PRODUCTION OF CHANNEL CATFISH Ictalurus punctatus ♀ X BLUE CATFISH Ictalurus furcatus ♂ HYBRID PROGENY USING XENOGENESIS  

Xenogenesis was studied as a method to produce hybrid catfish fry via mating xenogeneic males with normal channel catfish I. furcatus females. This technology could reduce or eliminate the intensive labor and sacrifice of blue catfish males currently required to produce hybrids by hand-stripping and artificial fertilization. The primary goal is to produce naturally spawned hybrids using xenogeneic catfish.

Stem cells isolated from blue catfish were transplanted into confirmed triploid channel catfish. The transfer of stem cells was done at three life stages: blastula injection, sac-fry injection, and catheterized sub-adult injection. The xenogeneic catfish were allowed to grow in ponds for 3 years until they reached sexual maturity. Putative xenogeneic channel catfish males harboring sperm of blue catfish were paired and mated to normal channel female in aquaria following LHRHa injection of both fish at a dosage rate of 100 mg/kg of fish.

One xenogeneic male from the sub-adult treatment successfully spawned twice, but produced only 3 and 21 progeny, respectively. The putative xenogeneic fish from the blastula treatment have yet to produce a viable spawn. Three xenogeneic males from the fry treatment produced hybrid spawns with high fertility. One paired twice to two different channel females resulted in 20% fertility of the egg mass and the other two males spawned and the resulting egg masses were 100% fertile (Table 1).

PCR results for the progeny produced from the semi-natural spawning of putative xenogeneic channel males paired to normal channel females confirmed genotype to be that of channel catfish x blue catfish hybrids. This is the first report of large-scale, 100% hybrid production using xenogenesis. The production of xenogeneic brood stock must be improved for commercial scale production of brood stock.