Schizothorax Richardsonii Research Articles

Reference intervals for haematological and serum biochemical indices in vulnerable Himalayan Snow trout, Schizothorax richardsonii, inhabiting the Indus tributary of Ladakh Trans-Himalayan region, India

Reference intervals for haematological and serum biochemical indices in vulnerable Himalayan Snow trout, Schizothorax richardsonii, inhabiting the Indus tributary of Ladakh Trans-Himalayan region, India

Unveiling climatic niches for deeper insights into invasion potential and enhanced distribution models of freshwater fishes

AbstractIntroduced species may exhibit variations in their preferred climatic niches between their native and introduced ranges, which can have important implications for the transferability of distribution models. In the Himalayan ecoregion, little is known about the geographic distribution and climatic niche overlap between native and introduced cold‐water species. Here, we used the COUE (centroid shift, overlap, unfilling, and expansion) framework to explore the invasive potential of rainbow (Oncorhynchus mykiss) and brown (Salmo trutta fario) trout and corresponding climatic niche overlap with native snow trout (Schizothorax plagiostomus and Schizothorax richardsonii) in the Indus and Ganges River basins. Although we found more stability in the climatic niche for O. mykiss (93%) than S. trutta (58%), both species do not conserve their climatic niches in this region (p > 0.05). S. trutta has expanded more toward new environmental conditions (42%) compared to O. mykiss (7%). However, there are still available environmental gaps that O. mykiss and S. trutta can potentially occupy in the future. There was a higher overlap in climatic niches between S. plagiostomus and O. mykiss and between S. richardsonii and S. trutta. Observed shifts in climatic niches of these introduced species can negatively affect the transferability of distribution models, which may underestimate the assessments of habitat suitability for introduced trout in the Himalayas. Our study demonstrates that the information on climatic niche dynamics can inform the model‐building process and improve the transferability and predictive performance to better assess vulnerability of sensitive habitats to introduced species in the Himalayas and elsewhere.

Swimming Performance of Schizothorax sp. and Planning of Fish Passages in Nepal

Swimming performance of migrating fish is crucial for the planning and design of effective fish passages. Commonly the fish swimming speeds are classified into five categories: 1) Optimum Swimming Speed, 2) Maximum Sustained Swimming Speed, 3) Critical Swimming Speed, 4) Maximum Domed Swimming Speed, and 5) Burst Swimming Speed. Swimming characteristics are related to the different species' adaptions to the environmental conditions. A variety of different factors affect the swimming capacity of fish which is directly related to fish size and species-specific morphology. A crucial abiotic factor is water temperature, which affects the fish physiology and thereby the swimming speed of the fish. This means that the fish's swimming speed can increase with increased water temperature. The swimming speed also increases with fish size. Fish often use burst speeds when passing a step in a fish ladder or entering a culvert. Burst speed is the highest speed attainable for fish, and it is the maximum energy output to be gained by using the white muscle (red muscle in salmonids). The burst speed can only be maintained for short periods of time (seconds). In the Himalayas, the main objective of many fisheries development plans is to secure future habitats and ensure up- and downstream migration of fish. Schizothorax richardsonii is often a targeted species in the area due to its importance as a food resource. If a fish passage is prepared for the upstream migration of fish, it is also crucial for the fish population development to ensure a safe downstream passage. Data on swimming performance for many of the native fish species in Nepal are scarce which complicates the design of suitable ecologically adapted fishways. In general, nature-like fish passes allow most of the species to migrate, followed by vertical slot fishways, meander fishways, and thereafter fish ladders of the pool-and-weir type. The key factor is to construct fish-passes that under all naturally required environmental circumstances can allow appropriate passage conditions of the targeted fish species.

Microplastic in fishes: the first report from a Himalayan River - Alaknanda.

The present study aimed to understand microplastic (MP) ingestion by five fish species with different feeding habits namely, Schizothorax richardsonii and Crossocheilus latius (herbivore),Cyprinus carpio (omnivore), Tor chelenoid (herbi-omnivore), and Botia horii (carnivore). The fishes were sampled from River Alaknanda (one of the headwaters of River Ganga) patch at Srinagar, Garhwal, Uttarakhand. The fish gut samples were digested with 30% hydrogen peroxide and vacuum filtered through glass microfiber filter. Each filter paper was observed microscopically to count MPs, and then, selected MPs were chemically characterized using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The results revealed that all the species were contaminated with MPs and the rate of MP ingestion varied with feeding habits. The herbi-omnivore fish, Tor chelenoid, was observed to have the highest MP ingestion. Among the analyzed particles, fibers (66%) were the dominant type of MPs. The MPs were chemically characterized as High-Density Polyethylene (HDPE), Polypropylene (PP), and Polyester. This study contributes as a reference for the forthcoming researches, as it is the pioneer work on the ingestion of MP by fishes of a Himalayan River.

