Search

Selective breeding strategies require pedigree information over generations, but many species produced in aquaculture are too small to be physically tagged at early stages. Consequently, maintaining a sufficient number of separate families is often needed but costly and logistically difficult. Alternatively, parentage assignment can be obtained using DNA markers. We developed a panel of single nucleotide polymorphism (SNP) markers for the European abalone Haliotis tuberculata using an existing transcriptomic resource. An initial set of 2,176,887 SNPs was filtered to select 500 for high throughput genotyping. Of these, 298 SNPs were amplified in at least 90% of our H. tuberculata samples, consisting of a mixed family cohort (945 offspring) generated by crossing 40 abalones, and 5 full-sib training families (70 offspring). Based on amplification success among parents, minimum allele frequency and checks carried out against the training families, a subset of 123 markers was used to carry out parentage assignment in our mixed family cohorts. Maximum likelihood and exclusion-based methods of parentage assignment yielded consistent results, allowing parentage to be assigned in 98.9% of the studied progeny. Optimization of markers suggests that the 60 most informative SNPs may be sufficient for 95% assignment success in these progeny. The panel was also used to estimate effective population size, and revealed a low Ne due to high variance of reproductive success between parents. Our panel could be used to estimate genetic parameters of traits in mixed family cohorts, an essential stage to initiate selective breeding in H. tuberculata. It could also be useful tool in the context of monitoring stock enhancement and population genetics studies.

Selective breeding strategies require pedigree information over generations, but many species produced in aquaculture are too small to be physically tagged at early stages. Consequently, maintaining a sufficient number of separate families is often needed but costly and logistically difficult. Alternatively, parentage assignment can be obtained using DNA markers. We developed a panel of single nucleotide polymorphism (SNP) markers for the European abalone Haliotis tuberculata using an existing transcriptomic resource. An initial set of 2,176,887 SNPs was filtered to select 500 for high throughput genotyping. Of these, 298 SNPs were amplified in at least 90% of our H. tuberculata samples, consisting of a mixed family cohort (945 offspring) generated by crossing 40 abalones, and 5 full-sib training families (70 offspring). Based on amplification success among parents, minimum allele frequency and checks carried out against the training families, a subset of 123 markers was used to carry out parentage assignment in our mixed family cohorts. Maximum likelihood and exclusion-based methods of parentage assignment yielded consistent results, allowing parentage to be assigned in 98.9% of the studied progeny. Optimization of markers suggests that the 60 most informative SNPs may be sufficient for 95% assignment success in these progeny. The panel was also used to estimate effective population size, and revealed a low Ne due to high variance of reproductive success between parents. Our panel could be used to estimate genetic parameters of traits in mixed family cohorts, an essential stage to initiate selective breeding in H. tuberculata. It could also be useful tool in the context of monitoring stock enhancement and population genetics studies.

Selective breeding strategies require pedigree information over generations, but many species produced in aquaculture are too small to be physically tagged at early stages. Consequently, maintaining a sufficient number of separate families is often needed but costly and logistically difficult. Alternatively, parentage assignment can be obtained using DNA markers. We developed a panel of single nucleotide polymorphism (SNP) markers for the European abalone Haliotis tuberculata using an existing transcriptomic resource. An initial set of 2,176,887 SNPs was filtered to select 500 for high throughput genotyping. Of these, 298 SNPs were amplified in at least 90% of our H. tuberculata samples, consisting of a mixed family cohort (945 offspring) generated by crossing 40 abalones, and 5 full-sib training families (70 offspring). Based on amplification success among parents, minimum allele frequency and checks carried out against the training families, a subset of 123 markers was used to carry out parentage assignment in our mixed family cohorts. Maximum likelihood and exclusion-based methods of parentage assignment yielded consistent results, allowing parentage to be assigned in 98.9% of the studied progeny. Optimization of markers suggests that the 60 most informative SNPs may be sufficient for 95% assignment success in these progeny. The panel was also used to estimate effective population size, and revealed a low Ne due to high variance of reproductive success between parents. Our panel could be used to estimate genetic parameters of traits in mixed family cohorts, an essential stage to initiate selective breeding in H. tuberculata. It could also be useful tool in the context of monitoring stock enhancement and population genetics studies.

