Mahseer Species Research Articles

Analysis of Phylogenetics and Structural Relationships of the Cytochrome b Gene Protein in Mahseer Fish (Tor sp.)

Abstract The Cytochrome b gene from mitochondrial DNA encodes a protein that can be used as a genetic marker to identify species. This study aims to determine the bioinformatic characteristics of the gene encoding Cyt b isolated from various Mahseer species, Tor tambroides, Tor douronensis, Tor khudree, and Tor putitora. Mahseer Cyt b sequences can be used for detailed computational investigation of the properties of 3D protein models and phylogenetics. The data analysis technique uses nucleotides with a sequence length of 330 bp obtained from NCBI. The MEGA X program was used for phylogenetic analysis. 3D protein structure predictions were obtained through the Swiss model and protein homology program using PYMOL software. The results of phylogenetics show close kinship relationships with the closest genetic distance of 0.000, while the farthest distance is 0.068. The nucleotide composition contains Thymine (30.23%), Cytosine (25.81%), Arginine (28.05%), and Guanine (15.92%). 3D modeling of the Cyt b protein Mahseer referring to the species Neolissochilus hexagonolepis (McClelland, 1839). The 3D protein structure prediction was assessed via a Ramachandran plot of 99.07%. This study can be used as a reference to support sustainable conservation efforts by observing the populations and habitat conditions.

Insights on the distribution, catch and release and public sentiment towards recreational angling of mahseers—A study of YouTube videos from India

Abstract Masheers are a group of large‐bodied freshwater fishes popularly known as the ‘Tiger of Rivers’. Their size and fighting power make them one of the most popular game fishes and a dream catch of many recreational anglers in the Indiansubcontinent. The present study explored the recreational angling (RA) videos of five mahseer species (Tor khudree [Deccan mahseer], Tor putitora [golden mahseer], Tor remadevii [humpback mahseer], Tor mosal [mosal mahseer] and Neolissochilus hexagonolepis [chocolate mahseer]) recorded from India and uploaded on the social media platform YouTube from January 2010 to October 2022. We did not come across any RA videos of T. mosal and T. remadevii; hence, further analyses were carried out on the remaining three focal species. No seasonality was observed in the frequency of RA videos uploaded on YouTube, and T. khudree attracted the highest number of views per video. Catch and release, an ethical RA practice, was noticeably low in the case of N. hexagonolepis. The length of catch was found to be positively associated with the social engagement received by the RA videos of all three mahseer species. Angler‐ and angling‐related remarks and words associated with positive emotions (trust, joy and anticipation) dominated the comments received by the angling videos. The results are discussed in light of the trending discourses on developing social media data as a complementary tool for monitoring and managing RA and conserving fish.

Morphometric and Molecular Assessment of Tor putitora and Neolissochilus hexagonolepis Population in Jia Bhoroli river Ecotone Zone, Assam

Background: Ecotones are areas of overlap between different ecosystems, referred to as ‘junction zones or tension belts’, that harbor a distinct collection of organisms. Tor putitora and Neolissochilus hexagonolepis are two threatened Mahseer species which requires urgent conservation attention. Bhalukpung area in the River Jia Bhoroli is an ideal example of an ecotone, as its ecosystem transforms from resembling a foothill river ecosystem to a river floodplain ecosystem. However, studies on threatened fish populations in ecotone zones, which could be used as conservation sites, are lacking. Therefore, the present study aims to generate firsthand information on the relationship between the populations of these threatened fish and their foothill-floodplain river interface ecotone in the Jia Bhoroli River. Methods: The data on water quality, topography was collected for a period of one year from January to December, 2021 along with fish samples. The mahseer species were identified and catch per unit effort (CPUE) was also calculated. Result: Identification of the collected mahseer fish as T. putitora and N. hexagonolepis were confirmed using both morphometric as well as molecular tools. CPUE was found to be 4.3-12.6 for N. hexagonolepis and 4.1-10.3 for T. putitora. The ecotone zone was found to have a thriving mahseer population and ecotones are believed to play a crucial role as a diverse food source for the fish. Conserving Bhalukpong as a designated ecotone site in the Jia Bhoroli River as a fish sanctuary can help to protect their populations. Further research that encompasses all aspects of ecology is recommended for the future.