Triploidy verification of Schizothorax richardsonii using erythrocyte cell and nucleus measurement

The individuals of diploid and triploid Schizothorax richardsonii (Gray, 1832) were identified using erythrocyte indices. The Erythrocyte cell's major axis of the triploid was 17% higher than the diploid. The increase in the nucleus major axis size of the erythrocyte of the triploid was also greater by 8% concerning the diploid fishes. The erythrocyte measurement ranged between 13.29±1.06 to 14.45±0.97 for diploid 15.91±1.32 to 16.49±1.23 for triploid erythrocyte nucleus 6.16±0.67 to 6.40±0.63 and 6.70±0.71 to 6.94±0.56 for diploid and triploid respectively. The data were analyzed by One Way of Analysis of Variance (ANOVA) for both diploid (control) and triploid (treated) erythrocyte and nucleus measurement which showed significant differences with p<0.05. These parameters, thus, can successfully be used in discriminating diploid and triploid S. richadrsonii.

Habitat overlap among native and introduced cold-water fishes in the Himalayas

Fish invasions threaten native freshwater ecosystems worldwide, yet methods to map biodiversity in data-deficient regions are scarce. Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) have been introduced to the Himalayan ecoregion where they are sympatric with vulnerable native snow trout Schizothorax plagiostomus and Schizothorax richardsonii. We aim to evaluate potential habitat overlap among snow trout and non-native trout in the Indus and Ganges River basins, Himalayan ecoregion. We transferred maximum entropy (MaxEnt) models developed with spatially continuous freshwater-specific environmental variables to map the distribution of potentially suitable habitats for rainbow and brown trout in the Himalayas. We adopted a similar procedure to map suitable habitats for snow trout species. There were substantial habitat overlaps (up to 96%) among snow trout and non-native trout. Yet, the physiography of receiving basins could play a role minimizing the impacts of each non-native trout on native snow trout. We generate high-resolution classified stream suitability maps as decision support tools to help managers in habitat allocation and policy formation to balance recreational fisheries with conservation of snow trout. Our workflow can be transferred to other basins and species for mapping freshwater biodiversity patterns in species-rich yet data-poor regions of the world.

Microplastics in the River Ganga and its fishes: Study of a Himalayan River

The River Ganga has been explored for microplastics (MPs) majorly in the lower or middle course, while the upper course from where the river starts its journey remains untouched. This study investigates the occurrence and distribution of MPs in the river environment (water and sediment) and common fishes inhabiting the upper stretch of River Ganga in the Uttarakhand state of India. A volume-reduce method by using sieve filtration was used to take water and sediment samples from the study area while fish samples were collected using net method. The samples underwent alkali digestion, microscopic examination, and chemical analysis using Fourier Transformed Infrared Spectroscopy (FTIR). An average of 118.5 ± 49.65 particles per 1000 L and 131.5 ± 53.60 particles/kg dry weight were found in water and sediment respectively. While in the fishes, Tor tor, Schizothorax richardsonii, Labeo dero and Gara gotyla gotyla MPs were 53.13 ± 63.77, 36.33 ± 22.34, 15.42 ± 9.33 and 12.63 ± 5.93 particles/individual respectively. A positive correlation was observed between the number of MPs in fish and their body length, weight, and gut weight, while no correlation was found between feeding habit and MP accumulation. The majority of MPs detected were fibers ranging from 100 μm to 1 mm in size. Polymer types varied among water, sediment, and fish samples, with polyethylene (PE) predominant in water, polypropylene (PP) dominant in sediment, and polyethylene terephthalate (PET) and polystyrene (PS) most abundant in fish samples.