Farming, and thus the domestication of Haliotis tuberculata, began recently. We compared the responses of unselected farmed and wild abalone to stressors that occur on farms. The aim was to determine if the farm environment had induced differences in the behavioural or physiological performances of the abalone. Thirty hatchery-born 3.5 year-old abalone and thirty wild ones were reared under standard farm conditions for 6 months and characterised for 19 traits related to growth, survival, behaviour and immunology. Behavioural and immunological responses to stressors differed between the two stocks. Farmed abalone retracted and swivelled less in reaction to a finger contact. Phagocytosis efficiency was reduced by shaking in abalone from both origins, but the farmed stock returned to the basal level after the recovery week, while wild abalone did not, and a rise of total haemocyte count after shaking and its return to a basal level after one week was only observed for the farmed stock. This indicates that both behaviour and immune responses following a stress have been affected by the farming practices. This suggests that a domestication process has already been initiated in the farmed stock. Our results may also be important for the success of any population enhancement based on hatchery-produced abalone as they raise the question of the capacity of abalone with a farmed origin to be adapted to the wild environment.

Abalone growth rate is often identified among important traits to improve through selective breeding. However, the rapid success of some selective breeding plans has sometimes led to negative effects in some aquaculture species due to trade-offs. One of them is the loss of homeostasis of selected animals which results in the inability to resist the stress experienced during the rearing process. In this context, this study aimed to analyze the phenotypic relationships between growth, and physiological and behavioural traits in Haliotis tuberculata under stressful conditions. Eleven traits related to growth, immunity, reproduction and behaviour were recorded under laboratory conditions. A total of 120 adults from wild or farm origin were first monitored during a 3-week stress period (high density and acute stress handling) during winter, followed by 6 months on-growing in sea-cages. Relationships between parameters were analyzed using a multi-factorial approach. Wild and farm stocks could only be discriminated on behaviour traits, confirming that the French abalone industry is in the beginning of the domestication process. After 3 weeks of chronic stress, the righting latency of an abalone was linked to better survival and faster growth. Abalones having the best growth after 6 months were characterized by higher activity during the previous winter period, whereas an early gonad maturation reduced the growth in summer. Our results provide a basis for the establishment of a multi-trait breeding program to improve the growth rate while controlling the evolution of physiological and behavioural traits. Statement of relevance The relationships of behavioural and physiological variables with survival and weight gain after application of important stressors were studied in order to provide a better understanding of Haliotis tuberculata biology during early domestication stage. This paper will give information on new targets and tools for selective breeding.

Farming, and thus the domestication of Haliotis tuberculata, began recently. We compared the responses of unselected farmed and wild abalone to stressors that occur on farms. The aim was to determine if the farm environment had induced differences in the behavioural or physiological performances of the abalone. Thirty hatchery-born 3.5 year-old abalone and thirty wild ones were reared under standard farm conditions for 6 months and characterised for 19 traits related to growth, survival, behaviour and immunology. Behavioural and immunological responses to stressors differed between the two stocks. Farmed abalone retracted and swivelled less in reaction to a finger contact. Phagocytosis efficiency was reduced by shaking in abalone from both origins, but the farmed stock returned to the basal level after the recovery week, while wild abalone did not, and a rise of total haemocyte count after shaking and its return to a basal level after one week was only observed for the farmed stock. This indicates that both behaviour and immune responses following a stress have been affected by the farming practices. This suggests that a domestication process has already been initiated in the farmed stock. Our results may also be important for the success of any population enhancement based on hatchery-produced abalone as they raise the question of the capacity of abalone with a farmed origin to be adapted to the wild environment.