Effect of stocking density on the survival and growth of tank-reared Deccan mahseer Tor khudree (Sykes, 1849)

Deccan mahseer, Tor khudree (Sykes, 1849) is the most popular mahseer species of the Western Ghats. However, informationon optimising stocking density for fingerling rearing is not available for T. khudree. A study was undertaken to evaluate theeffect of stocking density on the growth and survival of the blue-fin mahseer, Tor khudree in fry to fingerling rearing. Fishwere reared for 90 days at stocking densities of 15, 25, 35 and 45 fish m-2 in soil-based 24 m2 masonry tanks. The tanks werefertilised initially with cow dung at 3 t ha-1 and were stocked with fry of T. khudree (mean length 1.31±0.09 cm; weight9.49±0.12 mg) after a week of manuring. A mixture (1:1) of powdered groundnut oil cake and rice bran was fed at 10% ofbody weight to the fish during the first month. Subsequently, fish were fed to satiation with a fishmeal-based sinking pelletedfeed (3 mm, 35% crude protein). The length of fish at harvest ranged from 5.03 to 6.43 cm and weight from 1.39 to 3.47 g.The mean final length, weight, specific growth rate and condition factor were the highest (p<0.05) under 15 m-2 and lowestunder 45 m-2 stocking density. The condition factor remained above 1 under all the treatments. No significant (p>0.05)difference in the survival of fish at harvest was recorded. Fish biomass estimates were higher (p<0.05) at higher stockingdensities. The similar (p>0.05) final length and condition factor between the stocking densities of 15, 25 and 35 m-2 and thehighest fish biomass at 35 m-2 indicate a stocking density of 35 fry m-2 as optimal for fry to fingerling rearing of T. khudree. Keywords: Blue-fin mahseer, Peninsular carp, Seed rearing, Stocking density

Conservation of mahseer fish in Madhya Pradesh by following M.I.R.A.C.L.E strategy

The endangered Mahseer species, especially Tor tor (Ham) is a state fish of Madhya Pradesh province of India. Ongoing construction of dams on the state’s rivers destroys the breeding and habitat ground of this fish species. To inspect the current situation, the conservation of Mahseer is commencing a big challenge for bio- diversity developers. To conserve the fish from steady deterioration, a unique M.I.R.A.C.L.E strategy has been endorsed which includes mapping of habitat, involving people with this project, research and data collection, advocacy for policy and legal framework, conservation measures following the restoration of the wild species through ex-situ & in-situ conservation, livelihoods connections, extension and training of frontline foresters on this conservation issue. In the future, this M.I.R.A.C.L.E strategy could help to guide in the right way to protecting this valuable fish species from being extinct. Nowadays Tor tor is famous as a Madhya Prad-esh state fish & river in the forested zone is the last hope for mahseer conservation

Conservation of Mahseer Fish in Madhya Pradesh by following M.I.R.A.C.L.E strategy

The endangered Mahseer species, especially Tor tor (Ham) is a state fish of Madhya Pradesh province of India. Ongoing construction of dams on the state’s rivers destroys the breeding and habitat ground of this fish species. To inspect the current situation, the conservation of Mahseer is commencing a big challenge for biodiversity developers. To conserve the fish from steady deterioration, a unique M.I.R.A.C.L.E strategy has been endorsed which includes mapping of habitat, involving people with this project, research and data collection, advocacy for policy and legal framework, conservation measures following the restoration of the wild species through ex-situ & in-situ conservation, livelihoods connections, extension and training of frontline foresters on this conservation issue. In the future, this M.I.R.A.C.L.E strategy could help to guide in the right way to protecting this valuable fish species from being extinct.

Potential impacts of non‐native fish on the threatened mahseer (Tor) species of the Indian Himalayan biodiversity hot spot

Abstract Mahseer (Tor) fish species are critical components of locally adapted freshwater food webs across the Indian Himalayan biodiversity hotspot; however, multiple human stressors compounded by climate change have significantly depleted their populations over recent decades. Mahseer species are now considered locally vulnerable or endangered in many regions. Hydropower projects in particular have fragmented populations, impairing genetic exchange, obstructing migratory paths, and changing the structure and functioning of riverine habitats, especially of formerly fast‐flowing rivers. Worryingly, a literature survey and group discussions reveal that the increasing spread of non‐native fish species further compounds threats to mahseer and overall freshwater ecology. A better understanding of the current distribution, habitat requirement, and dispersal of non‐native fish is therefore essential to manage the growing threats to mahseer in the Indian Himalayan region.

