Biology subjects

Wellenreuther, M.

Publications and source records attributed to Wellenreuther, M..

At least 19 recordsLinked to original sources

bioRxiv2025

Hybridization outcomes reflect context-dependent reproductive isolation in two damselfly hybrid zones

Pair of species with multiple hybrid zones provide powerful systems to examine how reproductive isolation and reinforcement may depend on ecological and demographic contexts. We conducted a comparative analysis of two hybrid zones between Ischnura elegans and Ischnura graellsii in North-central (NC) and North-western (NW) Spain to evaluate how differences in reproductive barriers shape patterns of hybridization and admixture. First, we quantified five prezygotic barriers in the NC hybrid zone--where no barrier estimates previously existed--and compared them with published data from the NW hybrid zone. Second, we conducted genomic analyses using 5,702 SNPs to assess genetic structure, differentiation, and diversity between species; and 381 SNPs with species-specific alleles to characterize hybrid classes and introgression across both regions. Reproductive isolation was strongly context dependent. Mechanical reinforcement acted in the same cross direction in both hybrid zones, but the NC hybrid zone also showed stronger gametic (fertility) isolation. Consequently, total prezygotic isolation was higher in the NC hybrid zone. These differences were also observed genomically: the NC hybrid zone exhibited limited and largely unidirectional introgression, whereas the NW hybrid zone showed more extensive admixture, bidirectional gene flow, and reduced interspecific differentiation, consistent with a longer or more sustained history of hybridization. Our results demonstrate that hybridization outcomes can differ markedly between hybrid zones involving the same pair of species, underscoring the importance of evaluating spatial variation in reproductive barriers and introgression to assess the presence, asymmetry, and repeatability of reinforcement, as well as the microevolutionary processes shaping hybrid zone structure.

evolutionary biology↗

bioRxiv2025

Biofouling on aquaculture mesh: disentangling seasonal and environmental effects with eDNA

Biofouling presents ecological and economic challenges for marine industries, yet patterns of community development in relevant environments remain underexplored. In this study, we examined seasonal (winter vs summer) and spatial (sheltered vs exposed) patterns in eukaryotic biofouling across six coastal sites in New Zealand. Using standardised mesh substrates and environmental DNA (eDNA) metabarcoding with the 18S rRNA gene, we characterised over 10,000 Amplicon Sequence Variants (ASVs) across 216 samples, revealing 541 species from 249 taxonomic classes. Exposed sites exhibited marked seasonal contrasts: winter communities were dominated by hydroids (e.g., Coryne eximia), while summer samples shifted to amphipod-rich assemblages (e.g., Jassa slatteryi). Sheltered sites showed more stable biomass and diversity but greater site-level variability, especially in summer. Temperature and wind fetch emerged as key environmental drivers, with larger seasonal fluctuations observed under high-exposure conditions. Notably, several dominant species were non-native, underscoring the importance of early detection. These findings highlight the value of molecular monitoring for predicting biofouling risks and informing site-specific antifouling strategies in dynamic marine environments.

ecology↗

bioRxiv2025

Environmental gradients decouple demographic and adaptive connectivity in a highly mobile coastal marine species

Understanding how eco-evolutionary processes shape genetic variation and persistence in marine species with highly variable recruitment dynamics and dispersal potential remains a fundamental challenge, particularly when considering the interplay between gene flow and local adaptation. Here, we employed a seascape genomics approach to investigate population connectivity and local adaptation in Australasian snapper (Chrysophrys auratus, Sparidae) along 1500 km of the environmentally heterogeneous southern Australian coastline. Using 14,699 SNPs, we identified two distinct regional populations aligned with known biogeographical regions. Genotype-environment association analyses revealed 855 candidate adaptive loci associated with environmental variation, including temperature, salinity, and primary productivity. Connectivity analyses using neutral markers indicated high gene flow throughout both eastern and western regions, while candidate adaptive loci revealed substantially reduced connectivity, especially for Northern Spencer Gulf and West Coast populations. This pattern of locally restricted gene flow at adaptive genomic regions suggests that strong environmental gradients are driving adaptive divergence despite high overall connectivity. Our results support contingent migration as a potential mechanism modulating the balance between local adaptation and gene flow in this economically and ecologically important marine species. These findings might also have implications for regional management of other coastal fisheries that are experiencing substantial declines. As climate change alters coastal marine environments around the world, the dynamics of local recruitment, site fidelity and local adaptation are expected to change. This highlights the importance of integrating knowledge about eco-evolutionary processes into marine resource management, fisheries stock assessment, and restocking and stock enhancement activities.

