striped bass (N = 428) and 89.4% of white bass (N = 660). After strip spawning, hatching rates were 39.5% for striped bass and 26.1% for white bass. Of 90 striped bass and 70 white bass females injected with saline, none ovulated. Milt was obtained from all striped bass males (N = 325) and from 98.8% of white bass (TV = 862) males injected with HCG. Of 47 striped bass and 24 white bass males injected with saline as controls for the stripping technique, only 63.8% of striped bass and 37.5% of white bass produced milt. In tank spawning of striped bass, there were 87 tanks containing 1-2 females/tank and 1-4 males/tank. The HCG-injected fish spawned in every tank, and the hatching rate was 30.1%. There were 7 tanks with saline-injected striped bass; fish in only 1 tank spawned. Results demonstrated HCG was effective for inducing spawning of striped bass and white bass.
