Progress 09/01/15 to 08/31/19
Outputs
Target Audience:Graduate, undergraduate, and high school students, fish farmers, scientists, and the general public. Changes/Problems:A change was made in the methods for identification of single nucleotide polymorphism (SNP) markers for investigation of genetic variability of tilapia strains (Objective 2). Instead of DNA microarray technology, which was planned initially, SNP markers were identified using the more advanced restriction site associated DNA sequencing (RAD-Seq) technology. What opportunities for training and professional development has the project provided?This project provided an opportunity for high school, undergraduate, and graduate students to obtain basic knowledge on the principles of raising fish in a recirculating water system, fish spawning, and biological and mechanical water cleaning. How have the results been disseminated to communities of interest?Descriptions of this project and information on its progress have been presented to fish farmers and scientists at numerous conferences, meetings, field days, and workshops. Demonstrations about the raising of tilapia in water recirculating systems have been presented at numerous tours by high school students, farmers, and the general public. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
For Objective 1, growth rate of four tilapia crosses of YY males and XX females of different strains was compared. YY males from two strains and XX females from three strains were used for production of crosses. All four crosses were obtained at the same time and raised for 78 days in recirculation water systems under the same conditions. Then, fish were stocked in a recirculating system with 12 946-liter (250-US gallon) tanks for comparisons during the grow-out phase of raising. Each cross was raised in three replicated tanks and 50 fish were stocked per tank. Mean weight of stocked fish in crosses varied from 17.5 g to 21.4 g. During the 166-day raising period, fish were fed 2-3 times per day to apparent satiation; water temperature was maintained at 28°C. Based on results of comparisons during the grow-out phase of raising, one cross with a superior growth rate was identified. This cross was obtained using females from the Genetically Improved Farmed Tilapia (GIFT) strain. The growth rate of fish from this cross surpassed growth rates of other crosses by 58% or more; final mean weight of fish from this cross was 702.4 g while final mean weights of fish from three other crosses varied from 402.4 g to 447.0 g. Daily growth rate of fish from this cross was 4.1 g/d while this parameter in fish from the three other crosses was in the range of 2.3-2.6 g/d. Feed conversion ratio (FCR; ratio of fish weight gain to weight of consumed feed) for the cross with the superior gross rate (1.47) did not differ significantly from FCRs for two other crosses (1.46 and 1.48). This showed the advantage of this cross with regard to growth rate resulted from more aggressive feeding behavior of the fish and consumption of larger amount of feed. The tilapia cross with superior growth rate can be considered as the best for raising in recirculating systems. Raising of this cross will give farmers the opportunity to obtain fish of market size in a much shorter time compared with raising fish with lower growth rates. For Objective 2, investigation of genetic variability of eight tilapia strains using single nucleotide polymorphism (SNP) genetic markers was performed. For this purpose, a panel of approximately 31,800 SNPs have been developed using restriction site associated DNA sequencing (RAD-Seq) technology. Three YY-male and five mixed-sex strains available in the United States were investigated. In frame of this study, the rate of both intra- and interstrain variation were determined. Mean expected heterozygosity ranged from a low of 0.084 in the Miami YY strain to a high of 0.222 in the Miami mixed-sex strain. Two of the three YY groups (Miami YY strain and Fishgen YY Red strain) had the lowest expected heterozygosities (0.084 and 0.085, respectively) and second and third lowest observed heterozygosities (both 0.107). The number of private alleles varied from 90 to 3795 in different strains and tended to increase with increasing expected heterozygosity. Inbreeding, as measured by Fis (inter-individual fixation index or coefficient of inbreeding), was low in all populations, ranging from -0.060 in the Fishgen YY Dark strain to 0.04 in the GIFT (Genetically Improved Farmed Tilapia) strain. This indicates that the analyzed strains are currently being maintained with approximately random mating of individuals. Genetic differentiation between strains, as measured by Fst (subpopulation fixation index), ranged from little differentiation (Fst = 0.06 for the Ismailia Canal and GIFT strains) to strong differentiation (Fst = 0.32 for the Miami YY and Lake Manzala strains). The intermediate value of F (0.15) was detected between parental strains (Miami YY males and GIFT females) used for production of the cross with the superior growth rate (as demonstrated by results of comparative raising performed for Objective 1). For Objective 3, sex ratios in eight progenies obtained by seven crosses of YY males and XX females of different origin were investigated. The percentage of males in progenies varied from 79 to 100% with a mean value of 90.5%. The observed range of frequency of males in crosses of YY males with XX females was similar to reports from the literature on this parameter. As a result of this study, the crosses with highest proportion of males have been identified. The results of the study showed that YY tilapia males of the same origin could produce different percentages of males in crosses with females from different strains. The percentages of males in different progenies of the same cross could also differ. For Objective 4, color variability was investigated in eight progenies obtained by seven different crosses of YY males and XX females of different origins. Analysis of color variability and inheritance showed that body color (dark or red) in tilapia is determined by one gene with two alleles (R/r); a dominant allele (R) caused a red body color while a recessive allele (r) caused a dark (wild type) body color. These results coincided with previous data on color inheritance in Nile tilapia. Crosses red fish x red fish and red fish x dark fish performed in this study produced only red fish; the absence of dark fish in obtained progenies indicated that the parental genotypes in these crosses were RR x RR or RR x Rr. Crosses of dark fish (rr x rr) gave only dark fish (genotype rr) in progenies as expected. We also found that fish with a red background color can develop black spots and patches on the body. The rate of body coverage with black pigment was variable; apparently this trait is polygenic and has a complex mode of inheritance.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Delomas, T. A., Gomelsky, B., Vu, N., Campbell, M.R. and N.D. Novelo. 2019. SNP discovery and genetic variation in YY-male and mixed sex strains of Nile tilapia Oreochromis niloticus available in the United States. North American Journal of Aquaculture, 81:183-188.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2020
