Fast and cost-efficient species identification of Atlantic salmon (Salmo salar L.), brown trout (Salmo trutta), and their hybrids using a single SNP marker.

A workflow for developing a cost- and time-efficient, single nucleotide polymorphism (SNP)-based assay for species and hybrid identification is described. In a reference set (n = 46), the developed assay identified individuals of two closely related species, the Atlantic salmon (Salmo salar L., n = 23) and brown trout (Salmo trutta, n = 23), with 100% accuracy.

The Effects of Hybridization and Parasite Infection on the Survival and Behaviour of Endangered Landlocked Salmon Subject to Predation-Implications for Genetic Rescue.

A prerequisite of genetic rescue in endangered and genetically depauperate populations is to pre-evaluate between possible pros and cons of hybridization for the life history and survival of the target population. We hybridized the critically endangered Saimaa landlocked salmon ( m. ) with one of its geographically closest relatives, anadromous Baltic salmon from River Kymijoki.

Selection among critically endangered landlocked salmon ( m. ) families in survival and growth traits across early life stages and in different environments.

Endangered wild fish populations are commonly supported by hatchery propagation. However, hatchery-reared fish experience very different selective pressures compared to their wild counterparts, potentially causing genotype-by-environment interactions (G × E) in essential fitness traits. We experimentally studied early selection in a critically endangered landlocked Atlantic salmon population, first from fertilization to the swim-up stage in a common hatchery setting, and thereafter until the age of 5 months in two contrasting rearing environments.

Exposure of gametes to aged nano-sized plastic particles during fertilization can influence early larval development in the European whitefish (Coregonus lavaretus).

Plastic pollution has been a growing environmental concern for decades, increasingly affecting both marine and freshwater ecosystems worldwide. Nano-sized plastic particles (NPs) potentially have various toxicological impacts on aquatic organisms and the ecosystem; however, less is known about their possible adverse effects on the reproductive biology and offspring traits of fishes. The present study investigated whether an acute exposure of gametes to aged NPs during fertilization affects offspring early mortality, hatching time, body size at hatching or swimming performance of larvae in a common freshwater fish, the European whitefish (Coregonus lavaretus).

The effects of environmental enrichment on hatchery-performance, smolt migration and capture rates in landlocked Atlantic salmon.

Enrichment of rearing environment with natural elements has been suggested to improve the welfare and post-release survival of cultured fish. We studied the combined effects of shelter structures, periodical water flow and water level changes on pre- and post-release performance of critically endangered landlocked Atlantic salmon (Salmo salar m. sebago).

Ultra-acute exposure to cadmium does not impair whitefish sperm motility.

Cadmium (Cd) exposure can impair the traits of aquatic animals associated with reproduction. In natural lakes Cd is typically detected at concentrations below 0.001 mg l .

Do whitefish (Coregonus lavaretus) larvae show adaptive variation in the avoidance of microplastic ingestion?

The presence of microplastics in aquatic ecosystems has recently received increased attention. Small plastic particles may resemble natural food items of larval fish and other aquatic organisms, and create strong selective pressures on the feeding traits in exposed populations. Here, we examined if larval ingestion of 90 μm polystyrene microspheres, in the presence of zooplankton (Artemia nauplii, mean length = 433 μm), shows adaptive variation in the European whitefish (Coregonus lavaretus).

Offspring phenotype is shaped by the nonsperm fraction of semen.

In a large majority of animal species, the only contribution of males to the next generation has been assumed to be their genes (sperm). However, along with sperm, seminal plasma contains a wide array of extracellular factors that have many important functions in reproduction. Yet, the potential intergenerational effects of these factors are virtually unknown.

Experimental crossbreeding reveals strain-specific variation in mortality, growth and personality in the brown trout (Salmo trutta).

Although hybridization between populations with low genetic diversity may induce heterosis, it can also lead to reduced fitness of hybrid offspring through outbreeding depression and loss of local adaptations. Using a half-sib mating design, we studied on brown trout (Salmo trutta) how hybridization of migratory hatchery-strain females with males from various strains would affect early mortality, growth and personality in F offspring. No differences in mortality or alevin body length were found between the crossing groups by the end of the yolk-sac stage.

Sperm pre-fertilization thermal environment shapes offspring phenotype and performance.

The sperm pre-fertilization environment has recently been suggested to mediate remarkable transgenerational consequences for offspring phenotype (transgenerational plasticity, TGB), but the adaptive significance of the process has remained unclear. Here, we studied the transgenerational effects of sperm pre-fertilization thermal environment in a cold-adapted salmonid, the European whitefish (). We used a full-factorial breeding design where the eggs of five females were fertilized with the milt of 10 males that had been pre-incubated at two different temperatures (3.

Thermal sensitivity of growth indicates heritable variation in 1-year-old rainbow trout (Oncorhynchus mykiss).

Background: Rainbow trout is an important aquaculture species, which has a worldwide distribution across various production environments. The diverse locations of trout farms involve remarkable variation in environmental factors such as water temperature, which is of major importance for the performance of fish. Thus, robust fish that could thrive under different and suboptimal thermal conditions is a desirable goal for trout breeding.

Genetic (co)variance of rainbow trout (Oncorhynchus mykiss) body weight and its uniformity across production environments.

Background: When rainbow trout from a single breeding program are introduced into various production environments, genotype-by-environment (GxE) interaction may occur. Although growth and its uniformity are two of the most important traits for trout producers worldwide, GxE interaction on uniformity of growth has not been studied. Our objectives were to quantify the genetic variance in body weight (BW) and its uniformity and the genetic correlation (rg) between these traits, and to investigate the degree of GxE interaction on uniformity of BW in breeding (BE) and production (PE) environments using double hierarchical generalized linear models.

Female ornaments revisited - are they correlated with offspring quality?

The evolution and signalling content of female ornamentation has remained an enduring challenge to evolutionary biologists, despite the fact that secondary sexual characters are widespread in females. While females usually invest significant amounts of their resources, including carotenoids, in offspring, all the resources allocated to elaborate ornamentation reduce resources available for other purposes. This may in turn constrain female fitness leading to dishonest female signalling.

Genetics of microenvironmental sensitivity of body weight in rainbow trout (Oncorhynchus mykiss) selected for improved growth.

Microenvironmental sensitivity of a genotype refers to the ability to buffer against non-specific environmental factors, and it can be quantified by the amount of residual variation in a trait expressed by the genotype's offspring within a (macro)environment. Due to the high degree of polymorphism in behavioral, growth and life-history traits, both farmed and wild salmonids are highly susceptible to microenvironmental variation, yet the heritable basis of this characteristic remains unknown. We estimated the genetic (co)variance of body weight and its residual variation in 2-year-old rainbow trout (Oncorhynchus mykiss) using a multigenerational data of 45,900 individuals from the Finnish national breeding programme.

Genetic and potential non-genetic benefits increase offspring fitness of polyandrous females in non-resource based mating system.

Background: The adaptive significance of female polyandry is currently under considerable debate. In non-resource based mating systems, indirect, i.e.