ecology↗

bioRxiv2025

Selective breeding and production strategies to support snapper farming in the warming waters of New Zealand's South Island

Diversifying aquaculture species is essential for building resilience in the face of climate change, particularly as warming oceans challenge existing production systems. In New Zealands Marlborough Sounds, rising sea temperatures are making salmon farming increasingly difficult, highlighting the need for climate-adapted alternatives. This study evaluated the aquaculture performance of selectively bred F4 versus unselected F1 Australasian snapper (Chrysophrys auratus) across two rearing environments: sea pens in the Marlborough Sounds and a land-based system in Nelson. Approximately 1,000 F4 and 1,000 F1 snapper were reared from 4 to 30 months of age in each system. At 30 months, selectively bred snapper showed improved growth-body length increased by 1.7% (land-based) and 4.8% (ocean-based), and body weight by 9.8% and 14.2%, respectively compared with F1 snapper. Survival was also significantly higher, with selected snapper outperforming controls by 84.2% in the land-based and 60.8% in the ocean-based system. Mortality peaked in the first winter across both systems, with size-selective patterns in sea pens informing minimum stocking sizes. These findings offer important insights for refining husbandry and selective breeding practices. They are not only relevant for New Zealand but also for global aquaculture sectors seeking robust species suited to changing marine environments.

zoology↗

bioRxiv2025

Integrating genomics, machine learning, and computer vision to understand growth traits in selectively bred snapper (Chrysophrys auratus)

Genomic prediction of complex traits is limited when phenotype records are restricted and when using linear models. Increasing the amount of phenotypic data with high-throughput, image-based phenotyping could result in better genomic prediction and stronger signals in variant detection. Here, we analysed phenotypic and genomic data from a selectively bred cohort of the Australasian snapper (Chrysophrys auratus) to identify genetic variants associated with growth traits. We used a high-throughput phenotyping pipeline to extract 13 measurements of size from images. Phenotypic correlations among image-derived and manually measured traits (weight, fork length), together with heritabilities, were analysed. All measurements were significantly positively correlated with each other, and heritability ranged from 0.20-0.38. Genome-wide association studies (GWAS) identified 28 growth-associated SNPs, while GBLUP was used to predict phenotypes, and XGBoost machine-learning models were used to jointly predict phenotypes and report important variants. Both GBLUP (mean R2 = 0.50) and XGBoost (mean R2 = 0.77) performed well on the training data, but performance dropped on testing sets (both = 0.11), which decreased further when accounting for genetic relatedness (both = 0.06). Despite this, approximately 20% of the genetic variance for growth traits was captured by the models, and feature importance from XGBoost reflected signals seen in GWAS. Our findings highlight the utility of integrating computer vision-based phenotyping with GWAS, GBLUP, and ML for trait prediction. Despite detecting shared biological signals as GWAS, genomic prediction faces challenges with population structure and relatedness that are inherent in breeding programmes of mass spawning species, including many aquatic species. Article summaryIncorporating genetic information into selective breeding programmes can accelerate gains but may also miss gene interactions in complex traits. Machine learning approaches, such as decision trees, can capture those relationships and potentially improve genomic predictions. We used high-throughput computer vision phenotyping to uncover biological signal for genetic growth variants involved in the Australasian snapper. Both types of models captured 18-40% of the genetic variation, but the prediction accuracies were hampered by the population structure in this cohort of mass-spawning fish.

genomics↗

bioRxiv2023

Estimation of effective population size and effective number of breeders in an abundant and heavily exploited marine teleost

Obtaining reliable estimates of the effective number of breeders N(b) and generational effective population size (Ne) for fishery-important species is challenging because they are often iteroparous and highly abundant, which can lead to bias and imprecision. However, recent advances in understanding of these parameters, as well as the development of bias correction methods, have improved the capacity to generate reliable estimates. We utilized samples of both single-cohort young of the year and mixed-age adults from two geographically and genetically isolated stocks of the Australasian snapper (Chrysophrys auratus) to investigate the feasibility of generating reliable Nb and Ne estimates for a fishery species. Snapper is an abundant, iteroparous broadcast spawning teleost that is heavily exploited by recreational and commercial fisheries. Employing neutral genome-wide SNPs and the linkage-disequilibrium method, we determined that the most reliable Nb and Ne estimates could be derived by genotyping at least 200 individuals from a single cohort. Although our estimates made from the mixed-age adult samples were generally lower and less precise than those based on a single cohort, they still proved useful for understanding relative differences in genetic effective size between stocks. The correction formulas applied to adjust for biases due to physical linkage of loci and age structure resulted in substantial upwards modifications of our estimates, demonstrating the importance of applying these bias corrections. Our findings provide important guidelines for estimatingNb and Ne for iteroparous species with large populations. This work also highlights the utility of samples originally collected for stock structure and stock assessment work for investigating genetic effective size in fishery-important species.

