Aquaculture America 2020

February 9 - 12, 2020

Honolulu, Hawaii

INDUCTION OF STERILITY IN HYBRID CRAPPIE Pomoxis annularis × P. nigromaculatus AND HYBRID CATFISH Ictalurus punctatus × I. furcatus

 
 Anita M. Kelly*, Nagaraj Chatakondi, Robert Glennon and Jeff Baxter
 Auburn University
 Alabama Fish Farming Center
 529 S. Centreville Street
 Greensboro, AL 36744
 amk0105@auburn.edu

Hybrids are produced for aquaculture and the recreational fishing industries. Black crappie (Pomoxis nigromaculatus) and white crappie (Pomoxis annularis) are popular panfish caught by anglers in the US. Hybrid crappie (P. annularis ♀ x P. nigromaculatus ♂) grow faster and weigh more than both the white crappie and the black crappie.  Hybrid crappie are stocked into ponds to obtain trophy sized fish quickly. One drawback to stocking crappie or hybrid crappie is that they do reproduce and in large numbers.  Recommendations for stocking white, black or hybrid crappie is to stock them in ponds greater than 25 acres.  This prevents overpopulation and enables the crappie to grow to reasonable sizes.  Hybrid catfish are the cross between a female channel catfish (Ictalurus punctatus) and a male blue catfish (I. furcatus ).  Hybrid catfish are produced commercial for the food fish market.  Hybrids grow faster than the channel or blue catfish, have higher survival rates and better meat yield than channel catfish. Hybrid catfish production constitutes approximately 70% of the catfish production in the US.  However, first-generation hybrid catfish can reproduce.  Triploid induction is a method used to induce functional sterility in fish. Triploid induction is some species will also increase the growth rates in hybrids which would enable less time to obtain trophy fish, as with the hybrid crappie, or less time to market-size, as with the hybrid catfish.  Hybrid crappie were subjected to pressure shocks to induce triploidy and stocked into ponds  (4000/acre)  to determine growth rates compared to hybrid crappie not subjected to a shock.  For hybrid catfish, fertilized eggs were subjected to heat shock to induce triploidy and stocked into ponds  (8,000/acre)  for growth rate comparisons to non-heat shocked hybrid catfish. Triploid hybrid crappie and hybrid crappie were feed trained prior to stocking into ponds.  All fish were fed 3% of their body weight per day and all groups were replicated four times. Growth rates, FCR, and gonad development were examined after one year. Survival rates for triploid  hybrid  crappie and triploid hybrid catfish were higher than those of the hybrid crappie and hybrid catfish. Reproductive function of the first-generation of offspring was significantly reduced with little viable sperm or eggs visible in the gonads.  This study demonstrated that triploid induction in hybrid crappie and hybrid catfish produced more offspring and that these offspring were sterile.