Char Species Research Articles

Phylogenomic analysis of the Lake Kronotskoe species flock of Dolly Varden charr reveals genetic and developmental signatures of sympatric radiation.

Recent adaptive radiations provide experimental opportunities to parse the relationship between genomic variation and the origins of distinct phenotypes. Sympatric radiations of the charr complex (genus Salvelinus) present a trove for phylogenetic analyses as charrs have repeatedly diversified into multiple morphs with distinct feeding specializations. However, charr species flocks normally comprise only two to three lineages. Dolly Varden charr inhabiting Lake Kronotskoe represent the most extensive radiation described for the genus, containing at least seven lineages, each with defining morphological and ecological traits. Here, we perform the first genome-wide analysis of this species flock to parse the foundations of adaptive change. Our data support distinct, reproductively isolated lineages within the clade. We find that changes in genes associated with thyroid signaling and craniofacial development provided a foundational shift in evolution to the lake. The thyroid axis is further implicated in subsequent lineage partitioning events. These results delineate a genetic scenario for the diversification of specialized lineages and highlight a common axis of change biasing the generation of specific forms during adaptive radiation.

Multiple secondary contacts and historic hybridization between glacial lineages of charr (Salvelinus, Salmonidae) in northeastern Asia

AbstractArctic regions of northeastern Asia represent areas of secondary contact of the glacial phylogenetic lineages of charrs belonging to the genus Salvelinus (Salmoniformes: Salmonidae). However, the post‐glacial dispersion of charr across Arctic regions is poorly understood, as knowledge of populations from Chukotka and its neighbouring areas remains limited. Specifically, there is no clear understanding of which charr species inhabit significant regions of Chukotka from the sea coasts to the Kolyma drainage. In this study, we explored the affiliation of lacustrine charrs from the Chukotka area with (1) the Arctic lineage of Taranetz' charr (Salvelinus taranetzi); (2) the Bering lineage of Northern Dolly Varden (Salvelinus malma malma) and (3) the Siberia and Atlantic lineages of Arctic charr (Salvelinus alpinus). We analysed sequence variation of the mitochondrial DNA control region (mtDNA CR; 960 base pairs) and genotyped seven microsatellite loci of nuclear DNA from charr collected at 13 sampling sites. We found different consequences of secondary contact: (1) complete fixation of introgressed mtDNA (mitochondrial capture) and (2) preservation of several mtDNA lineages with the absence of contemporary gene flow between resident populations. Combining the distribution patterns, phylogenetic network topology and knowledge of the glaciation history of the region, we propose two zones of secondary contact of the glacial lineages in Chukotka–Kolima‐Chukotka River system and Paleo‐Amguema River–from where charrs with introgressed genomes spread throughout this range. However, in some cases, the process of foreign mtDNA capture likely occurs in a more localised manner.

Male lake char release taurocholic acid as part of a mating pheromone.

The evolutionary origins of sexual preferences for chemical signals remain poorly understood, due, in part, to scant information on the molecules involved. In the current study, we identified a male pheromone in lake char (Salvelinus namaycush) to evaluate the hypothesis that it exploits a non-sexual preference for juvenile odour. In anadromous char species, the odour of stream-resident juveniles guides migratory adults into spawning streams. Lake char are also attracted to juvenile odour but have lost the anadromous phenotype and spawn on nearshore reefs, where juvenile odour does not persist long enough to act as a cue for spawning site selection by adults. Previous behavioural data raised the possibility that males release a pheromone that includes components of juvenile odour. Using metabolomics, we found that the most abundant molecule released by males was also released by juveniles but not females. Tandem mass spectrometry and nuclear magnetic resonance were used to identify the molecule as taurocholic acid (TCA), which was previously implicated as a component of juvenile odour. Additional chemical analyses revealed that males release TCA at high rates via their urine during the spawning season. Finally, picomolar concentrations of TCA attracted pre-spawning and spawning females but not males. Taken together, our results indicate that male lake char release TCA as a mating pheromone and support the hypothesis that the pheromone is a partial match of juvenile odour.