Morphological Operation Method for Eggs Identification in Gonad Ultrasound Image for Mahseer’s Fish (Tor Tombroides)

This paper describes an approach based on morphological operation for identifying the eggs in Mahseer’s gonad ultrasound image. In the context of breeding and seed production of Mahseer species, understanding and control of the Mahseer gonad maturation level have given strong interest for scientific and commercial purposes. From the studies, this Mahseer’s fish have different stage and size of eggs at the same time. Therefore, to identify the eggs in the gonad ultrasound image, an appropriate method is required. Morphological operation dilation and erosion with the structuring element shape is applied in this paper. In between these two operators, morphological reconstruction that includes filling the hole and clearing the border are also applied to the image. This method is essential for eliminating the egg sac because only the eggs region in the gonad will be processed. The proposed method also have been compared with the other research paper method. The result shows that the proposed method effectively identify the eggs in the gonad ultrasound image compared with the other research paper method. To our knowledge, this is the first report on the use of the morphological operation method in the gonad ultrasound image of Mahseer’s fish.

Complete mitogenome analysis of endangered Malabar mahseer (Tor malabaricus)

The complete mitochondrial genome of the endangered fish Tor malabaricus, (Malabar mahseer) was sequenced for the first time. The mitochondrial genome size was determined to be 16580 bp in length, consisting of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNA genes and a control region (D-loop). The overall base composition was A: 31.88%, T: 24.87%, G: 15.68% and C: 27.58%. The phylogenetic analysis of 13 protein-coding genes of available mitogenome of mahseer species showed that the T. malabaricus had closer relationship to the black mahseer T. khudree. The complete mitochondrial genome sequence of T. malabaricus would contribute to the better understanding of molecular systematics, selection, conservation, species identification and evolution of this species.

Gonad Ultrasonography Image Preprocessing for Mahseer (Tor Tombroides)

In the context of breeding and seed production of Mahseer species, understanding and control of the Mahseer gonad maturation level have given strong interest for scientific and commercial purposes. Possible use of ultrasonography for monitoring of gonad maturation in Mahseer fish is investigated. From previous studies, ultrasonography image of gonad can be affected by many speckle noise. Subtle differences between speckle noise and the Mahseer eggs lead to difficulties in identifying the eggs in ultrasonography gonad’s image. To eliminate these speckle noise, preprocessing image method is required. Filtering despeckling techniques is initially applied to remove the noise. There will be experimenting in comparing which despeckling technique is suitable for the gonad’s ultrasonography image. From the result, the best despeckling technique will be chosen and a framework of preprocessing method will be introduced for identifying the eggs in the gonad ultrasonography image. This noninvasive tool can then obviously be utilized to improve and monitor the maturation level of Mahseer fish. Ultrasonography thus has great potential for use in Mahseer fish both for conservation and aquaculture field. To our knowledge, this is the first article on the preprocessing of ultrasonography image on Mahseer or any fish species.

Terrestrial protected areas and managed reaches conserve threatened freshwater fish in Uttarakhand, India

Terrestrial protected areas and river reaches managed by local stakeholders can act as management tools for biodiversity conservation. These areas have the potential to safeguard fish species from stressors such as over-fishing, habitat degradation and fragmentation, and pollution. To test this idea, we conducted an evaluation of the potential for managed and unmanaged river reaches, to conserve threatened freshwater fish species. The evaluation involved sampling fish diversity at 62 sites in major rivers in Uttarakhand, India (Kosi, Ramganga and Khoh rivers) both within protected (i.e. sites within Corbett and Rajaji Tiger Reserves and within managed reaches), and unprotected areas (i.e. sites outside tiger reserves and outside managed reaches). In total, 35 fish species were collected from all sites, including two mahseer (Tor) species. Protected areas had larger individual fish when compared to individuals collected outside of protected areas. Among all sites, lower levels of habitat degradation were found inside protected areas. Non -protected sites showed higher impacts to water quality (mean threat score: 4.3/5.0), illegal fishing (4.3/5.0), diversion of water flows (4.5/5.0), clearing of riparian vegetation (3.8/5.0), and sand and boulder mining (4.0/5.0) than in protected sites. This study supports the importance of existing terrestrial protected areas and managed sites for conserving threatened fish and preventing harmful activities.