Status of fish assemblage structure in the Ganga and Indus riverine systems of the western Himalaya

AbstractThe Ganga and Indus riverine systems are the major freshwater resources in the western Himalaya. The aim of this review was to critically analyze the status of inland fisheries in both the Ganga and Indus Riverine systems of the western Himalaya. Data from secondary sources such as research publications, scientific documents, technical advisories, and books were retrieved. The fish diversity of both riverine systems reveals that the number of endemic and native species like Tor tor, Tor putitora, Glyptothorax spp., Nemacheilus spp., and Schizothorax richardsonii is decreasing. Moreover, in most of the rivers of both riverine systems, exotic species, especially those belonging to the Cyprinidae family, for example, Cyprinus carpio, are increasing and are also dominant, followed by the families Cobitidae and Sisoridae. The Ganga and Indus riverine systems' diverse fish populations have declined because of various anthropogenic activities, especially water pollution and dam construction, which are responsible for the change in river hydrology. Frequent data were available on the Ganga riverine system, which shows a continuous decline in fish diversity. A similar trend was observed in the lower stretches of the Indus riverine system. But negligible information was available on the upper stretches of the Indus riverine system; this may be due to a large research gap. However, adequate knowledge of both river systems is necessary to develop conservation and management strategies for the sustainable development of fishery resources in India in the future.

A review on the threatened species of snow trout Schizothorax richardsonii Gray, 1832 (Cypriniformes: Cyprinidae): From the climate change and conservation perspectives

Snow trout (Schizothorax richardsonii Gray, 1832) occupies the Himalayan domain from the foothills to 3000 m and inhabits all types of water bodies, like rivers, rivulets, lakes, and reservoirs. It is a rheophilic fish species that can thrive in a wide range of ecological and climatic conditions. Globally snow trout is now a 'threatened' species. Invasion of its natural habitats by exotic trouts, river valley hydropower projects as well as destructive fishing in the Himalayan region have long been attributed to the vulnerability of this species. The intrinsic characteristics of snow trout also make it a weak competitor in the Himalayan rivers. Climate change coupling with above mentioned threats poses a new challenge for Himalayan fish, especially snow trout, as it is confined to the Himalaya. Given these threats, an intense drive for snow trout conservation is urgently required. This contribution is an attempt to find out solution to this fact. In line with the opinions of ecologists and conservationists, we suggest a few measures like setting up free-flowing and undammed rivers as 'fish conservation zones', environmental flow to downstream areas of existing dams, prohibition of stocking of exotic fish species in natural habitats and use of hatcheries for stocking and restocking of snow trout in the rivers for the conservation of the species. Keywords: Climate change, Conservation, Himalaya, Hatcheries, Snow trout, Threats, Vulnerable

A Report on The Incidence of Myxozoan Parasite in Schizothorax Richardsonii (Gray) from Uttarakhand, India

A Report on The Incidence of Myxozoan Parasite in Schizothorax Richardsonii (Gray) from Uttarakhand, India

Detection of body shape variations in vulnerable snow trout, Schizothorax richardsonii (Gray, 1832) from rivers of the Indian Himalayan Region

Species population structure and composition are components of essential biodiversity variables (EBVs) to measure change in global freshwater diversity. Multiple stressors affect the population structure of coldwater fishes in the Indian Himalayan Region (IHR). In this study, 463 individuals of snow trout, Schizothorax richardsonii were collected from 14 locations on seven rivers of IHR (Satlej, Chenab, Beas and Ravi rivers of Indus basin, and Bhagirathi, Alaknanda and Kosi rivers of Ganges basin) to assess the inter and intra-basin population-level shape variation through landmark-based “geometric morphometrics”. Procrustes ANOVA on the superimposed shape coordinates revealed significant relationship (F = 4.51, p < 0.05) among groups. Principal component analysis (PCA) accounted for 42.37% of the total variance (22.69% for PC1, 19.68% for PC2), indicating overlapping among populations. Canonical variate analysis (CVA) accounted for 66.71% of the total variance (37.07% for CV1 and 29.64% for CV2), indicating non-overlapping between basins and within Ganges basin, and overlapping within Indus basin. Pair-wise distances extracted from PERMANOVA also found to be non-significant (p > 0.05) between Satlej, Chenab, Beas and Ravi rivers, indicating overlapping of samples within the Indus basin, and significant (p < 0.05) between rivers of Indus basin, Alaknanda, Bhagirathi and Kosi river systems, indicating non-overlapping of specimens between these rivers. Overall, results of multivariate analysis indicated four heterogeneous populations of snow trout in the selected rivers based on their shape: 1. Indus basin comprising of Satlej, Chenab, Beas and Ravi rivers, 2. Bhagirathi River, 3. Alaknanda River and 4. Kosi River. This study will be useful in stock identification, and provide a key to climate change and demographic research for developing sustainable management strategies to conserve this threatened species.

