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Kennedy RJ, Barry J, Boyd A, Allen M. Does phenology influence predation rate on Salmo trutta parr during lake migration? JOURNAL OF FISH BIOLOGY 2024. [PMID: 38491848 DOI: 10.1111/jfb.15719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/18/2024]
Abstract
Acoustic tags fitted with predation sensors, which trigger following ingestion by piscivorous predators, were used to compare direct predation rates during downstream migration (out-migration) of potamodromous (freshwater) brown trout (Salmo trutta L.) parr from their natal river into a large freshwater lake system during spring and autumn. Thirty-eight spring migrants were tagged across two study years (2021 and 2022) of which 13 individuals (34%) were predated. By contrast 40 autumn migrants were tagged (2020 and 2021) of which three individuals (7.5%) experienced predation. The overall predation loss rate for spring migrants was 0.342% day-1 and was 0.075% day-1 for autumn migrants. Most predation events during spring (77%) occurred within the lower river before tagged fish entered the lake, whilst no predation events were recorded within the river in the autumn. Predation events were significantly linked to tagging season (spring or autumn), with the probability of tags remaining untriggered (as a proxy for survival) being higher 93% (95% confidence interval [CI] [87%, 100%]) in autumn than in spring 66% (95% CI [53%, 83%]). The spring migration periods showed significantly lower river discharge (0.321 m3 /s mean daily discharge, April 1 to May 31) to those measured during autumn (1.056 m3 /s mean daily discharge, October 1 to November 30) (Mann-Whitney U-test, U = 1149, p < 0.001). Lower flows, clearer water, and longer sojourn in the river may have contributed to greater predation losses in the spring relative to the autumn.
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Affiliation(s)
| | | | - Adele Boyd
- Agri-Food & Biosciences Institute, Belfast, Northern Ireland
| | - Michelle Allen
- Agri-Food & Biosciences Institute, Belfast, Northern Ireland
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2
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Jonsson B, Greenberg L. Egg incubation temperature influences the population-specific outmigration rate of juvenile brown trout Salmo trutta. JOURNAL OF FISH BIOLOGY 2022; 100:909-917. [PMID: 35195904 PMCID: PMC9311069 DOI: 10.1111/jfb.15022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/21/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
The present experiment tested if temperature during embryogenesis and parental heritage affected the migratory behaviour of young brown trout Salmo trutta. Two parental forms were used, a freshwater resident form and an anadromous form, both from the same river system but geographically isolated since 1993-95. Four groups of young S. trutta were produced and reared from (a) freshwater resident parents spawning in a tributary to the River Imsa, Norway, (b) anadromous parents spawning in the main stem of the same river system, (c) resident male × anadromous female parents and (d) resident female × anadromous male parents. The eggs were incubated until first exogenous feeding in River Imsa water, either unheated or heated c. 2.7°C above ambient temperature. Thereafter, all fish experienced the same ambient river temperature until release. Groups were released below an impassable waterfall 900 m upstream of the mouth of the River Imsa, either as age-0 in October 2019 or as age-1 in May 2020. About 7.5% of the released fish moved downstream and were captured in a trap at the outlet. For any given body size, the proportion of warm incubated trout that moved downstream was greater than the proportion of cold incubated trout. It was also found that most emigrants of the October-released S. trutta were caught within a month of release. Also, most May-released S. trutta emigrated in October. The offspring of the freshwater resident parents emigrated to a larger extent than offspring of anadromous parents. Thus, the difference in emigration with regard to embryonic temperature was phenotypically plastic and may be associated with an epigenetic effect of the thermal conditions during early development. The effect of parental origin suggests there may be genetic divergence between the geographically isolated populations.
