Location: Warmwater Aquaculture Research Unit
Title: Making A Better Hybrid Catfish: Can Hybridization of Channel Catfish Selected for ESC Resistance Improve Disease Resistance? Authors
Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 23, 2009
Publication Date: March 1, 2010
Citation: Chatakondi, N.G., Bosworth, B.G., Peterson, B.C., Booth, N.J. 2010. Making A Better Hybrid Catfish: Can Hybridization of Channel Catfish Selected for ESC Resistance Improve Disease Resistance?. 2010 Aquaculture America Conference. p. 183. Technical Abstract: Improved production traits such as disease resistance and growth have long been realized from the hybridization of channel catfish (Ictalurus punctatus) female X and blue catfish (Ictalurus furcatus) male. Recent advances in hybrid embryo production technology to consistently produce higher number of hybrids have advanced the adoption of this fish in the catfish industry. Hybridization of select lines of channel catfish with blue catfish is currently being addressed at the USDA Catfish Genetics Research Unit, Stoneville, MS, USA as a means of improving catfish production efficiency. One of the lines of channel catfish being developed is a line of fish with improved resistance to enteric septicemia of catfish (ESC), a disease that has great economic importance to the industry. In the current study, nine mature female channel catfish selected for ESC resistance (Resistant) strain and nine mature non-select or (Control) strain of channel catfish were induced to spawn (2+8 mg common carp pituitary extract/kg) in spring 2009. After 52 h of latency period, eggs from channel catfish (select and control strain) were hand stripped, quality and quantity of eggs measured, a portion of the eggs were fertilized with blue catfish sperm (pooled from 2-3 blue catfish males) to produce hybrid catfish and the other portion of eggs were fertilized with channel catfish sperm (pooled from 2-3 channel catfish males) to produce channel catfish. Eggs masses (hybrid and channel) from resistant and control families were labeled and hatched in baskets suspended in individual 80 L aquaria supplied with 27 ºC geothermal water and air. Chemical treatments of eggs and fry maintenance were based on protocols established at our facility. Reproductive performance of resistant and normal strain (Table 1) did not differ (P>0.05) Half-sib hybrid and channel catfish families produced by resistant and control strain of channel catfish will be challenged with ESC in replicated aquaria to determine the effects of genetic groups (channel vs hybrid) and the female strain (resistant vs normal) to ascertain the superiority of hybrid catfish. Another study will be conducted in 1200 L tanks supplied with flow through pond water and air to evaluate the performance (growth and disease resistance) of hybrid and channel families. Results from these studies and future research on improving the performing of hybrids will be discussed. Table 1. Channel catfish (Normal) and ESC resistant (Resistant) strains of channel catfish were induced to spawn with 2+8 mg of common carp pituitary extract/kg of body weight at 15 h intervals and fertilized with either blue catfish sperm (hybrids) or channel catfish sperm (channels). Reproductive performance of resistant and normal strain did not differ (P>0.05).