Herbal Feed Additives for Gonadal Maturity and Breeding Performance of Female Snow Trout (Schizothorax richardsonii) in Captive Condition

Addressing the issue of gonadal maturity and breeding in captive condition for a commercially important indigenous Coldwater fish, snow trout, Schizothorax richardsonii, field study was conducted with dietary supplementation of the blend of Ashwagandha (Withania somnifera) root powder, dried powder of garlic (Allium sativum), and hing (Ferula asafoetida). Experimental fish of 3 years age were reared in FRP tanks (n = 4) of 1200 L capacity with stocking density of n = 60 in each tank and fed with control (CD) and experimental (TD) diets in duplicate at the feeding rate of 3–5% of their body weight twice in a day. Gonadosomatic index (GSI) and hepatosomatic index (HSI) were recorded for annual breeding cycle coupled with breeding indices in breeding season and regular monitoring of water quality parameters. In female stock, the GSI values ranges from 0.87 to 12.83 and 1.84 to 15.42 in control and treated groups, respectively. Two peaks of GSI values reflects the two breeding season of the species during the month of March and September. Similarly, HSI was lowest during the month of March and September in captive reared female fish and highest during the month of May to June and January to February, with similar trend in both, control treated and groups. In captive condition, 80% specimens were observed mature for spawning in treated group, while only 15% females were ready to spawn in control stock. The fecundity of the fish was observed in the range of 20210-23710 eggs/kg body weight with 80–94.2% fertilization rate. The egg size was observed in the range of 3.5–3.8 mm. The study revealed that 1.0% supplementation of blend of herbs in the diet is beneficial for gonadal maturity of females and better spawning of S. richardsonii in captive Coldwater condition.

The morphological and molecular description of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. from Schizothorax richardsonii (Gray) in Poonch, Jammu and Kashmir, India

Specimens of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. are described from Schizothorax richardsonii (Gray) in the Poonch River, Jammu and Kashmir. Specimens are thick-walled with dissimilar dorsal and ventral para-receptacle structures, anteriorly manubriated hooks, two giant nuclei in each lemniscus and many subcutaneousy. The lemnisci barely overlap the larger anterior testis, the cement gland has eight giant nuclei, and the seminal vesicle is large with thin walls. The vagina is unremarkable but the long uterus is made up of four specialised regions. Neoechinorhynchus rigidus (Van Cleave, 1928), resembles N. poonchensis sp. n. It is distinguished from N. poonchensis sp. n. by having smaller trunk, proboscis, and male reproductive structures, equal testes, unequal lemnisci with three giant nuclei each, and much larger anterior proboscis hook (130 μm in males) than that originally described by Van Cleave (1928) (70 μm in a female). Anterior hook length alone is sufficient to conclude that the N. rigidus of Datta (1937) is not the same species as the N. rigidus of Van Cleave (1928). Van Cleave's (1928) species remains valid and that of Datta (1937) is considered a different species named Neoechinorhynchus pseudorigidus sp. n., herein. Micropores of N. poonchensis sp. n. have variable distribution in different trunk regions and the Energy Dispersive X-ray analysis demonstrated higher levels of sulfur and lower levels of calcium and phosphorus. Sequences of the 18S rDNA gene from nuclear DNA, and cytochrome c oxidase subunit I (cox1) from mitochondrial DNA of N. poonchensis sp. n. were amplified and aligned with other sequences available on GenBank. Maximum likelihood (ML) and Bayesian inference (BI) analyses inferred for 18S rDNA and cox1 showed that N. poonchensis sp. n. was nested in a separate clade.