DNA Identification of Parasitic Copepods <i>Salmincola</i> (Copepoda, Siphonostomatoida, Lernaeopodidae): Variability and Rate of Evolution of the Mitochondrial Cytochrome c Oxidase Subunit I Gene

The barcode fragment of the COI gene was sequenced in 91 specimens of five species of parasitic Salmincola copepods, sampled from salmonids mainly from the Russian Far East: S. californiensis (mykiss and masu salmon) and S. edwardsii (various species of chars, sockeye salmon from Lake Kronotskoe), S. carpionis (various species of chars), S. markewitschi (whitespotted char), S. stellata (Sakhalin taimen). A total of 41 haplotypes were found with a maximum level of differences of 0.183 nucleotide substitutions per position. The distance between species varied from 0.139 ± 0.014 in the S. markewitschi–S. carpionis pair to 0.179 ± 0.015 in the S. stellata–S. californiensis pair. The intraspecific nucleotide diversity of the COI gene fragment is much lower: for S. californiensis and S. edwardsii, inhabiting the gill cavity and fins of the host – 0.013 ± 0.003 and 0.015 ± 0.003, and for S. stellata, S. markewitschi, and S. carpionis, localized in the buccal cavity of the hosts – 0.002 ± 0.001, 0.004 ± 0.001, and 0.005 ± 0.001, respectively. A comparison of samples of three Salmincola copepod species from different regions of the Russian Far East revealed a significant (Fst = 0.28–0.42, P \( \ll \) 0.001) genetic subdivision. Three subclades of edwardsii-like copepods – S. edwardsii from the Russian Far East, S. edwardsii from the American brook char of eastern North America, and S. siscowet from the lake char of Michigan (COI sequences of copepods from the last two groups are taken from genetic databases) – differed from each other by an average of 9.3–10.9% nucleotide positions, which means the need for a taxonomic revision of S. edwardsii. According to the molecular dating carried out, the divergence of Salmincola lineages started in the Miocene and ended in the early Pliocene. The phylogenetic substitution rate was 0.0228 (95% interval: 0.0132–0.033) nucleotide substitutions/position/million years/lineage. The rate of nucleotide substitutions at the population level is 3.7 times higher – 0.0849 (0.0212–0.170). The high level of variability of the COI gene fragment makes this marker a useful tool both for developing the taxonomy and phylogeny of Salmincola and Lernaeopodidae copepods at the species and genus levels, and for analyzing the differentiation of their populations.

Complete mitochondrial genomes of Gritzenko's charr Salvelinus gritzenkoi and Miyabe charr Salvelinus malma miyabei and their interpretation regarding intraspecific taxonomy.

Salvelinus is one the most species-rich genera of salmonids (Salmoniformes: Salmonidae), and mitogenomic sequence data have served as a rich source of information for resolving fish phylogenies and identifying new charr species. However, current reference databases contain limited mitochondrial genome information on narrow-ranged, endemic charrs with disputable origin and systematic status. More comprehensive mitochondrial genome-based phylogenetics will help enhance understanding of the relationship and delineate charr species. In the present study, the complete mitochondrial genomes of three taxa (S. gritzenkoi, S malma miyabei, and S. curilus) were sequenced (PCR and Sanger dideoxy sequencing) and compared with those of other charr species whose mitochondrial genomes are already reported. Results indicate that the mitochondrial genomes of the three taxa were similar in length (16,652bp and 16,653bp for S. curilus and S. malma miyabei, to 16,658bp for S. gritzenkoi). Analyses of nucleotide composition showed that the newly sequenced five mitochondrial genomes skewed strongly towards high AT (54.4%) content, which is typical of Salvelinus. No large deletions and insertions were found in the mitochondrial genomes, including samples from isolated populations. Heteroplasmy associated with single-nucleotide substitution in the ND1 gene was found in one case (S. gritzenkoi). In maximum likelihood and Bayesian inference trees, S. gritzenkoi and S malma miyabei were clustered with S. curilus with strong branch support. Our results provide the basis for a possible reclassification of S. gritzenkoi to S. curilus. The results of this study may be useful for future genetic studies on charrs of the genus Salvelinus toward the in-depth phylogenetic study and proper assessment of the conservation status of the disputed taxa.