genomics↗

bioRxiv2023

Testing the predictions of reinforcement: long-term empirical data from a damselfly mosaic hybrid zone

Theoretical work suggests that reinforcement can cause the strengthening of prezygotic isolation in sympatry by mitigating the costs of maladaptive hybridization. However, only a handful of studies have tested all predictions of this theory in natural populations. We investigated reinforcement in a mosaic hybrid zone of the damselflies Ischnura elegans and I. graellsii. Firstly, we tested if the conditions of reinforcement were fulfilled by quantifying whether hybridization was costly, and prezygotic isolation was strengthening in sympatry compared with in allopatry. Secondly, we investigated three specific predictions of reinforcement: rarer female effect, presence of concordant prezygotic and postzygotic isolation asymmetries in sympatry, and greater premating asymmetries associated with weaker postzygotic isolation in sympatry. We found that reinforcement has strengthened mechanical isolation in one cross direction between species in sympatry. Our study details a case of reinforcement and heterospecific gene flow causing opposite effects between reciprocal heterospecific crosses and describes a natural model in which reproductive isolation is built by the simultaneous effects of reinforcement, the lock-and-key model, Bateson-Dobzhansky-Muller incompatibilities and Haldanes rule.

evolutionary biology↗

bioRxiv2023

Bioregional boundaries and genomically-delineated stocks in snapper (Chrysophrys auratus) from southeastern Australia

Marine species often exhibit genetic discontinuities concordant with biogeographic boundaries, frequently occurring due to changes in ocean circulation, bathymetry, coastline topography and temperature. Here we used 10,916 single nucleotide polymorphisms (SNPs) to assess the concordance between population genomic differentiation and coastal biogeography in the fishery important snapper (Chrysophrys auratus) across southeastern Australia. Additionally, we investigated whether spatial scales of assessment and management of snapper align with evidence from population genomics. Across 488 snapper samples from 11 localities between the west coast of South Australia and the south coast of New South Wales, we detected genomic structure concordant with the regions three biogeographic provinces. We also detected fine-scale genetic structuring relating to spatial variation in spawning and recruitment dynamics, as well as temporal stability in the genomic signal associated with two important spawning grounds. The current management boundaries in the region coincided with either the genetic breaks at bioregional boundaries or with localscale variation. Our study highlights the value of population genomic surveys in species with high dispersal potential for uncovering stock boundaries and demographic variation related to spawning and recruitment. It also illustrates the importance of marine biogeography in shaping population structure in commercial species with high dispersal potential.

genomics↗

bioRxiv2022

A multiplexed plant-animal SNP array for selective breeding and species conservation applications

Reliable and high-throughput genotyping platforms are of immense importance for identifying and dissecting genomic regions controlling important phenotypes, supporting selection processes in breeding programmes, and managing wild populations and germplasm collections. Amongst available genotyping tools, SNP arrays have been shown to be comparatively easy to use and generate highly accurate genotypic data. Single species arrays are the most commonly used type so far; however, some multi-species arrays have been developed for closely related species that share SNP markers, exploiting inter-species cross-amplification. In this study, the suitability of a multiplexed plant-animal SNP array, including both closely and distantly related species, was explored. The performance of the SNP array across species for diverse applications, ranging from intra-species diversity assessments to parentage analysis, was assessed. Moreover, the value of genotyping pooled DNA of distantly related species on the SNP array as a technique to further reduce costs was evaluated. SNP performance was generally high, and species-specific SNPs proved suitable for diverse applications. The multi-species SNP-array approach reported here could be transferred to other species to achieve cost savings resulting from the increased throughput when several projects use the same array, and the pooling technique adds another highly promising advancement to additionally decrease genotyping costs by half.

