Abstract
Background
The Atlantic mackerel, Scomber scombrus (Linnaeus, 1758) is a commercially valuable migratory pelagic fish inhabiting the northern Atlantic Ocean and the Mediterranean Sea. Given its highly migratory behaviour for feeding and spawning, several studies have been conducted to assess differentiation among spawning components to better define management units, as well as to investigate possible adaptations to comprehend and predict recent range expansion northwards.
Methods
Here, a high-quality genome of S. scombrus was sequenced and annotated, as an increasing number of population genetic studies have proven the relevance of reference genomes to investigate genomic markers/regions potentially linked to differences at finer scale. Such reference genome was used to map Restriction-site-associated sequencing (RAD-seq) reads for SNP discovery and genotyping in more than 500 samples distributed along the species range. The resulting genotyping tables have been used to perform connectivity and adaptation analyses.
Results
The assembly of the reference genome for S. scombrus resulted in a high-quality genome of 741 Mb. Our population genetic results show that the Atlantic mackerel consist of three previously known genetically isolated units (Northwest Atlantic, Northeast Atlantic, Mediterranean), and provide no evidence for genetically distinct spawning components within the Northwest or Northeast Atlantic.
Conclusions
Therefore, our findings resolved previous uncertainties by confirming the absence of genetically isolated spawning components in each side of the northern Atlantic, thus rejecting homing behaviour and the need to redefine management boundaries in this species. In addition, no further genetic signs of ongoing adaptation were detected in this species.
Plain language summary
The Atlantic mackerel is a commercially valuable migratory pelagic fish inhabiting the northern Atlantic Ocean and the Mediterranean Sea. In both sides of the Atlantic, this species spawns at several locations (spawning components) while migrating north for feeding. It has been hypothesized that the mackerel has a homing behaviour, meaning that they return to spawn to where they were born, in which case, genetic differences should be visible between spawning components. Here, we have sequenced the complete genome of Atlantic mackerel and performed population genetic analyses based on thousands of markers. Our results provide no evidence for genetically distinct spawning components which implies that, for fisheries management, this species should be managed as one unit in each side of the Atlantic.
The Atlantic mackerel, Scomber scombrus (Linnaeus, 1758) is a commercially valuable migratory pelagic fish inhabiting the northern Atlantic Ocean and the Mediterranean Sea. Given its highly migratory behaviour for feeding and spawning, several studies have been conducted to assess differentiation among spawning components to better define management units, as well as to investigate possible adaptations to comprehend and predict recent range expansion northwards.
Methods
Here, a high-quality genome of S. scombrus was sequenced and annotated, as an increasing number of population genetic studies have proven the relevance of reference genomes to investigate genomic markers/regions potentially linked to differences at finer scale. Such reference genome was used to map Restriction-site-associated sequencing (RAD-seq) reads for SNP discovery and genotyping in more than 500 samples distributed along the species range. The resulting genotyping tables have been used to perform connectivity and adaptation analyses.
Results
The assembly of the reference genome for S. scombrus resulted in a high-quality genome of 741 Mb. Our population genetic results show that the Atlantic mackerel consist of three previously known genetically isolated units (Northwest Atlantic, Northeast Atlantic, Mediterranean), and provide no evidence for genetically distinct spawning components within the Northwest or Northeast Atlantic.
Conclusions
Therefore, our findings resolved previous uncertainties by confirming the absence of genetically isolated spawning components in each side of the northern Atlantic, thus rejecting homing behaviour and the need to redefine management boundaries in this species. In addition, no further genetic signs of ongoing adaptation were detected in this species.
Plain language summary
The Atlantic mackerel is a commercially valuable migratory pelagic fish inhabiting the northern Atlantic Ocean and the Mediterranean Sea. In both sides of the Atlantic, this species spawns at several locations (spawning components) while migrating north for feeding. It has been hypothesized that the mackerel has a homing behaviour, meaning that they return to spawn to where they were born, in which case, genetic differences should be visible between spawning components. Here, we have sequenced the complete genome of Atlantic mackerel and performed population genetic analyses based on thousands of markers. Our results provide no evidence for genetically distinct spawning components which implies that, for fisheries management, this species should be managed as one unit in each side of the Atlantic.
| Original language | English |
|---|---|
| Article number | 82 |
| Journal | Open Research Europe |
| Volume | 4 |
| Number of pages | 21 |
| ISSN | 2732-5121 |
| DOIs | |
| Publication status | Published - 2024 |
Keywords
- Atlantic mackerel
- Complete genome
- RAD-seq
- Population structure
- Genome-wide SNPs
- Fisheries management