The Ratio of Leukocytes in Peripheral Blood and Immunocompetent Organs of Chars of the Genus Salvelinus (Salmonidae) in the Lake Kronotskoe Basin

The cellular composition of leukocytes in the peripheral blood, head kidney and spleen was studied in individuals of three species of chars of the genus Salvelinus, white char S. albus, long–headed char S. kronocius and long-nosed char S. schmidti, as well as two forms, small-mouth and large-mouth chars living in Lake Kronotskoe. In the studied individuals, the proportion of lymphocytes of leukocytes in the peripheral blood was significant. The forms (species) of chars differed in the proportion of cell types, the size of leukocytes, as well as the intensity of leukopoiesis. The most significant differences in the proportion of different forms of leukocytes were found in the large-mouth char compared to other species and small–mouth char: high content of lymphocytes in blood smears, low content of monocytes in all tissues and organs, blast forms in the blood and neutrophils in the pronephros.

Secondary contact, hybridization, and diversification in Arctic charr (Salvelinus alpinus (L.) species complex) from lakes of the Norilo-Pyasinskaya water system, Taimyr: how many forms exist there?

Secondary contact, hybridization, and diversification in Arctic charr (Salvelinus alpinus (L.) species complex) from lakes of the Norilo-Pyasinskaya water system, Taimyr: how many forms exist there?

Abiotic and Biotic Factors Associated with Sculpin Presence and Density in Northern Idaho Streams

Sculpins (family Cottidae) are a group of small nongame fishes, native to Idaho's colder streams, and have value for biodiversity and as indicators of water quality. We analyzed abiotic and biotic data, including habitat characteristics and presence of co-occurring trout and char (family Salmonidae) species, from 115 streams from the northern Idaho Panhandle to identify the physical characteristics and biotic communities of the streams associated with sculpin presence (or absence) and population density. For comparison, and to determine if the results of the northern dataset could be attributed to the rest of the state, a second dataset from state-wide sampling was also analyzed, as was a subset of both datasets that had no observations of non-native brook trout and rainbow trout. Sculpins were more likely to be present and in higher densities in streams with abundant riffle microhabitats that were mostly free of sediment (identified as Rosgen channel types B, C, and F for northern Idaho and types B and C for the entire state). More sculpins were also found in streams lacking brook trout and rainbow trout. Knowledge of sculpin habitats and the impacts of non-native salmonids may be useful in interpreting water quality evaluations, as well as in improving native fisheries restoration projects and fisheries management for Idaho streams.

Structure evolution of lignite char in step pyrolysis and its combustion reactivity

Step pyrolysis was conducted in a laboratory-scale fixed bed reactor for char preparation. Characterization techniques such as volume solvent swelling, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were applied to reveal char structure evolution during step pyrolysis. Combustion reactivities of the prepared chars were examined at a thermal gravimetric analyzer. Newly formed bond structures in char such as Cal-Cal and Car-Cal/O have been identified at the 1st stage of step pyrolysis, which evidences the occurrence of cross-linking reactions. As a result, step pyrolysis has higher char yield than direct pyrolysis. The char yield from step pyrolysis increases as the 1st stage pyrolysis temperature increases and reaches a maximum at 773 K. An index was put forward to assess the extent of cross-linking reactions during pyrolysis, which is well correlated with char production. The char from step pyrolysis has relatively high graphitization degree than from direct pyrolysis, and thus has lower combustion reactivity. Step pyrolysis can suppress sulfur and nitrogen release in comparison with direct pyrolysis owing to the formation of more stable sulfur and nitrogen species in char. The difference in nitrogen release varies within 8 percentage points and for sulfur release, it is within 5 percentage points under the examined experimental conditions.

Состав лейкоцитов периферической крови и иммунокомпетентных органов белого гольца озера Кроноцкое (Камчатка)

