COMPARISON OF CARP PITUITARY EXTRACT, CATFISH PITUITARY EXTRACT, OR LHRHA FOR INDUCED SPAWNING OF CHANNEL CATFISH FEMALES TO PRODUCE CHANNEL CATFISH X BLUE CATFISH HYBRID FRY

Authors: Bosworth, Brian

Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2004
Publication Date: 1/17/2005
Citation: Bosworth, B.G. 2005. Comparison of carp pituitary extract, catfish pituitary extract, or lhrha for induced spawning of channel catfish females to produce channel catfish x blue catfish hybrid fry. Aquaculture America Conference 2005, New Orleans, LA. Jan. 17-20, pp.386.

Interpretive Summary:

Technical Abstract: Channel catfish x blue catfish hybrids have improved growth, disease resistance, and meat yield compared to channel catfish. However, production of hybrid fry requires hormone induced spawning of female channel catfish. Objectives of this study were to compare efficacy of carp pituitary extract, catfish pituitary extract, and LHRHa for inducing ovulation in female channel catfish for production of channel x blue catfish fry. Mature female catfish were injected with carp pituitary extract, catfish pituitary extract, or LHRHa. Injection regimes were 2mg/kg female body weight (BW) initial injection and 8mg/kg 20 h later for carp and catfish pituitary extract or 40 ug/kg female BW initial injection followed by 80ug/kg 20 h later for LHRHa. Females were checked for ovulation 24 h following the final injection. Ovulating females were tranquilized and eggs were manually stripped into Hank’s Buffered Salt Solution. Eggs were weighed and then fertilized with blue catfish sperm. Egg masses were placed in hatching troughs and percent viable embryos was determined at 48 h post-fertilization. Fry numbers at hatch were estimated volumetrically. Data collected for each treatment included: weight of females injected, percent of injected females that ovulated, fecundity (# of eggs/kg female), percent viable embryos at 48 h, fry/kg female for all females injected, fry/kg weight of ovulated females, and total fry. Treatment means were compared by mixed model ANOVA. There were no differences among treatments for any of the variables measured. Results demonstrate that catfish pituitary extract was as effective as carp pituitary extract or LHRHa for inducing ovulation in channel catfish females.