Cooperative and uniform fish? : social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia

H.L. Khaw

Research output: Thesisinternal PhD, WUAcademic

Abstract

Abstract

Khaw, HL. (2014). Cooperative and uniform fish? Social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. PhD thesis, Wageningen University, the Netherlands.

Social interactions are present everywhere in the living world. Such social interactions may lead to indirect genetic effects (IGE), which are heritable effects of an individual on trait values of the other individuals its interacts with. IGEs may affect the direction and magnitude of response to selection in breeding programs. Moreover, social interactions may affect variability of traits. In aquaculture, competition for resources inflates size variation within populations. In this thesis, we used the Genetically Improved Farmed Tilapia (GIFT; Oreochromis niloticus) strain to investigate the genetic basis for social interactions and variability in harvest weight for tropical finfish. Social interaction experiments were established for quantifying the genetic and non-genetic indirect effects on harvest weight in the GIFT strain. We found evidence for IGEs on harvest weight, and a negative direct-indirect genetic correlation, which suggesting heritable competitive interactions for harvest weight in GIFT. Hence, breeding schemes may need to be adapted to avoid an increase in competition. A stochastic simulation study was conducted to examine the effect of BLUP selection on the rate of inbreeding for socially affected traits. The rates of inbreeding for scenarios with IGEs were greater than for scenarios without IGE. Therefore, with IGEs there is a greater need for a selection algorithm that restricts the increase of mean kinship. In aquaculture industry, there is a wide range of commercial production environments, which may leads to genotype by environment (GxE) interaction, for example due to differential social interactions. The GIFT fish were tested in ponds and cages to study the GxE interaction. The genetic correlations between environments (0.73 to 0.85, for harvest weight and body measurements) indicate little GxE-interaction. The data collected from the social interaction experiments were also used to investigate the presence of genetic variation in uniformity for harvest weight. The genetic coefficient of variation for standard deviation of harvest weight (0.17) shows that uniformity of harvest weight is heritable and can be increased by selective breeding. In the General Discussion of this thesis, the uniformity study was extended to incorporate IGE. The result indicates that more cooperative fish are not necessary more uniform for harvest weight. Overall, our results suggest that genetic improvement in fish breeding programs can be increased by accounting for social interactions.

 

LanguageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • van Arendonk, Johan, Promotor
  • Bijma, Piter, Co-promotor
  • Ponzoni, R.W., Co-promotor, External person
Award date13 Jan 2015
Place of PublicationWageningen
Publisher
Print ISBNs9789462572157
Publication statusPublished - 2015

Fingerprint

Oreochromis niloticus
Malaysia
cooperatives
body weight
fish
inbreeding
genetic correlation
breeding
Tilapia (Cichlidae)
body measurements
kinship
selection methods
genetic improvement
aquaculture
Netherlands
cages
genetic variation
genotype

Keywords

  • oreochromis niloticus
  • social behaviour
  • body weight
  • variation
  • genetic effects
  • inbreeding
  • traits
  • heritability
  • genotype environment interaction
  • genetic variance
  • genetic improvement
  • breeding programmes
  • fish culture
  • malaysia

Cite this

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title = "Cooperative and uniform fish? : social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia",
abstract = "Abstract Khaw, HL. (2014). Cooperative and uniform fish? Social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. PhD thesis, Wageningen University, the Netherlands. Social interactions are present everywhere in the living world. Such social interactions may lead to indirect genetic effects (IGE), which are heritable effects of an individual on trait values of the other individuals its interacts with. IGEs may affect the direction and magnitude of response to selection in breeding programs. Moreover, social interactions may affect variability of traits. In aquaculture, competition for resources inflates size variation within populations. In this thesis, we used the Genetically Improved Farmed Tilapia (GIFT; Oreochromis niloticus) strain to investigate the genetic basis for social interactions and variability in harvest weight for tropical finfish. Social interaction experiments were established for quantifying the genetic and non-genetic indirect effects on harvest weight in the GIFT strain. We found evidence for IGEs on harvest weight, and a negative direct-indirect genetic correlation, which suggesting heritable competitive interactions for harvest weight in GIFT. Hence, breeding schemes may need to be adapted to avoid an increase in competition. A stochastic simulation study was conducted to examine the effect of BLUP selection on the rate of inbreeding for socially affected traits. The rates of inbreeding for scenarios with IGEs were greater than for scenarios without IGE. Therefore, with IGEs there is a greater need for a selection algorithm that restricts the increase of mean kinship. In aquaculture industry, there is a wide range of commercial production environments, which may leads to genotype by environment (GxE) interaction, for example due to differential social interactions. The GIFT fish were tested in ponds and cages to study the GxE interaction. The genetic correlations between environments (0.73 to 0.85, for harvest weight and body measurements) indicate little GxE-interaction. The data collected from the social interaction experiments were also used to investigate the presence of genetic variation in uniformity for harvest weight. The genetic coefficient of variation for standard deviation of harvest weight (0.17) shows that uniformity of harvest weight is heritable and can be increased by selective breeding. In the General Discussion of this thesis, the uniformity study was extended to incorporate IGE. The result indicates that more cooperative fish are not necessary more uniform for harvest weight. Overall, our results suggest that genetic improvement in fish breeding programs can be increased by accounting for social interactions.  ",
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Cooperative and uniform fish? : social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. / Khaw, H.L.