The composition of leukocytes reflects the species features of fish. The ratio of individual cell types reflects the functional state of the organism and the nature of the influence of biotic and abiotic stress factors. Kronotskoye Lake is located in the Far East on the territory of the Kronotsky State Natural Biosphere Reserve (Kamchatka). Due to the peculiarities of the hydrological regime and the relief of the Kronotskaya River basin, anadromous migration along it is limited. Therefore, anadromous fish do not return to the lake after the marine period of their life cycle. The lake basin is inhabited by at least six reproductively isolated forms (species) of chars. White char, Salvelinus albus Glubokovsky, 1977, at the early stages of ontogenesis feeds on invertebrates, and as it grows up, it goes on to a predatory lifestyle. White char migrates around the lake: spawning occurs in the tributaries, and feeding takes place in the lake itself. This work is devoted to the study of the intensity of leukopoiesis and leukocyte composition of the blood, head kidney and spleen of the white char of Lake Kronotskoye. Seven individuals caught using gill nets from July 8 to August 14, 2011 were studied. Peripheral blood was sampled from the tail vein. Sampling also included spleen and head kidney tissues, blood smears and organ-imprinted smears of kidney and spleen. The leukocyte formula and the frequency of occurrence of leukocytes in a peripheral blood smears were calculated using light microscope. The composition of white blood cells in the white char is similar to that of other fish species (lymphocytes, monocytes, neutrophils, and blast cell forms). No basophils or eosinophils were found. In organ-imprinted smears of immunocompetent organs (kidney, spleen), the percentage of lymphocytes is lower and the percentage of blast forms is higher than in the blood leukogram. The abundance index differed from the data obtained in the study of other fish species. English version of the article is available at URL:https://panor.ru/articles/composition-of-peripheral-blood-leukocytes-and-immunocompetent-organs-of-the-white-char-of-lake-kronotskoye-kamchatka/72718.html

Differential gene expression associated with behavioral variation in ecotypes of Lake Superior brook trout (Salvelinus fontinalis)

Associations between behaviors and the development of different life history tactics have been documented in several species of salmon, trout, and charr. While it is well known that such behaviors are heritable the genes and molecular pathways connected to these behaviors remain unknown. We used an RNA-seq approach to identify genes and molecular pathways differentially regulated in brain tissue between “shy” and “bold” brook trout (Salvelinus fontinalis). A small number of genes were differentially expressed between the behavioral types at several months after hatching and two years of age. Pathway analysis revealed that EIF2 signaling differed consistently between shy and bold individuals suggesting large-scale differences in protein synthesis between behavioral types in the brain. Additionally, the RNA-seq data were used to find polymorphisms within the brook trout genome and a GWAS approach was used to test for statistical associations between genetic variants and behavior type. One allele located in a transcription factor (TSHZ3) contained a protein-coding non-synonymous SNP suggesting that functional variation within TSHZ3 is connected to the development of different behaviors. These results suggest that the molecular basis of behavioral development is complex and due to the differential expression of many genes involved in a wide-range of different molecular pathways.

A phosphorous-based bi-functional flame retardant for rigid polyurethane foam

A bi-functional flame retardant for rigid polyurethane foam (RPUF), denoted as PDEP, was designed and synthesized. PDEP contained two phosphorus-based moieties: phosphophenanthrene (DOPO) and a phosphate (DEP), which may exert different functions at different temperatures. DEP and DOPO moieties in sequence decomposed with increasing temperature, continuously releasing and holding high-content phosphorus-oxygen free radicals with quenching effect and producing viscous residues to bond and integrate other char species leading to high barrier effect. The flame retardant modes of action of PDEP was confirmed by experiments using thermogravimetric analysis-Fourier transform infrared (TGA-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), FTIR and SEM. PDEP was incorporated into RPUF system via co-cured with other polyol components. Using expandable graphite (EG) as additive-type flame retardant, an enhanced flame retardancy in RPUF was observed.

Effects of a diatom ecosystem engineer (Didymosphenia geminata) on stream food webs: implications for native fishes

Stream habitat changes affecting primary consumers often indirectly impact secondary consumers such as fishes. Blooms of the benthic algae Didymosphenia geminata (Didymo) are known to affect stream macroinvertebrates, but the potential indirect trophic impacts on fish consumers are poorly understood. In streams of the Kootenai River basin, we quantified the diet, condition, and growth rate of species of trout, char, and sculpin. In 2018, macroinvertebrate taxa composition was different between a stream with Didymo and a stream without, but trout diets, energy demand, and growth rates were similar. Trout abundance was higher in the stream with Didymo, but the amount of drifting invertebrates was higher in the stream without. In 2019, we surveyed 28 streams with a gradient of coverage. Didymo abundance was correlated only with the percentage of aquatic invertebrates in trout diets and was not related to diets of char or sculpin or condition of any species. Thus, we found no evidence for a trophic link between Didymo blooms and the condition or growth of trout, char, or sculpin in mountainous headwater streams.

Conversion and transformation of N species during pyrolysis of wood-based panels: A review.

