Progress 07/01/00 to 06/30/05
Outputs
1. To determine the testosterone, 11-ketotestosterone, 17B-estradiol, and cortisol hormone levels in sexually mature female and male channel catfish over a 12-month period. Blood samples have been taken on a monthly basis from 10 male and 10 females of four different strains of channel catfish since June 2000. Samples have been stored and analysed for estradiol, testosterone, and cathepsins. Vitellogenin is currently being analyzed with results being obtained by April 1, 2005. 2. To examine the effect of cortisol on female channel catfish steroidogenesis. This study was conducted by Dr. Brian Small at the National Warmwater Aquaculture Center. Rather than repeat the study, we substituted plasma vitellogenin and cathepsins for cortisol. 3. To correlate the hormonal levels to spawning success in females. This has been done data will be included in the dissertation of Marinela Barrero-Monzon.. 4. To examine eggs from ovulation until 5-d post ovulation to determine when
eggs become overripe. This was accomplished during spawning season 2001 and will was repeated during the spawning season in 2002. Eggs are known to become overripe within 48 hours. 5. To determine the stocking density that optimizes the number of female channel catfish spawning. The current stocking numbers of 1200 lbs of broodfish per acre is the upper limit of stocking that can be used prior to subsequent declines in spawning numbers. Broodfish stocked at 800-1000 lbs per acre provided the highest numbers of females spawning with 25% in 2001 and 27% in 2002.
Impacts
The outcome of this research has provided a better understanding of the spawning cycles of channel catfish. It appears that hormone cycles and egg quality are not major impediments to catfish spawning but that some other factor is contributing to the low spawning success. Future research will include examination of sperm quality, diet and environmental factors that may also contribute to low spawning success. This study will lead to a docotral dissertation for one student.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
(1) To determine the testosterone, 11-ketotestosterone, 17b-estradiol, and cortisol hormone levels in sexually mature female and male channel catfish over a 12-month period. Blood samples have been taken on a monthly basis from 10 male and 10 females since June 2000. Samples have been stored and analysis will be done once the all samples have been taken. Additionally, three other strains of channel catfish have been obtained and blood samples have been taken on a monthly basis from 10 male and 10 females since June 2001. Samples have been stored and analysis will be done once the all samples have been taken. (2) To examine the effect of cortisol on female channel catfish steroidogenesis. Thirty female channel catfish were injected with 10ug/kg cortisol and placed in three (10 fish per pond) 0.4 ha pond with five males each and allowed to spawn naturally. Controls were injected with a saline solution and placed into ponds at the same quantities as the test fish.
Progeny from the females injected with cortisol will be examined for stress responses at a later date. (3) To correlate the hormonal levels to spawning success in females. This was completed during spawning season 2001 and 2002, data still needs to be analyzed. (4) To examine eggs from ovulation until 5-d post ovulation to determine when eggs become overripe. This was done during spawning season 2001 and 2002. (5) To determine the stocking density that optimizes the number of female channel catfish spawning. This study was initially done during spawning season 2001, however the data helped to bracket potential stocking densities for optimization for spawning female channel catfish. The bracketed numbers were used to conduct the study again in Spring 2002. Preliminary data indicates that current industry stocking rates contribute to the decline in spawning success.
Impacts
The outcome of this research will provide a better understanding of the spawning cycles of channel catfish. Hormone levels as well as examination of egg maturity over a course of 2 or more years will give an indication of spawning frequency of females and males. This data combined with the new breakthroughs in identifying the gene that appears to be necessary for spawning to occur will help identify the frequency and strains of fish that spawn at regular intervals. It will also allow fingerling producers to maintain fewer broodfish in order to obtain the number of progeny needed.
Publications
- Kelly, Anita M. 2002. Broodfish management. C.S. Tucker and J.A. Hargreaves, editors. Elsevier, New York, N.Y. The Biology and Culture of Channel Catfish. In press.
- Kelly, Anita M. 2002. Channel catfish culture. A.M. Kelly and J. Silverstein, editors. Fish Culture Section, American Fisheries Society, Bethesda, MD. In Press.
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Progress 01/01/01 to 12/31/01
Outputs
(1) To determine the testosterone, 11-ketotestosterone, 17b-estradiol, and cortisol hormone levels in sexually mature female and male channel catfish over a 12-month period. Blood samples have been taken on a monthly basis from 10 male and 10 females since June 2000. Samples have been stored and analysis will be done once the all samples have been taken. Additionally, three other strains of channel catfish have been obtained and blood samples have been taken on a monthly basis from 10 male and 10 females since June 2001. Samples have been stored and analysis will be done once the all samples have been taken. (2) To examine the effect of cortisol on female channel catfish steroidogenesis. This is scheduled for Spring 2002. (3) To correlate the hormonal levels to spawning success in females. This was done during spawning season 2001, data still needs to be analyzed. (4) To examine eggs from ovulation until 5-d post ovulation to determine when eggs become overripe. This
was done during spawning season 2001 and will be repeated during the spawning season in 2002. (5) To determine the stocking density that optimizes the number of female channel catfish spawning. This study was initially done during spawning season 2001, however the data helped to bracket potential stocking densities for optimization for spawning female channel catfish. The bracketed numbers will be used to conduct the study again in Spring 2002.
Impacts
The outcome of this research will provide a better understanding of the spawning cycles of channel catfish. Hormone levels as well as examination of egg maturity over a course of 2 or more years will give an indication of spawning frequency of females and males.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
To determine the testosterone, 11-ketotestosterone, 17b-estradiol, and cortisol hormone levels in sexually mature female and male channel catfish over a 12-month period. Blood samples have been taken on a monthly basis from 10 male and 10 females since June 2000. Samples have been stored and analysis will be done once the all samples have been taken. To examine the effect of cortisol on female channel catfish steroidogenesis. This is scheduled to start Spring 2001. To correlate the hormonal levels to spawning success in females. This will be done during spawning season 2001. To examine eggs from ovulation until 5-d post ovulation to determine when eggs become overripe. This will be done during spawning season 2001. To determine the stocking density that optimizes the number of female channel catfish spawning. Broodfish for this experiment have been obtained. This study will be done during spawning season 2001.
Impacts
The outcome of this research will provide a better understanding of the spawning cycles of channel catfish. Hormone levels taken over a course of 2 or more years will give an indication of spawning frequency of females and males.
Publications
- No publications reported this period
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