Citation:
Novelo, N. D., Gomelsky, B., Coyle, S.D. and A. G. Kramer. Growth, sex segregation, sexual dimorphism and color variability in Nile Tilapia crosses of YY males with normal females of different strains. Journal of the World Aquaculture Society, submitted.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Novelo, N.D., Gomelsky, B., Coyle, S.D. and A. G. Kramer. Evaluation of growth and sex segregation in Nile Tilapia crosses of YY males with normal XX females of different origin. Presented at World Aquaculture Society Conference Aquaculture 2019, New Orleans, LA, USA, March 7-11, 2019.
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Progress 09/01/17 to 08/31/18
Outputs
Target Audience:Graduate and undergraduate students, high school students, fish farmers, scientists, and the general public. Changes/Problems:A change was made in the methods for identification of Single Nucleotide Polymorphisms (SNPs) markers for investigation of genetic variability of tilapia strains. Instead of DNA microarray technology, which was planned initially, SNPs markers were identified using the more advanced Restriction Site Associated DNA Sequencing (RAD-seq) technology. What opportunities for training and professional development has the project provided?In the reporting period, this project provided an opportunity for high school, undergraduate, and graduate students to obtain basic knowledge on the principles of raising fish in a recirculating water system, fish spawning, and biological and mechanical water cleaning. How have the results been disseminated to communities of interest?Descriptions of this project and information on its progress have been presented on several occasions to fish farmers and scientists. Demonstrations about the raising of tilapia in water recirculating systems have been presented at numerous tours by high school students, farmers, and the general public. What do you plan to do during the next reporting period to accomplish the goals?For Objectives 1, 3 and, 4, the obtained data will be analyzed and reported in presentations and articles. For Objective 2, analysis of genetic variability of tilapia strains will be continued and completed.
Impacts
What was accomplished under these goals?
For Objective 1, four tilapia crosses of YY males and XX females of different strains were compared. YY males from two strains and XX females from three strains were used for production of crosses. All four crosses were obtained at the same time. Each cross was raised for 166 days in three replicated 250-gallon tanks in one recirculating system. One cross with superior growth rate was identified. This cross was obtained using females from Genetically Improved Farmed Tilapia (GIFT) line and the growth rate surpasses other crosses by 58% or more. This highly-productive tilapia cross can be considered the best for raising in recirculating systems. For Objective 2, the analysis of genetic variability of eight tilapia strains using Single Nucleotide Polymorphisms (SNPs) genetic markers is in progress. For this objective, a panel of approximately 30,000 SNPs have been developed using Restriction Site Associated DNA Sequencing (RAD-Seq) technology. For Objective 3, sex ratios in eight progenies obtained by seven crosses of YY males and XX females of different origins have been investigated. The percentage of males in progenies varied from 79 to 100% with a mean value of 90.5%. This demonstrated that YY tilapia males of the same origin could produce different percentages of males in crosses with females from different lines. The percentages of males in different progenies of the same cross could also differ. For Objective 4, color variability was investigated in eight progenies obtained by seven different crosses of YY males and XX females of different origins. Analysis of color variability and inheritance showed that background body color (dark or red) in tilapia is determined by one gene with two alleles; a dominant allele causes a red background color while recessive allele causes a dark body color. Crosses of the red background color x red background color and red background color x dark color produced only fish with a red background color while crossing dark fish resulted in appearance of dark offspring only. We also found that tilapia with a red background color can develop black spots and patches on the body. Coverage with black pigment on the red body is very variable and apparently this trait is polygenic with a complex mode of inheritance.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Novelo, N. D., Gomelsky, B., Coyle, S. D., Warner, J. L., and A. G. Kramer. 2018. Sex and color segregations in Nile tilapia crosses obtained from different strains of YY males and normal XX Females. Presented at Aquaculture America Conference, Las Vegas, Nevada, USA, February 19-22,2018.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Gomelsky, B., Novelo, N.D., Coyle, S.D., Kramer, A.G., and J.L. Warner. 2018. Growth rate and sex segregation in Nile tilapia crosses obtained using YY males and normal XX females of different origin. Presented at World Aquaculture Society Conference 'AQUA 2018', Montpellier, France, August 25-29, 2018.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Novelo, N. D. 2018. Tilapia Hatchery and Production. Presented at Workshop on Sustainable Agriculture, Harold R. Benson Research and Demonstration Farm, Kentucky State University, Frankfort, KY, June 21, 2018.