Eff icacy of angler catch data as a population and conservation monitoring tool for the f lagship Mahseer f ishes (Tor spp.) of Southern India

Abstract Mahseer (Tor spp.) are flagship fishes in South Asian rivers. Their populations are threatened through poaching and habitat disturbance, yet they are highly prized game fishes due to their large size, appearance and sporting qualities. The international recreational angling community has frequently been cited as playing a vital role in conserving these fishes while also providing economic benefit to poor rural communities. Owing to a lack of scientific data and the considerable challenges associated with monitoring fish populations in large monsoonal rivers, efforts to determine the long‐term trends in their populations has focused on sport‐fishing catch records. Here, catch data collected between 1998 and 2012 from Galibore, a former fishing camp on the River Cauvery, Karnataka, India, were analysed to determine the catch per unit effort (CPUE – by number and weight) as an indicator of relative fish abundance, along with the size structure of catches. This fishery operated a mandatory catch‐and‐release (C&R) policy, and provided the fish community with protection from illegal fishing. Between 1998 and 2012, 23 620 hours fishing effort were applied to catch and release 6161 mahseer, ranging in size from 1 to 104 lbs (0.45–46.8 kg) in weight. Across the period, CPUE in number increased significantly over time with a concomitant decrease in CPUE by weight, revealing strong recruitment in the population and a shift in population size structure. This suggests a strong response to the C&R policy and the reduction in illegal fishing, indicating that conservation strategies focusing on the beneficial and negative aspects of exploitation can be successful in achieving positive outcomes. These outputs from angler catch data provide insights into the mahseer population that were impossible to collect by any alternative method. They provide the most comprehensive analysis of a long‐term dataset specific to any of the mahseer species across their entire geographical range and demonstrate the value of organised angling as a conservation monitoring tool to enhance biological data, and inform conservation and fishery management actions. Copyright © 2014 John Wiley & Sons, Ltd.

Molecular evidence to reconcile taxonomic instability in mahseer species (Pisces: Cyprinidae) of India

The mahseers are an important group of fishes endemic to Asia with most species considered threatened. Conservation plans to save declining wild populations are hindered by unstable taxonomy, and detailed systematic review could form a solid platform for future management and conservation. D-loop and cytochrome c oxidase I (COI) mtDNA sequences were examined in nine mahseer species of Tor, Neolissochilus, and Naziritor. Pseudogenes amplified in a portion of the species limited the utility of the D-loop region. ABGD analysis, NJ, ML, and MP methods and genetic distance (TrN + I + G) using COI data revealed concordant species delimiting patterns. The three genera were monophyletic, separated as distinct clades (TrN + I + G 0.064 to 0.106), and Naziritor was flagged as a separate genus, distinct from Puntius (TrN + I + G 0.196). Out of seven nominal species known for Tor cogeners from India, only five were recovered with mtDNA data (TrN + I + G 0.000 to 0.037) and two species could not be distinguished with the molecular data set employed. Tor mosal, synonymized as Tor putitora, was rediscovered as a distinct species (TrN + I + G 0.031) based on its type locality. Tor mussulah was confirmed as a separate species (TrN + I + G 0.019 to 0.026). Two valid species, Tor macrolepis and T. mosal mahanadicus, were not distinct from T. putitora (TrN + I + G 0.00). The high divergence with mtDNA data failed to validate T. mosal mahanadicus as a subspecies of T. mosal (TrN + I + G 0.031). Morphological outliers discovered within the distribution range of Tor tor (TrN + I + G 0.022 to 0.025) shared the same lineage with T. putitora (TrN + I + G 0.002 to 0.005), indicating a new extended distribution of the Himalayan mahseer T. putitora in the rivers of the Indian central plateau. The findings indicate the need for integrating molecular and morphological tools for taxonomic revision of the Tor and Naziritor genera, so that taxa are precisely defined for accurate in situ and ex situ conservation decisions.

Review of the Art and Science of Indian Mahseer (Game Fish) from Nineteenth to Twentieth Century: Road to Extinction or Conservation?

Mahseer species, the national heritage of India are globally acclaimed sport and table fish. Some mahseer species are now assessed as ‘endangered’, making it imperative to review historical and current state of knowledge on sport-related facets, taxonomy, fisheries ecology, biology, culture and conservation efforts. The review also examines the shortfalls in knowledge base and suggests issues that need to be addressed in future. The protection and conservation measures have fallen short of expectations as the pace of implementing mega-developmental projects exceeds natural recruitment rate of mahseers and lack of facilities for assisted propagation, at larger scale.

