MASTERS IN AQUACULTURE AND FISHERIES Genetics and Selection Part 1 I ntroduction to the Course...

MASTERS IN AQUACULTURE AND FISHERIES Genetics and Selection

Part 1Introduction to the

Course

–The relevance of genetics and selection for aquaculture and fisheries;–Present status of the Industry–Assessment of knowledge

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A BRIEF HISTORY OF GENETICS AND SELECTION OF AQUATIC ORGANISMS

• Over 2000 years ago the Chinese and the Romans had started growing fish, mainly carp, and selecting the best varieties;

• In the 1800s the Japanese developed dozens of varieties of Koi Carp through artificial selection;

• In the 1960s started the first genetic enhancement programs in aquatic organisms;

• Since the 1980s molecular tools and biotechnology have been applied to support traditional selection methods and developing new ones;


The Chinese and the Carp


Japan in the 1800s… Koi Carp Varieties


Relevance of Genetics and Selection to the Aquaculture Industry

• At present 10%-20% of fish and shellfish produced in aquaculture derive from domesticated/selected stocks;

• Practically all other food sources for human consumption (meat, poultry, vegetables) are the product of decades of selection and genetic improvement;


Results of Selection Programs in Land Animal Species

• Since the 1940’s, the average number of eggs laid per year by a hen has increased from 120 to more than 320;

• The average milk production per cow in single lactation of 305 days increased from 2,000 kgs to over 5,000 kgs;

• The average daily gain in the pig industry has increased from 450 grams to over 800 grams (in the last 30 years).


Results of Selection Programs in Fish Species

• For salmon, phenotypic and genetic selection has reduced time to achieve market weight by over 30% with a parallel decrease of maintenance requirements (feed, labor, fuel, etc.) by over 25%.


The Production Advantages of Selected Fish and Shellfish Stocks

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The Production Advantages of Selected Fish and Shellfish Stocks

• Through selection fish and shellfish will be:– Cheaper to produce;– Each Kg produced will require less feed – Savings

on resources;– The environmental impact of producing fish will be

reduced (per Kg of fish produced);– Aquaculture will become a viable industry;


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0,00,51,01,52,02,53,03,54,04,55,05,56,06,57,07,5

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Production Average Value

The Problem…


What do Fish farmers Want from Genetics and Selection of Livestock?

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What do Fish farmers Want from Genetics and Selection of Livestock?

• CIHEAM study – 1998 - Most important characters to select:

– Growth rate / FCR;– Disease resistance;– Body conformation;– Stress resistance;– Age at maturity;


Current Status of the Application of Selection and Genetics to the Industry:

1 - What can be done• A number of target characters (e.g. growth rate) have

been shown to have great potential for genetic improvement – shown in the laboratory or in pilot selection experiments;

• Most aquaculture species have high fecundity which allows for very high short-term genetic gains through intense and accurate selection;

• For most of the important species there are available genetic markers (mtDNA, microsatellite) and for many genetic maps and QTL-maps are becoming available



2 – What are we doing?

• There are at present (Gjerde and Villanueva, 2003) 27 selection programs operation in the world, involving 9 species;

• Most use traditional designs and technologies, with some exceptions such as the use of electronic PIT tags and to a small extent PCR amplification of microsatellites for pedigree analysis;

• Most farmers still rely of wild genetic stocks



3 – Why?

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3 – Why?• Lack of knowledge;• Lack of patience;• Lack of money;• Lack of infrastructure;• Lack of organization

– National aquaculture associations;– Companies;– Universities – industry associations;


Our Knowledge Pool…

• Populations and individuals;• Cells, Nuclei, Chromosomes, polyploidy, haploid;• mtDNA, genes, minisatellites, microsatellites, QTLs,

QTL maps, RFLP, Enzyme electrophoresis, AFLPs, DNA sequences;

• Family selection, within family selection, mass selection;

• Gene Pool, selection pressure, selection response;• Heritabilty (h2), VA, VE, VP

• Mean, Variance


Home Work…

• www site check: http://www.4cshellfish.com/index.html• Paper reviews:

– Boudry et al. 1998. Genetic improvement and selection in shellfish: A review based on oyster research and production. In Bartley, D.M. (ed.), Basurco B. (ed.) Genetics and breeding of Mediterranean aquaculture species Zaragoza : CIHEAM-IAMZ, 1998. 296 p. (Cahiers Options Méditerranéennes ; v. 34). Seminar of the CIHEAM Network on Technology of Aquaculture in the Mediterranean (TECAM), 1997/04/28-29, Zaragoza (Spain)

– Felip, A, et al., 2001. Comparative growth performance of diploid and triploid European sea bass over the first four spawning seasons. J Fish Biol, 58:76-88

– Felip et al., 2002. Growth, gonadal development and sex ratios of meiogynogenetic diploid sea bass. J Fish Biol, 61:347-359

MASTERS IN AQUACULTURE AND FISHERIES Genetics and Selection Part 1 I ntroduction to the Course...

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