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Affiliation(s)
- Bror Jonsson
- Norwegian Institute for Nature ResearchOsloNorway
| | - Larry Greenberg
- Department of Environmental and Life Sciences, River Ecology and Management Research GroupKarlstad UniversityKarlstadSweden
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3
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Crabot J, Mondy CP, Usseglio-Polatera P, Fritz KM, Wood PJ, Greenwood MJ, Bogan MT, Meyer EI, Datry T. A global perspective on the functional responses of stream communities to flow intermittence. ECOGRAPHY 2021; 44:1511-1523. [PMID: 34720401 PMCID: PMC8554635 DOI: 10.1111/ecog.05697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
The current erosion of biodiversity is a major concern that threatens the ecological integrity of ecosystems and the ecosystem services they provide. Due to global change, an increasing proportion of river networks are drying and changes from perennial to non-perennial flow regimes represent dramatic ecological shifts with potentially irreversible alterations of community and ecosystem dynamics. However, there is minimal understanding of how biological communities respond functionally to drying. Here, we highlight the taxonomic and functional responses of aquatic macroinvertebrate communities to flow intermittence across river networks from three continents, to test predictions from underlying trait-based conceptual theory. We found a significant breakpoint in the relationship between taxonomic and functional richness, indicating higher functional redundancy at sites with flow intermittence higher than 28%. Multiple strands of evidence, including patterns of alpha and beta diversity and functional group membership, indicated that functional redundancy did not compensate for biodiversity loss associated with increasing intermittence, contrary to received wisdom. A specific set of functional trait modalities, including small body size, short life span and high fecundity, were selected with increasing flow intermittence. These results demonstrate the functional responses of river communities to drying and suggest that on-going biodiversity reduction due to global change in drying river networks is threatening their functional integrity. These results indicate that such patterns might be common in these ecosystems, even where drying is considered a predictable disturbance. This highlights the need for the conservation of natural drying regimes of intermittent rivers to secure their ecological integrity.
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Affiliation(s)
| | | | | | - Ken M Fritz
- Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA
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4
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Archer LC, Hutton SA, Harman L, Russell Poole W, Gargan P, McGinnity P, Reed TE. Associations between metabolic traits and growth rate in brown trout ( Salmo trutta) depend on thermal regime. Proc Biol Sci 2021; 288:20211509. [PMID: 34521251 PMCID: PMC8441116 DOI: 10.1098/rspb.2021.1509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/17/2021] [Indexed: 02/04/2023] Open
Abstract
Metabolism defines the energetic cost of life, yet we still know relatively little about why intraspecific variation in metabolic rate arises and persists. Spatio-temporal variation in selection potentially maintains differences, but relationships between metabolic traits (standard metabolic rate (SMR), maximum metabolic rate (MMR), and aerobic scope) and fitness across contexts are unresolved. We show that associations between SMR, MMR, and growth rate (a key fitness-related trait) vary depending on the thermal regime (a potential selective agent) in offspring of wild-sampled brown trout from two populations reared for approximately 15 months in either a cool or warm (+1.8°C) regime. SMR was positively related to growth in the cool, but negatively related in the warm regime. The opposite patterns were found for MMR and growth associations (positive in warm, negative in the cool regime). Mean SMR, but not MMR, was lower in warm regimes within both populations (i.e. basal metabolic costs were reduced at higher temperatures), consistent with an adaptive acclimation response that optimizes growth. Metabolic phenotypes thus exhibited a thermally sensitive metabolic 'floor' and a less flexible metabolic 'ceiling'. Our findings suggest a role for growth-related fluctuating selection in shaping patterns of metabolic variation that is likely important in adapting to climate change.
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Affiliation(s)
- Louise C. Archer
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork, Ireland
| | - Stephen A. Hutton
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork, Ireland
| | - Luke Harman
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork, Ireland
| | | | - Patrick Gargan
- Inland Fisheries Ireland, 3044 Lake Drive, Citywest Business Campus, Dublin D24 Y265, Ireland
| | - Philip McGinnity
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
- Marine Institute, Furnace, Newport, Co. Mayo, Ireland
| | - Thomas E. Reed
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork, Ireland
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5
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Duval E, Skaala Ø, Quintela M, Dahle G, Delaval A, Wennevik V, Glover KA, Hansen MM. Long-term monitoring of a brown trout (Salmo trutta) population reveals kin-associated migration patterns and contributions by resident trout to the anadromous run. BMC Ecol Evol 2021; 21:143. [PMID: 34256705 PMCID: PMC8276402 DOI: 10.1186/s12862-021-01876-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND In species showing partial migration, as is the case for many salmonid fishes, it is important to assess how anthropogenic pressure experienced by migrating individuals affects the total population. We focused on brown trout (Salmo trutta) from the Guddal River in the Norwegian Hardanger Fjord system, which encompasses both resident and anadromous individuals. Aquaculture has led to increased anthropogenic pressure on brown trout during the marine phase in this region. Fish traps in the Guddal River allow for sampling all ascending anadromous spawners and descending smolts. We analyzed microsatellite DNA markers from all individuals ascending in 2006-2016, along with all emigrating smolts in 2017. We investigated (1) if there was evidence for declines in census numbers and effective population size during that period, (2) if there was association between kinship and migration timing in smolts and anadromous adults, and (3) to what extent resident trout were parents of outmigrating smolts. RESULTS Census counts of anadromous spawners showed no evidence for a decline from 2006 to 2016, but were lower than in 2000-2005. Estimates of effective population size also showed no trends of declines during the study period. Sibship reconstruction of the 2017 smolt run showed significant association between kinship and migration timing, and a similar association was indicated in anadromous spawners. Parentage assignment of 2017 smolts with ascending anadromous trout as candidate parents, and assuming that unknown parents represented resident trout, showed that 70% of smolts had at least one resident parent and 24% had two resident parents. CONCLUSIONS The results bear evidence of a population that after an initial decline has stabilized at a lower number of anadromous spawners. The significant association between kinship and migration timing in smolts suggests that specific episodes of elevated mortality in the sea could disproportionally affect some families and reduce overall effective population size. Finally, the results based on parentage assignment demonstrate a strong buffering effect of resident trout in case of elevated marine mortality affecting anadromous trout, but also highlight that increased mortality of anadromous trout, most of which are females, may lower overall production in the system.