Understanding the migration and conversion of nitrogen in wood-based panels (WBPs) during pyrolysis is fundamentally important for potentially transforming the N-containing species into valuable material-based products. This review firstly summarizes the commonly used methods for examining N evolution during the WBPs pyrolysis before probing into the association between the wood and adhesives.The potential effects of wood-adhesive interaction on the pyrolysis process are subsequently analyzed. Furthermore, the controversial statements from literature on the influence of adhesives on wood pyrolysis behavior are discussed, which is followed by the detailed investigation into the distribution and evolution of N-containing species in gas, liquid and char, respectively, during WBPs pyrolysis in recent studies. The differences in N species due to the heating sources (i.e. electrical heating vs microwave heating) are particularly compared. Finally, based on the characteristics of staged pyrolysis, co-pyrolysis and catalytic pyrolysis, the converting pathways for WBPs are proposed with an emphasis on the production of value-added chemicals and carbon materials, simultaneously mitigating NOx emission.

Effect of phosphorus (P) on the structure and reactivity of biochars produced from the pyrolysis of acid-washed biomass loaded with P of various forms

This paper investigates the effect of phosphorus (P) on char structure and reactivity of char prepared from the fast pyrolysis of purposely-prepared P-loaded biomass samples at 1000 °C in absence of other inorganic species. Biomass was first acid-washed then loaded with P of three different occurrence forms (one organic P i.e. phytic acid, and two inorganic P i.e. orthophosphoric acid and polyphosphoric acid) at the same P content of 0.8 wt%. Experimental results show that both organic and inorganic P substantially increase char yields during pyrolysis from 6.2% for the biomass sample without P to 23.0–26.0% for P-loaded samples due to the enhanced crosslinking by P-containing structures in char, leading to increases in the char C and H contents and decrease in O content. The presence of P in biochars from fast pyrolysis of various P-loaded biomass samples plays important role in the evolution of char structure and intrinsic reactivity measured during low-temperature oxidation at 500 °C in air under chemical-reaction-controlled regime. After pyrolysis and subsequent char oxidation, all P in biomass either as organic or inorganic P are found to be present in forms of acid-insoluble organic structures. For char prepared from acid-washed wood, char reactivity increases with char conversion due to the increasing pore surface area at higher conversion. Comparatively, for char prepared from acid-washed wood loaded with various P at char conversion below 60%, the presence of P increases char intrinsic reactivity due to the enhanced crosslinking of reactive carbon structures and reduced condensation of char structures. However, at conversions above 60%, P-containing species in char lead to a significant decrease in char reactivity, due to the formation of abundant CO-P bonds, that is highly resistant to the oxidation in air, in the reacting chars.

Peculiarities of Early Ontogenesis of Nose Char (N1-form), Endemic Lacustrine and Riverine Form of Salvelinus malma Complex (Salmonidae), of the Lake Kronotskoe (Eastern Kamchatka, Russia)

The growth, order of anlage, and features of transitive stages of skeletal elements (cranial bones and serial structures: teeth, gill rakers, fin rays, pterigyophores, vertebrae muscles, predorsalia, and scales) in were studied in pre-larvae, larvae, and fingerlings of the nose char (N1-form), endemic lakustrine-riverine form of the Dolly varden Salvelinus malma complex of the Lake Kronotskoe, reared in the laboratory at a constant temperature. A comparative analysis of the early ontogenesis of sympatric species of nose char and white char of the Lake Kronotskoe evidences on a high similarity in the growth rate and development of the two forms, differing by the body length of free embryos and the larvae coloration.

On the Origin of Two Species of Charrs (Salvelinus, Salmonidae) in Lake Elgygytgyn: Data on the ATPase6–NADH4L Region of Mitochondrial DNA

To test the reliability of Restriction Fragment Length Polymorphism data for ATPase6–NADH4L region of mitochondrial DNA (2162 bp), which unambiguously support the allopatric origin of the small-mouth charr Salvelinus elgyticus and “Boganida” charr S. “boganidae” in Lake Elgygytgyn, this region was sequenced in some members of the S. alpinus–S. malma complex. It is shown that RFLP data on the number of restriction sites and the size of restriction fragments for the 2162 bp region are poorly consistent with data on nucleotide sequences for the majority of forms and species of charr. Based on the identified errors, data on the MvaI restriction sites for ATPase6–NADH4L region of mitochondrial DNA cannot be considered as unambiguous evidence in favor of the allopatric origin of the two charr species in Lake Elgygytgyn. Nevertheless, the nucleotide data for this fragment suggest with a high probability that the small-mouth and “Boganida” charrs of Lake Elgygytgyn have an allopatric origin.

