Tor Tambra Research Articles

The Effect Of Stocking Densities On Growth And Survival Rate Of Thai Mahseer (Tor Tambroides) During Nursery Stage.

Abstract Tor Fish are freshwater fisheries resources that have the potential to be found in Indonesia. Tor fish has been in high demand among entrepreneurs and the broader public. Tor tambroides (Sapan fish or Thai mahseer fish seed fish), Tor douronensis (Semah or Garing fish), Tor soro (Soro, Lempon, or Dewa fish), and Tor tambra are the four kinds of Tor fish native to Indonesia. Tor fish is a native indigenous freshwater fish from Indonesia that is on the verge of extinction. The Tor tambroides fish population in nature has declined and is on the verge of extinction as a result of widespread poaching for eating and trade as an ornamental fish. Thai mahseer fish seed fish cultivation activities include hatchery, nursery and enlargement. To protect populations of Thai mahseer fish seed fish from scarcity, Thai mahseer fish seed fish cultivation needs to do to prevent the scarcity of Thai mahseer fish seed fish in their natural habitat and Thai mahseer fish seed fish have high potential as freshwater fish in the aquaculture sector. This research aims to determine the impact of various stocking densities on growth and survival rates for Thai mahseer fish seeds, as well as the optimal density to support growth and survival rates. The study used a Random Design Complete (RDC) with four treatments and five replications. Feeding was provided ad libitum in the morning and evening. Given differences in the stocking density of Thai mahseer fish seeds, the results revealed a significant impact on all treatments. Treatment 1 had the greatest daily growth rate with a stocking density of 2 seeds/L and a yield of 0.015±0.003; specific growth rate. The highest absolute weight growth obtained was in Treatment 1 with a yield of 1.01gr; the highest absolute length growth obtained was in Treatment 1 with a yield of 2.9cm; and the highest survival rate for Thai mahseer fish seeds was obtained in Treatment 1 with a yield of 80%.

Growth patterns and ecological classification of Tor tambra (Valenciennes 1842) in the Mamis River, Leuser Ecosystem Area, Aceh Province, Indonesia

Graphical Abstract Highlight Research 1. Tor tambra is the most dominant species other Tor species in Aceh Province, Indonesia. 2. The population of T. tambra has decreased significantly due to overfishing and environmental destruction. 3. This research aims to examine the habitat characteristics, growth patterns and condition factors of T. tambra. 4. Analysis of the length weight relationship of T. tambra revealed that the condition of the fish was stable . Abstract This research was aimed to examine the habitat characteristics, growth patterns and condition factors of T. tambra in the Mamis River, Leuser Ecosystem Area, Aceh, Indonesia. This research was conducted on the Mamis River in three different river conditions from July to August 2023. The ecological parameters of T. tambra were conducted by observing the main, broodstock, spawning, and nursery ground habitats based on diversity of catch size at a location, water quality, aquatic substrate, aquatic vegetation, and water shade. The growth pattern parameter was also analyzed to reveal the condition of T. tambra. The T. tambra habitat in the Mamis River includes broodstock and spawning habitat with the criteria from small to large rocks overgrown with Bryophytes, gravel and sand substrates, clear water color, slow to swift water currents, and river environment most of it is primary forest. In the main habitat, there is dominant riparian vegetation in the form of forest timber trees such as Pometia pinnata, Ficus fistulosa, Hydnocarpus castanea, and Aglaia tomentosa. The habitat for the juvenile is in the form of rocks, gravel substrate, clear water color, and fast water currents. In the nursery habitat, the dominant riparian vegetation is Balakata baccata. Based on the results of water quality analysis at the three stations, it shows that temperature, pH, DO, currents, BOD, COD are significantly different, but brightness levels are not significantly different. Based on the analysis of the length-weight relationship, it shows that the condition of the fish is stable with sufficient food availability.