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Affiliation(s)
- Eloïse Duval
- Department of Biology, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.
- Theoretical and Experimental Ecology Station, UMR-5321, CNRS, University of Toulouse III Paul Sabatier, 2 route du CNRS, 09200, Moulis, France.
| | - Øystein Skaala
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway.
| | - María Quintela
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
| | - Geir Dahle
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
| | - Aurélien Delaval
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Vidar Wennevik
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
| | - Kevin A Glover
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
- Institute of Biology, University of Bergen, Bergen, Norway
| | - Michael M Hansen
- Department of Biology, Aarhus University, Ny Munkegade 114, 8000, Aarhus C, Denmark.
- Department of Aquaculture, Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway.
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Desforges JE, Birnie-Gauvin K, Aarestrup K, Cooke SJ. Upper Thermal Tolerance Indicated by CT max Fails to Predict Migration Strategy and Timing, Growth, and Predation Vulnerability in Juvenile Brown Trout ( Salmo trutta). Physiol Biochem Zool 2021; 94:215-227. [PMID: 33974516 DOI: 10.1086/714636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractPartial migration is common in a variety of taxa and has important ecological and evolutionary implications, yet the underlying factors that lead to different migratory strategies are not clearly understood. Given the importance of temperature in serving as a cue for migration, along with its role in regulating metabolism, growth, reproduction, and survival, we examined how intraspecific variation in critical thermal maximum (CTmax) values influenced migratory strategy (residency vs. migration), timing of migration, growth, and predation vulnerability in a wild population of partially anadromous juvenile brown trout (Salmo trutta). Using passive integrated transponder telemetry and mark-recapture techniques, we identified individuals that out-migrated to sea, assumed residency, and were predated by cormorants several months later. Acute thermal stress induced by conducting CTmax trials did not affect the final fate of assayed fish compared with controls. We found that mass and body condition predicted CTmax and migration timing, but CTmax failed to predict migratory strategy or timing, growth (of resident fish), or predation vulnerability. Although there may be links between mass, thermal tolerance, and migration strategy, the relationship between CTmax and migration remains unclear. The role of upper thermal tolerance in influencing life-history strategies should not be neglected, however, as alternative indicators of thermal tolerance could be further explored. The high degree of variation in CTmax estimates warrants additional investigation of how increasingly prevalent high-temperature events might drive selection toward thermally tolerant extremes, which is particularly relevant in a rapidly warming world.
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Wynne R, Archer LC, Hutton SA, Harman L, Gargan P, Moran PA, Dillane E, Coughlan J, Cross TF, McGinnity P, Colgan TJ, Reed TE. Alternative migratory tactics in brown trout ( Salmo trutta) are underpinned by divergent regulation of metabolic but not neurological genes. Ecol Evol 2021; 11:8347-8362. [PMID: 34188891 PMCID: PMC8216917 DOI: 10.1002/ece3.7664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/15/2021] [Accepted: 04/18/2021] [Indexed: 12/03/2022] Open
Abstract
The occurrence of alternative morphs within populations is common, but the underlying molecular mechanisms remain poorly understood. Many animals, for example, exhibit facultative migration, where two or more alternative migratory tactics (AMTs) coexist within populations. In certain salmonid species, some individuals remain in natal rivers all their lives, while others (in particular, females) migrate to sea for a period of marine growth. Here, we performed transcriptional profiling ("RNA-seq") of the brain and liver of male and female brown trout to understand the genes and processes that differentiate between migratory and residency morphs (AMT-associated genes) and how they may differ in expression between the sexes. We found tissue-specific differences with a greater number of genes expressed differentially in the liver (n = 867 genes) compared with the brain (n = 10) between the morphs. Genes with increased expression in resident livers were enriched for Gene Ontology terms associated with metabolic processes, highlighting key molecular-genetic pathways underlying the energetic requirements associated with divergent migratory tactics. In contrast, smolt-biased genes were enriched for biological processes such as response to cytokines, suggestive of possible immune function differences between smolts and residents. Finally, we identified evidence of sex-biased gene expression for AMT-associated genes in the liver (n = 12) but not the brain. Collectively, our results provide insights into tissue-specific gene expression underlying the production of alternative life histories within and between the sexes, and point toward a key role for metabolic processes in the liver in mediating divergent physiological trajectories of migrants versus residents.
