Submitted to: Catfish Culture Research Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2003
Publication Date: 2/21/2003
Citation: Small, B.C., Wolters, W.R., Bates, T.D. 2003. Management strategies for improved hatching success. Proc. 2003 Catfish Culture Research Symposium-Catfish Farmers of America Annual Meeting, Sandestin, FL, p. 19.
Technical Abstract: Hatching success of individual channel catfish spawns varies greatly in both commercial and research hatcheries, ranging from 0-100%. Environmental factors affecting hatching success can be addressed through understanding the development of catfish embryos and optimizing management practices to improve environmental conditions and reduce disease. Several experiments were conducted to determine the effects of temperature, transport, hardness, and chemotherapeutics on hatching success and embryo development. The results indicate hatching success to be highest between 79 and 83 degrees Fahrenheit. Extended delays (>30 min.) in transporting eggs to the hatchery were shown to significantly lower hatching success by 10-30%. Low water hardness (<10 mg/L as CaCO3) was found to have a significant negative effect on hatching success. Eggs without supplemental calcium during the first 24 hours post-fertilization had a 72% lower hatch rate. No direct correlation between water hardness and development of triple-tail or other deformities could be established; however, preliminary results suggest physical damage or shock during embryo development may play a role in the induction of tripletail. Improved hatching success, a 30% increase over iodine bath alone, was achieved by conducting once daily hydrogen peroxide baths (250 mg/L) for 15 minutes until eyed to control egg infections. The optimal concentration for daily hydrogen peroxide treatments in 100 gallon flow-through hatching troughs was determined to be 70 mg/L, yielding a 60% improvement in hatching success compared to untreated eggs from the same spawns. This research shows that small improvements to current management practices can significantly increase channel catfish hatching success; a 30% improvement could mean over 400 million more fry annually.