Wageningen : Wageningen University, 2015. 161 p.

Research output: Thesisinternal PhD, WUAcademic

TY - THES

T1 - Cooperative and uniform fish? : social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia

AU - Khaw, H.L.

N1 - WU thesis 5956

PY - 2015

Y1 - 2015

N2 - Abstract Khaw, HL. (2014). Cooperative and uniform fish? Social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. PhD thesis, Wageningen University, the Netherlands. Social interactions are present everywhere in the living world. Such social interactions may lead to indirect genetic effects (IGE), which are heritable effects of an individual on trait values of the other individuals its interacts with. IGEs may affect the direction and magnitude of response to selection in breeding programs. Moreover, social interactions may affect variability of traits. In aquaculture, competition for resources inflates size variation within populations. In this thesis, we used the Genetically Improved Farmed Tilapia (GIFT; Oreochromis niloticus) strain to investigate the genetic basis for social interactions and variability in harvest weight for tropical finfish. Social interaction experiments were established for quantifying the genetic and non-genetic indirect effects on harvest weight in the GIFT strain. We found evidence for IGEs on harvest weight, and a negative direct-indirect genetic correlation, which suggesting heritable competitive interactions for harvest weight in GIFT. Hence, breeding schemes may need to be adapted to avoid an increase in competition. A stochastic simulation study was conducted to examine the effect of BLUP selection on the rate of inbreeding for socially affected traits. The rates of inbreeding for scenarios with IGEs were greater than for scenarios without IGE. Therefore, with IGEs there is a greater need for a selection algorithm that restricts the increase of mean kinship. In aquaculture industry, there is a wide range of commercial production environments, which may leads to genotype by environment (GxE) interaction, for example due to differential social interactions. The GIFT fish were tested in ponds and cages to study the GxE interaction. The genetic correlations between environments (0.73 to 0.85, for harvest weight and body measurements) indicate little GxE-interaction. The data collected from the social interaction experiments were also used to investigate the presence of genetic variation in uniformity for harvest weight. The genetic coefficient of variation for standard deviation of harvest weight (0.17) shows that uniformity of harvest weight is heritable and can be increased by selective breeding. In the General Discussion of this thesis, the uniformity study was extended to incorporate IGE. The result indicates that more cooperative fish are not necessary more uniform for harvest weight. Overall, our results suggest that genetic improvement in fish breeding programs can be increased by accounting for social interactions.  

AB - Abstract Khaw, HL. (2014). Cooperative and uniform fish? Social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. PhD thesis, Wageningen University, the Netherlands. Social interactions are present everywhere in the living world. Such social interactions may lead to indirect genetic effects (IGE), which are heritable effects of an individual on trait values of the other individuals its interacts with. IGEs may affect the direction and magnitude of response to selection in breeding programs. Moreover, social interactions may affect variability of traits. In aquaculture, competition for resources inflates size variation within populations. In this thesis, we used the Genetically Improved Farmed Tilapia (GIFT; Oreochromis niloticus) strain to investigate the genetic basis for social interactions and variability in harvest weight for tropical finfish. Social interaction experiments were established for quantifying the genetic and non-genetic indirect effects on harvest weight in the GIFT strain. We found evidence for IGEs on harvest weight, and a negative direct-indirect genetic correlation, which suggesting heritable competitive interactions for harvest weight in GIFT. Hence, breeding schemes may need to be adapted to avoid an increase in competition. A stochastic simulation study was conducted to examine the effect of BLUP selection on the rate of inbreeding for socially affected traits. The rates of inbreeding for scenarios with IGEs were greater than for scenarios without IGE. Therefore, with IGEs there is a greater need for a selection algorithm that restricts the increase of mean kinship. In aquaculture industry, there is a wide range of commercial production environments, which may leads to genotype by environment (GxE) interaction, for example due to differential social interactions. The GIFT fish were tested in ponds and cages to study the GxE interaction. The genetic correlations between environments (0.73 to 0.85, for harvest weight and body measurements) indicate little GxE-interaction. The data collected from the social interaction experiments were also used to investigate the presence of genetic variation in uniformity for harvest weight. The genetic coefficient of variation for standard deviation of harvest weight (0.17) shows that uniformity of harvest weight is heritable and can be increased by selective breeding. In the General Discussion of this thesis, the uniformity study was extended to incorporate IGE. The result indicates that more cooperative fish are not necessary more uniform for harvest weight. Overall, our results suggest that genetic improvement in fish breeding programs can be increased by accounting for social interactions.  

KW - oreochromis niloticus

KW - sociaal gedrag

KW - lichaamsgewicht

KW - variatie

KW - genetische effecten

KW - inteelt

KW - kenmerken

KW - heritability

KW - genotype-milieu interactie

KW - genotypische variatie

KW - genetische verbetering

KW - veredelingsprogramma's

KW - visteelt

KW - maleisië

KW - oreochromis niloticus

KW - social behaviour

KW - body weight

KW - variation

KW - genetic effects

KW - inbreeding

KW - traits

KW - heritability

KW - genotype environment interaction

KW - genetic variance

KW - genetic improvement

KW - breeding programmes

KW - fish culture

KW - malaysia

M3 - internal PhD, WU

SN - 9789462572157

PB - Wageningen University

CY - Wageningen

ER -