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Affiliation(s)
- Robert Wynne
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Louise C. Archer
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Stephen A. Hutton
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Luke Harman
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | | | - Peter A. Moran
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
- Present address:
Department of Ecological Science – Animal EcologyVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Eileen Dillane
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Jamie Coughlan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Thomas F. Cross
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Philip McGinnity
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
- Marine InstituteNewportIreland
| | - Thomas J. Colgan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
- Present address:
Institute of Organismic and Molecular EvolutionJohannes Gutenberg University MainzMainzGermany
| | - Thomas E. Reed
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
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8
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Birnie-Gauvin K, Bordeleau X, Cooke SJ, Davidsen JG, Eldøy SH, Eliason EJ, Moore A, Aarestrup K. Life-history strategies in salmonids: the role of physiology and its consequences. Biol Rev Camb Philos Soc 2021; 96:2304-2320. [PMID: 34043292 DOI: 10.1111/brv.12753] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 01/02/2023]
Abstract
Salmonids are some of the most widely studied species of fish worldwide. They span freshwater rivers and lakes to fjords and oceans; they include short- and long-distance anadromous migrants, as well as partially migratory and non-migratory populations; and exhibit both semelparous and iteroparous reproduction. Salmonid life-history strategies represent some of the most diverse on the planet. For this reason, salmonids provide an especially interesting model to study the drivers of these different life-history pathways. Over the past few decades, numerous studies and reviews have been published, although most have focused on ultimate considerations where expected reproductive success of different developmental or life-history strategies are compared. Those that considered proximate causes generally focused on genetics or the environment, with less consideration of physiology. Our objective was therefore to review the existing literature on the role of physiology as a proximate driver for life-history strategies in salmonids. This link is necessary to explore since physiology is at the core of biological processes influencing energy acquisition and allocation. Energy acquisition and allocation processes, in turn, can affect life histories. We find that life-history strategies are driven by a range of physiological processes, ranging from metabolism and nutritional status to endocrinology. Our review revealed that the role of these physiological processes can vary across species and individuals depending on the life-history decision(s) to be made. In addition, while findings sometimes vary by species, results appear to be consistent in species with similar life cycles. We conclude that despite much work having been conducted on the topic, the study of physiology and its role in determining life-history strategies in salmonids remains somewhat unexplored, particularly for char and trout (excluding brown trout) species. Understanding these mechanistic links is necessary if we are to understand adequately how changing environments will impact salmonid populations.