Biometrics of the gastrointestinal tract of Tor tambra and Tor soro from Aceh, Indonesia

The gastrointestinal tract of native fish shows structural and functional diversity, which is related to different dietary requirements, feeding habits, phylogeny, age, body shape, and sex. There is some research that discusses the digestive tract of fish, but research on the digestive tract of Tor tambra and Tor soro is still limited. The purpose of this study was to describe the biometrics of the stomach and intestines of T. tambra and T. soro harvested from Leuser Ecosystem Area. This study included sample collection, sample preparation, gastrointestinal biometrics, and data analysis. The observation parameters include GaSI (Gastro Somatic Index), ISI (Intestine Somatic Index), RGL (Relative Gut Lengths), and RIL (Relative Intestine Lengths). The measurement data were tested using analysis of variance (ANOVA). The results showed that the highest GaSI, ISI, RGL and RIL values were in T. tambra with respective values of 0.50±0.24%, 2.46±0.58%, 44.35±5.22%, and 340.37±33.99%, while the lowest values were found in T. soro, whereas 0.22±0.07%, 1.57±0.55%, 32.03±14.99%, and 259.62±65.74%, respectively. The results of the statistical analysis showed that there were significant differences (P<0.05) in the GaSI, ISI, and RIL values, while RGL no significant differences (P>0.05) between the two species.

Comparative anatomical study of gill fish of Tor tambra, Tor soro, and Hampala macrolepidota as an environmental bioindicator

Gills are respiratory organs and bioindicators of environmental pollution since they are directly related to the environment. This study aims to examine anatomical differences in the gills of Tor tambra, Tor soro, and Hampala macrolepidota. This study used 5 fish with an average weight of 2-5 kg collected from the Tangse River area, Pidie Regency, Aceh and the Bahorok River area, Langkat Regency, North Sumatra. The research step comprised sampling, transportation, dissection, photo shooting and editing, morphological analysis and data analysis. Morphological studies were observed from the shape, location, and the number of each gill. Data were analyzed descriptively in the form of tables and figures. Results of morphological comparison showed that the fish’s gill apparatus consisted of arcus branchialis, filamen branchialis and branchiospinalis. In T. tambra and T. soro, the shape of the arcus branchialis resembled inverted L-like curve, compared to H. macrolepidota which resembled a crescent moon. Each filamen branchialis sheet of T. tambra was sparse, while T. Soro was denser and H. macrolepidota had shorter filament. T. tambra and T. soro had a sharp and dense branchiospinalis compared to H. macrolepidota which was pointed and sparse. The ceratobranchialis raker of H. macrolepidota fish was not developed compared to that of T. tambra and T. soro which were more developed.

Year-round spawning of three tropical Cypriniformes fishes in Southeast Asia

Present knowledge on spawning seasonality of freshwater fishes in tropical Asia and their relationship with environmental factors remains limited. Three Southeast Asian Cypriniformes fishes, Lobocheilos ovalis, Rasbora argyrotaenia and Tor Tambra, found in rainforest streams in Brunei Darussalam were studied on a monthly basis for a period of 2 years. To assess spawning characteristics, seasonality, gonadosomatic index and reproductive phases were examined from 621 L. ovalis, 507 R. argyrotaenia and 138 T. tambra. This study also examined environmental factors such as rainfall, air temperature, photoperiod and lunar illumination that may influence the timing of spawning of these species. We found that L. ovalis, R. argyrotaenia and T. tambra were reproductively active throughout the year but did not find that spawning in these species were associated with any of the investigated environmental factors. Our study showed that the non-seasonal reproductive ecology found in the tropical cypriniform species is distinctly different from that of temperate cypriniforms, which are known to follow spawning seasonality, suggesting an evolutionary adaptation to ensure their survival in an unstable environment. The reproductive strategy and ecological responses found in the tropical cypriniforms might be shifted in response to climate change scenarios in the future.