Molecular characterization of major and minor rDNA repeats and genetic variability assessment in different species of mahseer found in North India

Relationship among the mahseer species (Family: Cyprinidae) has long been debated in fish systematics. Present study concentrates on the nature of the phylogenetic relationship among the five mahseer species using the sequence of major ribosomal DNA (45S rDNA). We have covered rDNA sequence of approximately 5.2kb per individual, 26.0kb per species and 130.0kb as a whole. We also characterized the 45S and 5S rDNA regions with respect to their nucleotide composition. For phylogenetic analyses, nucleotide sequences were divided into four datasets. First and second datasets contained 18S rDNA and ITS1 sequence, whereas third and fourth datasets consisted of ITS2 and complete 18S-ITS1-5.8S-ITS2-28S, respectively. The NJ tree was constructed for all the datasets. The mahseer species under study formed a monophyletic group well separated from the outgroup species. Similarly, the individuals of Neolissochilus hexagonolepis form monophyletic group with Tor species, indicating Neolissochilus as a sister genus of Tor. The findings from the present study provide greater insights into taxonomic status of mahseer, and set the stage for future investigations dealing with phylo-geography, taxonomy, conservation and co-evolution within this interesting and important group of fish.

The Species Dilemma of Northeast Indian Mahseer (Actinopterygii: Cyprinidae): DNA Barcoding in Clarifying the Riddle

BackgroundThe taxonomic validity of Northeast Indian endemic Mahseer species, Tor progeneius and Neolissochilus hexastichus, has been argued repeatedly. This is mainly due to disagreements in recognizing the species based on morphological characters. Consequently, both the species have been concealed for many decades. DNA barcoding has become a promising and an independent technique for accurate species level identification. Therefore, utilization of such technique in association with the traditional morphotaxonomic description can resolve the species dilemma of this important group of sport fishes.Methodology/Principal FindingsAltogether, 28 mahseer specimens including paratypes were studied from different locations in Northeast India, and 24 morphometric characters were measured invariably. The Principal Component Analysis with morphometric data revealed five distinct groups of sample that were taxonomically categorized into 4 species, viz., Tor putitora, T. progeneius, Neolissochilus hexagonolepis and N. hexastichus. Analysis with a dataset of 76 DNA barcode sequences of different mahseer species exhibited that the queries of T. putitora and N. hexagonolepis clustered cohesively with the respective conspecific database sequences maintaining 0.8% maximum K2P divergence. The closest congeneric divergence was 3 times higher than the mean conspecific divergence and was considered as barcode gap. The maximum divergence among the samples of T. progeneius and T. putitora was 0.8% that was much below the barcode gap, indicating them being synonymous. The query sequences of N. hexastichus invariably formed a discrete and a congeneric clade with the database sequences and maintained the interspecific divergence that supported its distinct species status. Notably, N. hexastichus was encountered in a single site and seemed to be under threat.ConclusionThis study substantiated the identification of N. hexastichus to be a true species, and tentatively regarded T. progeneius to be a synonym of T. putitora. It would guide the conservationists to initiate priority conservation of N. hexastichus and T. putitora.

Population dynamics and conservation management of Himalayan mahseer (Tor species) in riverine aquatic ecosystem in Garhwal region of Uttarakhand (India)

The mahseer, an Indian carp (Tor species) known as ‘Sport fish’ continues to be decimated by the large scale natural and anthropogenic factors and categorized as threatened fishes in India. The present research data revealed that total species richness of 33 and 24 number of fish species were identified in river Ganga and Yamuna respectively. The size group of mahseer (400-460mm) recorded as a dominant size of catch composition and contributed about 36.8% and 42.6% based on different sampling sites in river Yamuna and Ganga respectively. The populations of Tor tor, T. putitora have shown a decreasing trend at very alarming rate and influenced the sex ratio, maturity size and natural breeding condition. Only 12.5 to 14.8% mahseer female brooders have shown maturity phase or emenable to release ova during particular breeding seasons. The fecundity of mature female fish brooders ranged from 2500-4500 no. of eggs during July-August. The current status of mahseer fishery may be attributed to the over exploitative nature in riverine system. ‘In situ and Ex-situ” breeding techniques should be practiced for enhancement of viable population size of mahseer species to restore the genetic loss under mahseer conservation programme in aquatic ecosystem of Himalayan region.