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Affiliation(s)
- Kim Birnie-Gauvin
- Section for Freshwater Fisheries and Ecology, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, Silkeborg, 8600, Denmark
| | - Xavier Bordeleau
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, 850 route de la Mer, Mont-Joli, QC, G5H 3Z4, Canada
| | - Steven J Cooke
- Department of Biology & Institute of Environmental and Interdisciplinary Sciences, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
| | - Jan G Davidsen
- NTNU University Museum, Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7491, Norway
| | - Sindre H Eldøy
- NTNU University Museum, Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7491, Norway
| | - Erika J Eliason
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, California, UCSB Marine Science Institute, Building 520, Santa Barbara, CA, 93106-6150, U.S.A
| | - Andy Moore
- Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, Suffolk, NR33 0HT, U.K
| | - Kim Aarestrup
- Section for Freshwater Fisheries and Ecology, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, Silkeborg, 8600, Denmark
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9
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Colgan TJ, Moran PA, Archer LC, Wynne R, Hutton SA, McGinnity P, Reed TE. Evolution and Expression of the Immune System of a Facultatively Anadromous Salmonid. Front Immunol 2021; 12:568729. [PMID: 33717060 PMCID: PMC7952528 DOI: 10.3389/fimmu.2021.568729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/07/2021] [Indexed: 12/24/2022] Open
Abstract
Vertebrates have evolved a complex immune system required for the identification of and coordinated response to harmful pathogens. Migratory species spend periods of their life-cycle in more than one environment, and their immune system consequently faces a greater diversity of pathogens residing in different environments. In facultatively anadromous salmonids, individuals may spend parts of their life-cycle in freshwater and marine environments. For species such as the brown trout Salmo trutta, sexes differ in their life-histories with females more likely to migrate to sea while males are more likely to stay and complete their life-cycle in their natal river. Salmonids have also undergone a lineage-specific whole genome duplication event, which may provide novel immune innovations but our current understanding of the differences in salmonid immune expression between the sexes is limited. We characterized the brown trout immune gene repertoire, identifying a number of canonical immune genes in non-salmonid teleosts to be duplicated in S. trutta, with genes involved in innate and adaptive immunity. Through genome-wide transcriptional profiling (“RNA-seq”) of male and female livers to investigate sex differences in gene expression amplitude and alternative splicing, we identified immune genes as being generally male-biased in expression. Our study provides important insights into the evolutionary consequences of whole genome duplication events on the salmonid immune gene repertoire and how the sexes differ in constitutive immune expression.
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Affiliation(s)
- Thomas J Colgan
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Peter A Moran
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Louise C Archer
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Robert Wynne
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Stephen A Hutton
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Philip McGinnity
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Marine Institute, Newport, Ireland
| | - Thomas E Reed
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
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10
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Archer LC, Hutton SA, Harman L, Poole WR, Gargan P, McGinnity P, Reed TE. Metabolic traits in brown trout ( Salmo trutta) vary in response to food restriction and intrinsic factors. CONSERVATION PHYSIOLOGY 2020; 8:coaa096. [PMID: 33093959 PMCID: PMC7566963 DOI: 10.1093/conphys/coaa096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 09/15/2020] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
Metabolic rates vary hugely within and between populations, yet we know relatively little about factors causing intraspecific variation. Since metabolic rate determines the energetic cost of life, uncovering these sources of variation is important to understand and forecast responses to environmental change. Moreover, few studies have examined factors causing intraspecific variation in metabolic flexibility. We explore how extrinsic environmental conditions and intrinsic factors contribute to variation in metabolic traits in brown trout, an iconic and polymorphic species that is threatened across much of its native range. We measured metabolic traits in offspring from two wild populations that naturally show life-history variation in migratory tactics (one anadromous, i.e. sea-migratory, one non-anadromous) that we reared under either optimal food or experimental conditions of long-term food restriction (lasting between 7 and 17 months). Both populations showed decreased standard metabolic rates (SMR-baseline energy requirements) under low food conditions. The anadromous population had higher maximum metabolic rate (MMR) than the non-anadromous population, and marginally higher SMR. The MMR difference was greater than SMR and consequently aerobic scope (AS) was higher in the anadromous population. MMR and AS were both higher in males than females. The anadromous population also had higher AS under low food compared to optimal food conditions, consistent with population-specific effects of food restriction on AS. Our results suggest different components of metabolic rate can vary in their response to environmental conditions, and according to intrinsic (population-background/sex) effects. Populations might further differ in their flexibility of metabolic traits, potentially due to intrinsic factors related to life history (e.g. migratory tactics). More comparisons of populations/individuals with divergent life histories will help to reveal this. Overall, our study suggests that incorporating an understanding of metabolic trait variation and flexibility and linking this to life history and demography will improve our ability to conserve populations experiencing global change.
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Affiliation(s)
- Louise C Archer
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork T23 XE10, Ireland
| | - Stephen A Hutton
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork T23 XE10, Ireland
| | - Luke Harman
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork T23 XE10, Ireland
| | - W Russell Poole
- Marine Institute, Furnace, Newport, Co. Mayo F28 PF65, Ireland
| | - Patrick Gargan
- Inland Fisheries Ireland, 3044 Lake Drive, Citywest Business Campus, Dublin D24 Y265, Ireland
| | - Philip McGinnity
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23 TK30, Ireland
- Marine Institute, Furnace, Newport, Co. Mayo F28 PF65, Ireland
| | - Thomas E Reed
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork T23 TK30, Ireland
- Environmental Research Institute, University College Cork, Lee Road, Cork T23 XE10, Ireland
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