Trace elements in fish species: Schizothorax richardsonii, Salmo trutta and Neolissochilus hexagonolepis in relation to sizes and tissues of Punatsang Chhu

Three fish species ( Schizothorax richardsonii, Salmo trutta and Neolissochilus hexagonolepis ) were collected from Punatsang Chhu river and sample tissues of muscles and gills were analyzed for Al, As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Se, Sr and Zn using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Principal Component Analysis (PCA) for each species grouped elements with higher concentration in gills compared to muscle tissues. The Man-Whitney test revealed significant difference between tissues sources and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn in S. richardsonii , Al, Ba, Co, Fe, K, Mn, Ni, Sr and Zn in S. trutta and Al, Ba, Co, Cr, Fe, K, Mn, Sr and Zn in N. hexagonolepis. The Kruskal-Wallis test for inter-species variation revealed significant difference in concentration of As, Cr, Cu, Fe, Mn, Ni and Zn in muscle tissues and Ba, Cr, Cu, Mn, Sr and Zn concentrations in gills of three species. Spearman correlation between levels of elements and fish size (weight and length) revealed positive and negative relationships for concentrations of As, Ba, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, Sr, and Zn and concentrations of Al, Ba, Cd, Co, Fe, K, Mn, Mo, Ni, Sr and Zn respectively, both at p < 0.001 and p < 0.005. • Sixteen trace elements analyzed in tissues of the three fish species using ICP-OES. • Significant differences in concentration of trace elements in gills and muscle tissues of three fish species. • Strong to moderate of both positive and negative correlations between fish sizes and concentration of trace elements. • Interspecies concentration significantly different for most of the trace elements. • MPI observed highest in Schizothorax richardsonii for both gills and muscle tissues compared to other two species.

Current Status of Ichthyo-Faunal Diversity of Glacier Fed Stream Balkhila from Garhwal Himalaya

The present paper deals with the study of ichthyo-faunal diversity of glacier fed stream Balkhila. The stream Balkhila is an important tributary of Alaknanda River of Garhwal Himalaya. After its origin from the Lal Mati glacier, it drains through the famous Mandal valley of Garhwal region. The stream was represented by 10 fish species belonging to 3 families namely Cyprinidae (Schizothorax richardsonii, Schizothorax plagiostomus, Schizothoraichthys niger and Tor chelynoides), Cobitidae (Noemacheilus rupicola, N. montanus, N. denisonii and N. multifasciatus) and Sisoiridae (Pseudecheneis sulcatus and Glyptothorax pectinopterus). Among all these fishes Schizothorax richardsonii was abundant in the stream. The Schizothorax plagiostomus was common fish of the stream, whereas, rest all other fishes of the stream were found in less number. The relative abundance was calculated to show the abundance of different fish species of the stream. The various habitat preferences of different fish species were also studied. The diversity indices such as Shannon-Wiener diversity index, Simpson index, Margalef index and Sorensen’s similarity index was also calculated.

The study of effect of vitamin C and Achyranthes aspera seeds enriched diets on the growth, biochemical composition, digestive enzyme activities and expressions of genes involved in the biosynthesis of fatty acids in Snow trout Schizothorax richardsonii (Gray, 1832)

ABSTRACT Snow trout, Schizothorax richardsonii (Gray, 1832), is an economically important fish in the Himalayan region. Snow trout fry (118.53 ± 5.42 mg) were cultured in flow-through systems for 60 days. Fry were fed with four different diets containing: 0.08% vitamin C (D1), 0.5% Achyranthes aspera seeds (D2), both vitamin C and seeds (D3), and a control (D4). Average weight (271.82 ± 4.90 g) and specific growth rate (1.39 ± 0.03) were significantly higher in fish fed D3 compared to the others. Digestive enzyme activities were significantly higher in D3 compared to the others. EPA content was significantly higher in D2 (110.33 ± 0.94 mg 100 g−1) and D3 (109.87 ± 1.87 mg 100 g−1); DHA (342.70 ± 0.77 mg 100 g−1) and n-3 PUFA (496.17 ± 1.82 mg 100 g−1) contents were significantly higher in D3 compared to the others. The expression of fads2d6 was significantly higher in D3 (6.70-fold) and elovl5 in D2 and D3 (1.51–1.45-fold) compared to the others. Enriched diets improved fish flesh composition.

