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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #216003
Title: ENDOCRINE RESPONSES OF FAST AND SLOW GROWING FAMILIES OF CHANNEL CATFISH ICTALURUS PUNCTATUS

Author
item Peterson, Brian
item Small, Brian
item Waldbieser, Geoffrey - Geoff
item Bosworth, Brian

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2007
Publication Date: 7/18/2007
Citation: Peterson, B.C., Small, B.C., Waldbieser, G.C., Bosworth, B.G. 2008. Endocrine responses of fast and slow growing families of channel catfish. North American Journal of Aquaculture 70:240-250.

Interpretive Summary: Fast and slow growing USDA303 catfish were grown to see if genes associated with the growth regulatory and stress axes could be used to describe differences in growth performance. Fish (59.0 +/- 2.4 g) were fed for 7 wks, weighed, and tissues were taken for RNA extraction. The remaining fish were subjected to a 10-min confinement stress. Insulin like growth factor-II mRNA was higher in muscle of fast growing compared to slow growing fish while all other genes tested were similar. Cortisol levels were negatively correlated to weight gain. These results suggest that variation in growth among fast and slow growing USDA303 catfish is explained, in part, by variation in the GH-IGF and stress axes. The relationship between cortisol and weight gain warrants further investigation for possible exploitation into our selective breeding program.

Technical Abstract: Sixty-eight families of USDA303 channel catfish were evaluated for growth performance for 30 days. The four fastest and four slowest growing catfish were further evaluated to examine the hypothesis that genes or gene products associated with the growth regulatory and stress axes could be used to describe differences in growth performance. Research examined mRNA levels of genes involved in the growth hormone-insulin like growth factor (GH-IGF) network in fast (Family A) and slow (Family H) growing USDA303 catfish. Fish (59.0 +/- 2.4 g) were fed for 7 wks, weighed, and tissues were taken for RNA extraction. The remaining fish were subjected to an acute 10-min confinement stress. IGF-II mRNA was higher (P < 0.05) in muscle of fast growing compared to slow growing fish while levels of IGF-I receptor (IGF-IR) and IGF-IIR were similar. IGF-IIR mRNA was two-fold higher in the muscle compared to muscle IGF-IR mRNA. IGF-I and GH receptor mRNA in the liver and muscle were similar while pituitary GH mRNA was also similar. Fast growing fish consumed 135% more feed compared to slow growing fish, however abundance of ghrelin mRNA in the gut and neuropeptide Y mRNA in the hypothalamus were similar. Cortisol levels were negatively correlated (r = -0.47; P < 0.05) to weight gain. These results suggest that variation in growth among fast and slow growing USDA303 catfish is explained, in part, by variation in the GH-IGF and stress axes. The relationship between cortisol and weight gain warrants further investigation for possible exploitation into our selective breeding program.