The hybrid catfish (♀ channel catfish, Ictalurus punctatus × ♂ blue catfish, I. furcatus) accounts for ~60-70% of the production in the catfish industry due to superior performance compared to the parent species for growth, tolerance to low dissolved oxygen, seinability, increased filet yield, and disease resistance. Production of hybrid embryos is labor intensive, time consuming, and requires sacrificing slow maturing blue catfish males. Xenogenesis has been utilized to produce hybrid catfish embryos more efficiently by transplanting unsorted gonadal stem cells from immature donor diploid blue catfish into triploid channel catfish fry. Then, xenogenic channel catfish males are mated with normal female channel catfish to produce 100% hybrid progeny.
Our research has shown that injecting upwards of 100,000 mixed donor spermatogonia A or oogonia stem cells from channel catfish or blue catfish into sterile, triploid channel catfish host fry at 4-6 days post-hatch results in the highest rate of xenogenesis. Natural or semi-natural hormone-induced spawning of the xenogenic channel catfish (producing blue catfish sperm) has allowed the production of blue catfish or hybrid catfish progeny.
In this study, we assessed the spawning of xenogenic channel catfish pairings to control channel catfish pairs. Normal channel catfish females were paired with normal males or putative xenogenic channel catfish males producing blue catfish sperm and induced to spawn in flow-through spawning enclosures in 2025. Pairing xenogenic males with xenogenic females was also attempted to create blue catfish fry.
Spawning percentage for normal ♀ × normal male ♂ (producing 100% channel catfish fry), normal ♀ × xenogenic ♂ (producing 100% hybrid fry), and xenogenic ♀ × xenogenic ♂ (producing 100% blue catfish) was 50.0, 63.9, and 16.6%, respectively. Hatching percentage was 78.8, 71.5, and 72.8% for normal ♀ × normal male ♂, normal ♀ × xenogenic ♂, and xenogenic ♀ × xenogenic ♂, respectively. Fry/kg ♀ BW was 3210, 2665, and 2957 for normal ♀ × normal male ♂, normal ♀ × xenogenic ♂, and xenogenic ♀ × xenogenic ♂, respectively. In 2023, 2024, and 2025, spawning xenogenic males were given a second female to mate with and 0.0, 62.5, and 65.0% were able to spawn twice in 2023, 2024, and 2025, respectively. In 2025, one male was able to spawn a third time when a new female was given. Xenogenic pairings to produce hybrids was as successful as channel catfish pairings, so this approach appears to be a viable option to make hybrid catfish embryos.