Cytogenetic characterization of an endemic mahseer, Tor mosal mahanadicus (David, 1953; Teleostei : Cyprinidae)

The Tor mosal mahanadicus (David, 1953) is an endangered mahseer species well known for its high food value. The taxonomy of the species is confusing owing to the morphological variations and the habitat adaptations. These taxonomic ambiguities need to be resolved for development of strategies for their rehabilitation and use in aquaculture. The cytogenetic markers have been considered as authentic and robust tools to resolve taxonomic ambiguity among the groups of fishes. The cytogenetic characteristics were investigated in T. mosal mahanadicus using karyotyping, Ag-NOR and fluorescence (CMA3) staining techniques. The basic diploid chromosome number (2n) was observed to be 100 and the karyotype formula and fundamental arm number (FN) were derived as 22m + 12sm + 22st + 44t and 134, respectively. Silver and CMA3 staining of the metaphase chromosomes revealed presence of multiple nucleolar organizer regions (3 pairs). The information on cytogenetic study of this mahseer species has been discussed in the light of cytotaxonomic implications.

Karyotypic diversity and evolution of seven mahseer species (Cyprinidae) from India

Mahseer is a group of fish species that are well known as food and game fishes. The taxonomy of the mahseer species is confusing owing to the morphological variations and habitat adaptation. Detailed karyomorphological investigations have been carried out in seven species of mahseer, using karyotyping, Ag-NOR and fluorescent staining techniques. The basic diploid chromosome number (2n), in all mahseer species, was observed to be 100; however, the karyotype formula varied among the species, which were recorded as: 20m + 14sm + 22st + 44t (fundamental arm number, FN = 134) in Tor khudree; 22m + 24sm + 24st + 30t (FN = 146) in Tor mussullah; 12m + 22sm + 14st + 52t (FN = 134) in Tor putitora; 20m + 24sm + 24st + 32t (FN = 144) in Tor tor; 20m + 30sm + 24st + 26t (FN = 150) in Tor chelynoides; 20m + 20sm + 20st + 40t (FN = 140) in Tor progeneius; and 20m + 18sm + 14st + 48t (FN = 138) in Neolissochilus hexagonolepis. Silver staining of the chromosomes revealed the presence of multiple nucleolar organizer regions (NOR) in these mahseer species. The highest number of NORs was observed in T. tor (four pairs of chromosomes), whereas the other six species possessed Ag-NOR signals on only two pairs of chromosomes. Although chromomycin A(3) (CMA(3)) staining induced bright fluorescence signals on same Ag-NORs sites, with CMA(3), one additional signal was observed on the p arm of subtelocentric chromosomes in T. tor, T. chelynoides, T. progeneius and N. hexagonolepis, which may indicate the presence of inactive NOR in these species. The information on cytogenetic profile of these mahseer species is discussed in the light of cytotaxonomic implications and understanding the karyoevolution of these fish species.

Use and exchange of genetic resources of emerging species for aquaculture and other purposes

AbstractFrom a genetic resources viewpoint, emerging aquaculture species and species groups are examined mainly in terms of food use. In addition, we include species that are becoming increasingly important for biodiversity conservation and related ecotourism aspects. Together with ornamental fish species, we argue that these species are facing increasing vulnerability and warrant attention. Our intention is to raise awareness of the potential for increasing production and revenues from emerging species/species groups with an emphasis on an underlying link to biodiversity conservation and ecosystem preservation, and how this information will inform policy on access to the genetic resources and the sharing of benefits derived from their use. For food purposes, the fastest growing aquaculture sector is mariculture, and within this sector groupers and wrasses are considered to be the most important because they cater to the relatively lucrative live food fish restaurant trade (LFFRT), which is rapidly expanding in selected South‐East Asian countries. In the Asian region, ecotourism is an emerging sector and a prominent fish group for this purpose is considered to be mahseer. A number of mahseer species are culturally and commercially important and are often seen as a group of indigenous species that are suitable for aquaculture. This review summarizes much of the limited information related to the patterns of use and exchange of genetic resources on emerging aquatic species/species groups, with particular reference to Asia.