Herbal Feed Additives for Gonadal Maturity and Milt Quality in Males of Snow Trout (Schizothorax richardsonii)

Herbal Feed Additives for Gonadal Maturity and Milt Quality in Males of Snow Trout (Schizothorax richardsonii)

Dendritic prioritization through spatial stream network modeling informs targeted management of Himalayan riverscapes under brown trout invasion

Abstract With the concept of ‘riverscapes’ long pending to be acknowledged in the ‘landscape‐centric’ legislative framework of Himalayan nations, conservation of native riverine species stays practically unheeded. This necessitates urgent prioritization of stream networks to conserve the lotic taxa under invasion pressures. Himalayan riverscapes are pervaded with the invasive‐exotic brown trout Salmo trutta, posing serious threats to the co‐occurring native, the snow trout Schizothorax richardsonii. Using intensive surveys (218.7 km) and geostatistical stream network models (n = 537), we contrasted snow trout in two stream networks with and without invasives, for assessing differences in their spatial distribution. Our models indicate invasion‐induced relegations of natives from the river mainstem into headwaters, with large sections of mainstem occupied by invasives. Furthermore, a concerningly small percentage of potential habitat left for natives to occupy in the mainstem is threatened, where a 100% overlap of native and invasive trout distributions is predicted. With a higher presence probability for the natives in headwaters of invaded watershed as compared to the non‐invaded watershed, we highlight the headwater streams as potential refugia for the natives under invasion. Synthesis and Applications. Our approach of basin‐scale dendritic prioritization provides immediate management solutions to tackle brown trout invasion threats in Himalaya. We inform decisions on delineation of headwaters as invasion refugia for native fish, with assisted recovery of their fragmented populations in the river mainstems through targeted management of invasives.

Morphometric and molecular identification ofArgulus japonicus(Thiele 1900) in vulnerable Himalayan snow trout,Schizothorax richardsonii(Gray 1832)

Argulus is a crustacean branchiuran parasite that causes severe problems in aquaculture throughout the world. Conventionally, Argulus spp. are identified through the morphological descriptions. In the recent years, polymerase chain reaction amplification with nuclear ribosomal RNA sequence coupled with morphological description is becoming standard for the species-level identification of Argulus spp. The present study investigated Argulus sp. in snow trout, Schizothorax richardsonii, using morphological and molecular tools. Morphologically, the parasite had branched dorsal ridges of the carapace, clubbed shaped anterior respiratory area, curved shaped posterior respiratory area, three relative sharp teeth and chitinous shovel peg on the fourth swimming appendages. Females Argulus sp. were larger in size than males in their length and width. Morphological characteristics and 18s rRNA study revealed that the parasite species was Argulus japonicus. A phylogenetic tree was constructed to examine relationships between these A. japonicus sequences and existing archived sequences. The maximum distribution of pathogenic argulid was observed in the dorsal fin, followed by the ventral fin and pectoral fin. The present study contributes to the first species-level morphological and molecular identification of A. japonicus in vulnerable Himalayan snow trout, S. richardsonii.

Invasive brown trout Salmo trutta induce differential growth strategies in the native snow trout Schizothorax richardsonii of Himalaya: Are natives in unaltered rivers better at picking the gauntlet of invasion?

Brown trout Salmo trutta is a potent global invader and its establishments have progressively altered physiologies, life-histories and niche-availabilities for native fish species. River impoundments further escalate its invasion potential. The Himalayan rivers however, stay uncharted for the effects of brown trout interactions with the native fish fauna. Snow trout Schizothorax richardsonii a Himalayan cold-water native, concerningly overlaps its range with brown trout. To understand its responses to invasion pressures, we investigated brown trout effects on the age and growth of snow trout populations in three rivers with varying levels of perturbation: (a) a dammed and (b) an undammed river with the invasive brown trout in comparison to (c) an undammed river without invasion pressures. We found sympatric snow trout in the undammed river to respond to brown trout invasion with fast life history responses, showing an early age-at-maturity (A50 = 1.2 years) and fast growth with a higher growth constant (K = 0.40 yr−1) and specific rate of linear growth across life. On the contrary, sympatric snow trout in the dammed river showed an explicitly slow life-history by maturing at a higher age (A50 = 2.9 years) and a slow growth, with a lower growth constant (K = 0.26 yr−1) and specific linear growth rates. Our findings suggest that, the snow trout appear to present stronger response to brown trout invasions when the river is unaltered and free from hydropower operations and damming. Further research is strongly warranted from other high-altitude Himalayan basins to delineate the variation in growth strategies exhibited by snow trout in sympatry with the invasives.