genetics↗

bioRxiv2022

Comparative genomics of tarakihi (Nemadactylus macropterus) and five New Zealand fish species: assembly contiguity affects the identification of genic features but not transposable elements

Comparative analysis of whole-genome sequences can provide valuable insights into the evolutionary patterns of diversification and adaptation of species, including the genome contents and the regions under selection. However, such studies are lacking for fishes in New Zealand. To supplement the recently sequenced genome of tarakihi (Nemadactylus macropterus), the genomes of five additional percomorph species native to New Zealand (king tarakihi (Nemadactylus n.sp.), blue moki (Latridopsis ciliaris), butterfish (Odax pullus), barracouta (Thyrsites atun), and kahawai (Arripis trutta)) were determined and assembled using Illumina sequencing. While the proportion of repeat elements was highly correlated with the genome size (R2 = 0.97, P < 0.01), most of the metrics for the genic features (e.g. number of exons or intron length) were significantly correlated with assembly contiguity (| R2| = 0.79-0.97). A phylogenomic tree including eight additional high-quality fish genomes was reconstructed from sequences of shared gene families. The radiation of Percomorpha was estimated to have occurred c. 112 mya (mid-Cretaceous), while the Latridae have diverged from true Perciformes c. 83 mya (late Cretaceous). Evidence of positive selection was found in 65 genes in tarakihi and 209 genes in Latridae: the largest portion of these are involved in the ATP binding pathway and the integral structure of membranes. These results and the de novo genome sequences can be used to (1) inform future studies on both the strength and shortcomings of scaffold-level assemblies for comparative genomics and (2) provide insights into the evolutionary patterns and processes of genome evolution in bony fishes.

genomics↗

bioRxiv2022

Fish as model systems to study epigenetic drivers in human self-domestication and neurodevelopmental cognitive disorders

Modern humans exhibit phenotypic traits that are shared across independent domestication events, suggesting the human self-domestication hypothesis. Epigenetic changes may facilitate early self-domestication in humans, since they can be the first layer of response to a novel environment. Here, we argue that fish provide model systems to study epigenetic drivers in human self-domestication. To do this, we compare genes that carry epigenetic changes in early domesticates of European sea bass with 1) anatomically modern humans and 2) neurodevelopmental cognitive disorders with abnormal self-domestication traits, i.e., schizophrenia, Williams syndrome and autism spectrum disorders. We found that genes with epigenetic changes in fish and in modern vs ancient humans were shared and were involved in processes like limb morphogenesis and phenotypes like abnormal snout morphology and hypopigmentation. Moreover, early domestication in fish and neurodevelopmental cognitive impairment in humans affected paralogue genes involved in processes such as neural crest differentiation and ectoderm differentiation. We conclude that parallel epigenetic changes may occur at the initial steps of domestication in absence of deliberate selection in phylogenetically distant vertebrates. These findings pave the way for future studies using fish as models to investigate epigenetic changes as drivers of human-self domestication and as triggers of cognitive disorders.

evolutionary biology↗

bioRxiv2022

Genome assembly and isoform analysis of a highly heterozygous New Zealand fisheries species, the tarakihi (Nemadactylus macropterus)

Although being some of the most valuable and heavily exploited wild organisms, few fisheries species have been studied at the whole-genome level. This is especially the case in New Zealand, where genomics resources are urgently needed to assist fisheries management attains its sustainability goals. Here we generated 55 Gb of short Illumina reads (92x coverage) and 73 Gb of long Nanopore reads (122x) to produce the first genome assembly of the marine teleost tarakihi (Nemadactylus macropterus), a highly valuable fisheries species in New Zealand. An additional 300 Mb of Iso-Seq RNA reads were obtained from four tissue types of another specimen to assist in gene annotation. The final genome assembly was 568 Mb long and consisted of 1,214 scaffolds with an N50 of 3.37 Mb. The genome completeness was high, with 97.8% of complete Actinopterygii BUSCOs. Heterozygosity values estimated through k-mer counting (1.00%) and bi-allelic SNPs (0.64%) were high compared to the same values reported for other fishes. Repetitive elements covered 30.45% of the genome and 20,169 protein-coding genes were annotated. Iso-Seq analysis recovered 91,313 unique transcripts (isoforms) from 15,515 genes (mean ratio of 5.89 transcripts per gene), and the most common alternative splicing event was intron retention. This highly contiguous genome assembly along with the isoform-resolved transcriptome will provide a useful resource to assist the study of population genomics, as well as comparative eco-evolutionary studies in other teleost and related organisms.