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Progress 09/01/16 to 08/31/17
Outputs
Target Audience:Graduate and undergraduate students, high school students, fish farmers, scientists, and the general public Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?In the reporting period this project provided opportunity for high school, undergraduate, and graduate students to obtain basic knowledge on principles of raising fish in recirculating water system, fish spawning and biological and mechanical water cleaning. How have the results been disseminated to communities of interest?Description of this project and information on its progress have been given in different presentations to fish farmers and scientists. Raising of tilapia in water recirculating systems has been demonstrated in numerous tours by high school students, farmers, and the general public. What do you plan to do during the next reporting period to accomplish the goals?The trial on comparisons of different tilapia inter-line crosses will continued and be completed. Based on results of this trial, the cross with the best growth rate will be identified. Analysis of raised inter-line crosses will be continued with regards to sex ratios and color inheritance. Genetic variability of tilapia lines used in crosses will be evaluated by the analysis of DNA genetic markers.
Impacts
What was accomplished under these goals?
For Objective 1, a trial comparing four tilapia crosses of YY males with females of different lines has started. Fish are raised in a recirculating water system with three replicates for each cross. This trial will continue until fish reach market size. For Objective 2, fin clip samples from YY males of three different lines and from normal XX females of five different lines have been collected for further analysis of DNA genetic markers. Equipment and laboratory supplies needed for this analysis have been identified and some have been acquired to date. For Objectives 3 and 4, eight crosses of YY males and XX females of different lines have been obtained for analysis. Fish from four inter-line crosses have been analyzed and preliminary data on sex ratios (Objective 3) and color variability (Objective 4) were obtained. The percentage of males in crosses varied from 88 to 100%; it was shown YY tilapia males of the same origin could produce different percentage of males in crosses with females from different lines. Crosses of solid red fish (no black pigmentation) resulted in appearance of both solid red fish and fish with a background red color covered with varying amounts of black patches. Crossing of two lines with dark color produced progenies only with a dark color. Four additional inter-line tilapia crosses will also be analyzed.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Gomelsky B. Application of crossbreeding and genetic sex regulation for development of fast-growing all-male tilapia cross for aquaculture. Poster presentation at USDA Capacity Building Grants (CBG)Program Project Directors' Meeting, Virginia Beach, VA, September 19-20, 2016.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2017
Citation:
Novelo N and B. Gomelsky. Hatchery production and genetics of tilapia. Oral presentation at Indoor Tilapia, Shrimp and Aquaponics Program at Kentucky State Universitys Aquaculture Research Center, March 25th, 2017.
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Progress 09/01/15 to 08/31/16
Outputs
Target Audience:Graduate and undergraduate students, fish farmers, high school students, scientists, general public Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?In the reporting period this project provided opportunity for graduate and graduate students to obtain basic knowledge on principles of raising fish in recirculating water systems, biological and mechanical water cleaning andwater chemistry. How have the results been disseminated to communities of interest?Raising of tilapia in water recirculation system has been demonstrated to numerous tours by high school students, farmers and general public. What do you plan to do during the next reporting period to accomplish the goals?Several tilapia crosses will beproduced bybreeding of YY-males with females of two different lines. Obtained crosses will be raised in recirculating water systems and their comparative viability and growth rate will be evaluated. Preliminary data on color variability and sex ratio of fish in crosses will be obtained. Single nucleotide polymorphism identified byDNA microarray technologywill be used to evaluate genetic variability of different tilapia lines.
Impacts
What was accomplished under these goals?
For accomplishment of Objective 1 two mix-sex tilapia lines have been acquired and raised in water recirculating systems. When females of these lines will reach sex maturity and appropriate size they will be bred with YY-males for production of different crosses. These tilapia crosses will be evaluated later in the frame of this project. Also, during reported period two groups of YY males (dark and red) have been raised in recirculating systems. For accomplishment of Objective 2 scientists and professionals have discussed the optimal ways of analysis;equipment and supplies foracquiring needed for fulfilment of this objective have been identified. Data on fish sex ratios (Objective 3) and fish color variability (Objective 4) will be obtained later when different crosses of tilapia will be obtained and raised. During reporting period Research Associate was selected and hired.
Publications
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