METHODS OF DOMESTIC STRIPED BASS Morone saxatilis SPAWNING THAT DO NOT REQUIRE THE USE OF ANY HORMONAL INDUCTION PROCEDURES

We previously identified organized reproductive group spawning methods of domestic striped bass (Morone saxatilis), where several untreated female striped bass volitionally spawn in tanks with several male striped bass treated with 165 IU/kg of human chorionic gonadotrpin (hCG) to hydrate semen for better dispersal through the water column. In those trials, fish successfully spawned to produce millions of fertile eggs and fry using photothermal and water salinity manipulations with limited hormone treatments. We demonstrate here that hCG is not required at all for captive spawning of domestic striped bass using the organized reproductive group spawning method and that this hormone-free method of spawning is comparable to that of treating males with hCG in regards to egg and fry production (Figure 1). Group spawns (N = 2) that each included 19-20 hCG induced males (age 3 years) placed in tanks with 19-20 untreated females (age 4 years) produced between 8.4 and 9.7 million eggs and 2.8 to 3.1 million swim-up fry. Group spawns (N = 2) that each included 19-20 untreated males placed in tanks with 19-20 untreated females similarly produced between 4.8 and 11.4 million eggs and 1.0 to 3.8 million swim up fry. The percent of eggs harvested that produced fry in all four trials was between 20.8% and 36.6%, with an overall average of about 1/3 fry yield from eggs harvested. In all 4 trials an average of 50% of the female fish spawned. We conclude that 6^th generation domestic striped bass males and females successfully spawn together en masse to produce fry at commercial scale regardless of whether they are induced with hCG or not. This is a revolutionary advancement toward providing a consistent striped bass fingerling supply that does not rely on specialized expertise for staging or strip spawning fish.