genomics↗

bioRxiv2022

Fisheries genomics of snapper (Chrysophrys auratus) along the western Australian coast

The efficacy of fisheries management strategies depends on stock assessment and management actions being carried out at appropriate spatial scales. This requires understanding of spatial and temporal population structure and connectivity, which is challenging in weakly structured and highly connected marine populations. We carried out a population genomics study of the heavily exploited snapper (Chrysophrys auratus) along [~]2,600 km of the Australian coastline, with a focus on Western Australia (WA). We used 10,903 filtered SNPs in 341 individuals from eight locations to characterise population structure and connectivity in snapper across WA and to assess if current spatial scales of stock assessment and management agree with evidence from population genomics. Our dataset also enabled us to investigate temporal stability in population structure as well as connectivity between WA and its nearest, eastern jurisdictional neighbor. As expected for a species influenced by the extensive ocean boundary current in the region, low genetic differentiation and high connectivity was uncovered across WA. However, we did detect strong isolation by distance and genetic discontinuities in the mid-west and south-east. The discontinuities correlate with boundaries between biogeographic regions, influenced by on-shelf oceanography, and the sites of important spawning aggregations. We also detected temporal instability in genetic structure at one of our sites, possibly due to interannual variability in recruitment in adjacent regions. Our results partly contrast with the current spatial management of snapper in WA, highlighting the need for a review. This study supports the value of population genomic surveys in informing the management of weakly-structured and wide-ranging marine fishery resources.

genomics↗

bioRxiv2022

Genomic stock structure of the marine teleost tarakihi (Nemadactylus macropterus) provides evidence of fine-scale adaptation and a temperature-associated cline amid panmixia

Tarakihi (Nemadactylus macropterus) is an important fishery species with widespread distribution around New Zealand and off the southern coasts of Australia. However, little is known about whether the populations are locally adapted or genetically structured. To address this, we conducted whole-genome resequencing of 175 tarakihi from around New Zealand and Tasmania (Australia) to obtain a dataset of 7.5 million genome-wide and high-quality single nucleotide polymorphisms (SNPs). Variant filtering, FST-outlier analysis, and redundancy analysis (RDA) were used to evaluate population structure, adaptive structure, and locus-environment associations. A weak but significant level of neutral genetic differentiation was found between tarakihi from New Zealand and Tasmania (FST = 0.0054-0.0073, P [≤] 0.05), supporting the existence of at least two separate reproductive stocks. No clustering was detected among the New Zealand populations ([FE]ST < 0.001, P = 0.77). Outlier-based, presumably adaptive variation suggests fine-scale adaptive structure between locations around central New Zealand off the east (Wairarapa, Cape Campbell, and Hawkes Bay) and the west coast (Tasman Bay/Golden Bay and Upper West Coast of South Island). Allele frequencies from 55 loci were associated with at least one of six environmental variables, of which 47 correlated strongly with yearly mean water temperature. Although genes associated with these loci are linked to various functions, the most common functions were integral components of membrane and cilium assembly. Projection of the RDA indicates the existence of a latitudinal temperature cline. Our work provides the first genomic insights supporting panmixia of tarakihi in New Zealand and evidence of a genomic cline that appears to be driven by the temperature gradients, together providing crucial information to inform the stock assessment of this species, and to widen the insights of the ecological drivers of adaptive variation in a marine species.

genomics↗

bioRxiv2021

Restricted X chromosome introgression and support for Haldane's rule in hybridizing damselflies

Contemporary hybrid zones act as natural laboratories for the investigation of species boundaries and allow to shed light on the little understood roles of sex chromosomes in species divergence. Sex chromosomes are considered to function as a hotspot of genetic divergence between species; indicated by less genomic introgression compared to autosomes during hybridisation. Moreover, they are thought to contribute to Haldanes rule which states that hybrids of the heterogametic sex are more likely to be inviable or sterile. To test these hypotheses, we used contemporary hybrid zones of Ischnura elegans, a damselfly species that has been expanding its range into the northern and western regions of Spain, leading to chronic hybridization with its sister species Ischnura graellsii. We analysed genome-wide SNPs in the Spanish I. elegans and I. graellsii hybrid zone and found (i) that the X chromosome shows less genomic introgression compared to autosomes and (ii) that males are underrepresented among admixed individuals as predicted by Haldanes rule. This is the first study in Odonata that suggests a role of the X chromosome in reproductive isolation. Moreover, our data adds to the few studies on species with X0 sex determination system and contradicts the hypothesis that the absence of a Y chromosome causes exceptions to Haldanes rule.

