The behavioural repertoire of Arctic charr (Salvelinus alpinus(L.)) in captivity: a case study for testing ethogram completeness and reducing observer effects

The ability to re-identify individuals is fundamental to the individual-based studies that are required to estimate many important ecological and evolutionary parameters in wild populations. Traditional methods of marking individuals and tracking them through time can be invasive and imperfect, which can affect these estimates and create uncertainties for population management. Here we present a photographic re-identification method that uses spot constellations in images to match specimens through time. Photographs of Arctic charr ( Salvelinus alpinus ) were used as a case study. Classical computer vision techniques were compared with new deep-learning techniques for masks and spot extraction. We found that a U-Net approach trained on a small set of human-annotated photographs performed substantially better than a baseline feature engineering approach. For matching the spot constellations, two algorithms were adapted, and, depending on whether a fully or semi-automated set-up is preferred, we show how either one or a combination of these algorithms can be implemented. Within our case study, our pipeline both successfully identified unmarked individuals from photographs alone and re-identified individuals that had lost tags, resulting in an approximately 4% increase in our estimate of survival rate. Overall, our multi-step pipeline involves little human supervision and could be applied to many organisms.

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Impaired Swimming Performance of Acid-exposed Arctic Charr, Salvelinus Alpinus L.

Water Quality Research Journal ◽

10.2166/wqrj.1988.021 ◽

1988 ◽

Vol 23 (2) ◽

pp. 301-307 ◽

Cited By ~ 2

Author(s):

L.A. Hunter ◽

E. Scherer

Keyword(s):

Dose Response ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Swimming Performance ◽

Control Level ◽

Ventilation Rates

Abstract Arctic charr (Salvelinus alpinus L.) were exposed to five levels of acidity between pH 6 and pH 3.8. Swimming performance as determined by critical swimming speeds was 67.5 cm · sࢤ1 or 4.4 body lengths per second for untreated fish (pH 7.8). Performance declined sharply below pH 4.5; at pH 3.8 it was reduced by 35% after 7 days of exposure. Tailbeat frequencies and ventilation rates showed no dose-response effects. At swimming speeds between 20 and 50 cm · sࢤ1, ventilation rates at all levels of acidity were higher than at the control level.

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A seasonal comparison of trace metal concentrations in the tissues of Arctic charr (Salvelinus alpinus) in Northern Québec, Canada

Ecotoxicology ◽

10.1007/s10646-020-02248-7 ◽

2020 ◽

Vol 29 (9) ◽

pp. 1327-1346

Author(s):

Mackenzie Anne Clifford Martyniuk ◽

Patrice Couture ◽

Lilian Tran ◽

Laurie Beaupré ◽

Nastassia Urien ◽

...

Keyword(s):

Trace Metal ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Metal Concentrations

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Genotyping Strategies Using ddRAD Sequencing in Farmed Arctic Charr (Salvelinus alpinus)

Animals ◽

10.3390/ani11030899 ◽

2021 ◽

Vol 11 (3) ◽

pp. 899

Author(s):

Fotis Pappas ◽

Christos Palaiokostas

Keyword(s):

Genetic Diversity ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Cost Effective ◽

Limiting Factors ◽

Phenotypic Traits ◽

Production Volume ◽

High Coverage ◽

Genomic Relationships ◽

Low Coverage

Incorporation of genomic technologies into fish breeding programs is a modern reality, promising substantial advances regarding the accuracy of selection, monitoring the genetic diversity and pedigree record verification. Single nucleotide polymorphism (SNP) arrays are the most commonly used genomic tool, but the investments required make them unsustainable for emerging species, such as Arctic charr (Salvelinus alpinus), where production volume is low. The requirement to genotype a large number of animals for breeding practices necessitates cost effective genotyping approaches. In the current study, we used double digest restriction site-associated DNA (ddRAD) sequencing of either high or low coverage to genotype Arctic charr from the Swedish national breeding program and performed analytical procedures to assess their utility in a range of tasks. SNPs were identified and used for deciphering the genetic structure of the studied population, estimating genomic relationships and implementing an association study for growth-related traits. Missing information and underestimation of heterozygosity in the low coverage set were limiting factors in genetic diversity and genomic relationship analyses, where high coverage performed notably better. On the other hand, the high coverage dataset proved to be valuable when it comes to identifying loci that are associated with phenotypic traits of interest. In general, both genotyping strategies offer sustainable alternatives to hybridization-based genotyping platforms and show potential for applications in aquaculture selective breeding.

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