Abalone growth rate is often identified among important traits to improve through selective breeding. However, the rapid success of some selective breeding plans has sometimes led to negative effects in some aquaculture species due to trade-offs. One of them is the loss of homeostasis of selected animals which results in the inability to resist the stress experienced during the rearing process. In this context, this study aimed to analyze the phenotypic relationships between growth, and physiological and behavioural traits in Haliotis tuberculata under stressful conditions. Eleven traits related to growth, immunity, reproduction and behaviour were recorded under laboratory conditions. A total of 120 adults from wild or farm origin were first monitored during a 3-week stress period (high density and acute stress handling) during winter, followed by 6 months on-growing in sea-cages. Relationships between parameters were analyzed using a multi-factorial approach. Wild and farm stocks could only be discriminated on behaviour traits, confirming that the French abalone industry is in the beginning of the domestication process. After 3 weeks of chronic stress, the righting latency of an abalone was linked to better survival and faster growth. Abalones having the best growth after 6 months were characterized by higher activity during the previous winter period, whereas an early gonad maturation reduced the growth in summer. Our results provide a basis for the establishment of a multi-trait breeding program to improve the growth rate while controlling the evolution of physiological and behavioural traits. Statement of relevance The relationships of behavioural and physiological variables with survival and weight gain after application of important stressors were studied in order to provide a better understanding of Haliotis tuberculata biology during early domestication stage. This paper will give information on new targets and tools for selective breeding.

Farming, and thus the domestication of Haliotis tuberculata, began recently. We compared the responses of unselected farmed and wild abalone to stressors that occur on farms. The aim was to determine if the farm environment had induced differences in the behavioural or physiological performances of the abalone. Thirty hatchery-born 3.5 year-old abalone and thirty wild ones were reared under standard farm conditions for 6 months and characterised for 19 traits related to growth, survival, behaviour and immunology. Behavioural and immunological responses to stressors differed between the two stocks. Farmed abalone retracted and swivelled less in reaction to a finger contact. Phagocytosis efficiency was reduced by shaking in abalone from both origins, but the farmed stock returned to the basal level after the recovery week, while wild abalone did not, and a rise of total haemocyte count after shaking and its return to a basal level after one week was only observed for the farmed stock. This indicates that both behaviour and immune responses following a stress have been affected by the farming practices. This suggests that a domestication process has already been initiated in the farmed stock. Our results may also be important for the success of any population enhancement based on hatchery-produced abalone as they raise the question of the capacity of abalone with a farmed origin to be adapted to the wild environment.

Abalone growth rate is often identified among important traits to improve through selective breeding. However, the rapid success of some selective breeding plans has sometimes led to negative effects in some aquaculture species due to trade-offs. One of them is the loss of homeostasis of selected animals which results in the inability to resist the stress experienced during the rearing process. In this context, this study aimed to analyze the phenotypic relationships between growth, and physiological and behavioural traits in Haliotis tuberculata under stressful conditions. Eleven traits related to growth, immunity, reproduction and behaviour were recorded under laboratory conditions. A total of 120 adults from wild or farm origin were first monitored during a 3-week stress period (high density and acute stress handling) during winter, followed by 6 months on-growing in sea-cages. Relationships between parameters were analyzed using a multi-factorial approach. Wild and farm stocks could only be discriminated on behaviour traits, confirming that the French abalone industry is in the beginning of the domestication process. After 3 weeks of chronic stress, the righting latency of an abalone was linked to better survival and faster growth. Abalones having the best growth after 6 months were characterized by higher activity during the previous winter period, whereas an early gonad maturation reduced the growth in summer. Our results provide a basis for the establishment of a multi-trait breeding program to improve the growth rate while controlling the evolution of physiological and behavioural traits. Statement of relevance The relationships of behavioural and physiological variables with survival and weight gain after application of important stressors were studied in order to provide a better understanding of Haliotis tuberculata biology during early domestication stage. This paper will give information on new targets and tools for selective breeding.