evolutionary biology↗

bioRxiv2021

A metagenomic analysis of the wrackbed microbiome indicates a phylogeographic break along the North Sea - Baltic Sea transition zone

Sandy beaches are biogeochemical hotspots that bridge marine and terrestrial ecosystems via the transfer of marine organic matter, such as seaweed (termed wrack). A keystone of this unique ecosystem is the microbial community, which helps to degrade wrack and re-mineralize nutrients. However, little is known about the wrackbed microbiome, its composition, trophic ecology, or how it varies over time and space. Here we characterize the wrackbed microbiome as well as the microbiome of a primary consumer, the seaweed fly Coelopa frigida, and examine how they change along one of the most studied ecological gradients in the world, the transition from the marine North Sea to the brackish Baltic Sea. We found that polysaccharide degraders dominated both the wrackbed and seaweed fly microbiomes but there were still consistent differences between wrackbed and fly samples. Furthermore, we observed a shift in both microbial communities and functionality between the North and Baltic Sea. These shifts were mostly due to changes in the frequency of different groups of known polysaccharide degraders (Proteobacteria and Bacteroidota). We hypothesize that microbes were selected for their abilities to degrade different polysaccharides corresponding to a shift in polysaccharide content in the seaweed communities of the North vs. Baltic Sea. Our results reveal the complexities of both the wracked microbial community, with different groups specialized to different roles, and the cascading trophic consequences of shifts in the near shore algal community.

genomics↗

bioRxiv2021

Unravelling the complex genetic basis of growth in New Zealand silver trevally (Pseudocaranx georgianus)

Growth directly influences production rate and therefore is one of the most important and well-studied trait in animal breeding. However, understanding the genetic basis of growth has been hindered by its typically complex polygenic architecture. Here, we performed quantitative trait locus (QTL) mapping and genome-wide association studies (GWAS) for 10 growth traits that were observed over two years in 1,100 F1 captive-bred trevally (Pseudocaranx georgianus). We constructed the first high-density linkage map for trevally, which included 19,861 single nucleotide polymorphism (SNP) markers, and discovered eight QTLs for height, length and weight on linkage groups 3, 14 and 18. Using GWAS, we further identified 113 SNP-trait associations, uncovering 10 genetic hot spots involved in growth. Two of the markers found in the GWAS co-located with the QTLs previously mentioned, demonstrating that combining QTL mapping and GWAS represents a powerful approach for the identification and validation of loci controlling complex traits. This is the first study of its kind for trevally. Our findings provide important insights into the genetic architecture of growth in this species and supply a basis for fine mapping QTLs, marker-assisted selection, and further detailed functional analysis of the genes underlying growth in trevally.

genomics↗

bioRxiv2021

Genomic prediction of growth in a commercially, recreationally, and culturally important marine resource, the Australian snapper (Chrysophrys auratus)

Growth is one of the most important traits of an organism. For exploited species, this trait has ecological and evolutionary consequences as well as economical and conservation significance. Rapid changes in growth rate associated with anthropogenic stressors have been reported for several marine fishes, but little is known about the genetic basis of growth traits in teleosts. We used reduced genome representation data and genome-wide association approaches to identify growth-related genetic variation in the commercially, recreationally, and culturally important Australian snapper (Chrysophrys auratus, Sparidae). Based on 17,490 high-quality SNPs and 363 individuals representing extreme growth phenotypes from 15,000 fish of the same age and reared under identical conditions in a sea pen, we identified 100 unique candidates that were annotated to 51 proteins. We documented a complex polygenic nature of growth in the species that included several loci with small effects and a few loci with larger effects. Overall heritability was high (75.7%), reflected in the high accuracy of the genomic prediction for the phenotype (small vs large). Although the SNPs were distributed across the genome, most candidates (60%) clustered on chromosome 16, which also explains the largest proportion of heritability (16.4%). This study demonstrates that reduced genome representation SNPs and the right bioinformatic tools provide a cost-efficient approach to identify growth-related loci and to describe genomic architectures of complex quantitative traits. Our results help to inform captive aquaculture breeding programmes and are of relevance to monitor growth-related evolutionary shifts in wild populations in response to anthropogenic pressures.

genomics↗