Rediscovery of a presumed extinct species, Salvelinus profundus, after re-oligotrophication.

Lake Constance (47° 38’ N, 9° 22’ E) is a deep (max. depth 251m) and large (surface area 536 km2) postglacial lake in Central Europe. Originally, it harboured two charr species – Salvelinus umbla and S. profundus. The first is a medium-sized, colourful, winter spawning charr, which is widespread across Central European lakes, the second a small, pale, summer spawning, deepwater charr, which is endemic to Lake Constance (Schillinger 1901, Kottelat and Freyhof 2007). S. profundus has exceptionally large eyes and the upper jaw strongly overlaps the lower jaw. These traits are both considered adaptations to its life in the deep where it mostly feeds on profundal benthos (Schillinger 1901). During the second half of the last century, Lake Constance became eutrophic, resulting in oxygen-depletion in deep waters (IGKB 2004). The anoxic conditions harmed the development of eggs by profundal spawning fish (Baer et al. 2017). Thanks to strict management interventions, the lake has returned to an oligotrophic state, and oxygen is again available in the water column down to the greatest depth (IGKB 2004).

A comparison of turbine entrainment rates and seasonal entrainment vulnerability of two sympatric char species, bull trout and lake trout, in a hydropower reservoir

AbstractPotadromous salmonids that reside in hydropower reservoirs often have a high recreational and conservation value. However, the potential seasonal turbine entrainment vulnerability patterns of potadromous salmonids are not well understood. Here, we use acoustic telemetry to test the hypothesis that adults of two species of the Salvelinus genus (bull trout and lake trout) differ in their seasonal patterns of entrainment and entrainment vulnerability over a 2‐year period. Our results show that while both species were entrained at similarly low annual rates (~1%), these two salmonids differed in their patterns of forebay residency and proximity, with implications for entrainment risk. Bull trout occupied the forebay at low rates across all seasons, with no clear seasonal pattern of forebay proximity. In contrast, lake trout displayed a strongly seasonal pattern of entrainment vulnerability with a distinct movement away from the forebay during the summer, and a large increase in forebay proximity and use in the winter and spring. These findings provide a novel species‐specific demonstration of the potential entrainment vulnerability of lake trout. The seasonal patterns of entrainment vulnerability seen in previous bull trout studies, where bull trout occupied top pelagic predator niches, were not replicated in our study where bull trout occur in sympatry with another top pelagic predator. These findings, which indicate that species composition plays an important role determining entrainment vulnerability, have important implications for the conservation of indigenous lake trout and bull trout populations, and together highlight the need for a site‐specific approach to entrainment quantification.

Invasions of rainbow trout and brown trout in Japan: A comparison of invasiveness and impact on native species

AbstractMany species of salmonids have been stocked into waters outside of their native range. The invasiveness and impact of these species on native species varies depending on their biological traits, and on environmental conditions, such as climate. In Japan, rainbow trout and brown trout, both listed in 100 of the world's worst invasive alien species by the International Union for Conservation of Nature, occur as non‐native species. The invasiveness of these two species is thought to be related to seasonal flooding, given flood waters can physically damage fry and prevent population establishment. Rainbow trout have successfully invaded waters in Hokkaido, northern Japan, where the likelihood of flooding is low between June and July, when their fry emerge, but successful invasions are rare in regions south of Hokkaido. Brown trout, however, have successfully invaded waters not only in Hokkaido, but also other regions. Since brown trout have a similar life history to the native white‐spotted charr and masu salmon, with fry emerging before the flood season, they are more suited to the Japanese climate than Rainbow trout. Rainbow and brown trout interact with native species in various ways, but a common outcome of these interactions is the displacement of native charr species. Legal regulations of non‐native salmonids should be based on understandings of the ecological traits of each invasive species and regional impacts on native species. Given the ongoing nature of climate change, the nature and extent of the effects of rainbow and brown trout on native species might also change.