Total Suspended Solids (TSS) Adverse Effect Level to Malaysian Mahseer (Tor tambra)

Total Suspended Solids (TSS) Adverse Effect Level to Malaysian Mahseer (Tor tambra)

Food and feeding habits of Tor tambra (Valenciennes, 1842) in Cibareno River, West Java, Indonesia

The Cibareno River in Sukabumi, West Java, is the habitat of Tor tambra, one of Indonesia's most highly valuable native freshwater fish species. The native fish population in this river may be threatened by the planned weir construction. The study aims to examine the food and feeding habits of Tor tambra in the Cibareno River. This study was carried out for four months (May, June, July, and September 2022) at six locations in the Cibareno River. A total of 61 individuals of T. tambra displayed an isometric growth pattern with good condition factor. Aquatic insects were the primary food, with nematodes and phytoplankton acting as supplements. Plant seeds were often eaten as an extra source of food. These results were supported by fish morphometric data such as relative mouthwidth and relative gut length, which showed that they are omnivorous and tend to be carnivorous. In addition, the relative eye diameter of the fish indicates that Tor tambra is a diurnal forager. The findings suggest that both in-situ and ex-situ conservation methods are viable options for the preservation of Tor tambra in the Cibareno River.

Assessment of trial sport fishing commercialization in newly developed Hulu Terengganu Hydroelectric Station: A case study of Puah Reservoir, Terengganu, Malaysia

TNB Research (TNBR) was conducted a pilot study on the commercialization of catch and release sport fishing in Puah Reservoir, a new hydroelectric project within the Hulu Terengganu Hydroelectric Station (HTHS). The objective of this study is to evaluate the impact of the sport fishing programme on socio-economic benefit and its potential as a component of Non-Timber Forest Products (NTFPs). The evaluation was conducted in two phases, from November 2017 to May 2018 (Phase 1) and October 2018 to December 2019 (Phase 2), which covered the reservoir and its catchments, such as Terengganu Mati, Limbang, Pelagong, and Sireh rivers. The information was gathered from registered anglers who fished 12 days per month, using two boats with a maximum of two anglers per boat and casting methods from 0700 to 1630. The results show that November 2017 had the highest average of fish strikes per angler with a value of 11. This value was recorded as a standard for the best strikes at the Puah Reservoir. Every angler recorded an average of six fish strikes per month, with the exception of December and early January, which were closed due to the monsoon season. Based on the population of fish strikes, the Sebarau (Hampala macrolepidota) species had the highest catch for both phases, accounting for 71% and 73% of all strikes, respectively. Haruan (Channa striata), Bujuk (Channa lucius), Tengas (Neolissochilus soroides), Baung (Hemibagrus capitulum), Tengas Daun (Poropuntius normani), and Kelah (Tor tambra) were also observed. Based on the net income, the revenue had increased, indicating an increase in demand and willingness to pay from anglers. The monthly income (on a part-time basis) was determined by the number of anglers who registered for the Sport Fishing programme. The In-House Guide earned a total net income of RM35,560.00 or USD8114.09 (Phase 1) and RM41,640.00 or USD9501.43 (Phase 2). As a baseline study, all income was collected by the cooperation run by the local community. To summarise, sport fishing at Puah Reservoir supports NTFPs, which can serve as forest conservation, a sustainable environment, and a new source of income for the local community if proper management practices are implemented.

Efficacy of Black Soldier Fly (Hermetia illucens) Larvae Meal as Feed on Growth Performance for Juvenile Javan Mahseer (Tor tambra)

Fish meal (FM) is a well known protein source for fish feed and its heavy utilization has contributed to overfishing that lead to increase price of formulated feed due to scarcity of fish resources for fish meal. Several studies were done to identify the best substitution of FM including Black Soldier Fly (Hermetia illucens) larvae as a potential candidate for FM replacement. This study was done to investigate the proximate composition of Black Soldier Fly Larvae Meal (BSFLM) and to determine its efficacy as feed on growth performance of Javan Mahseer (Tor tambra). Three types of treatment were used namely F0 or control (0% BSFLM and 100% FM), F50 (50% BSFLM and 50% FM) and F100 (100% BSFLM and 0% FM). Each treatment was fed twice daily for 20 days to 10 Javan Mahseer with the average initial weight of 0.1g respectively. Analyses conducted was proximate composition and growth performance like specific growth rate, feed conversion ratio, survival rate and body weight gain. Data was analysed using One-way Analysis of Variance (ANOVA) SPSS Windows 27. Results show that crude protein in F0, F50 and F100 were 37.52%, 30.36% and 27.52%; while F50 indicated best BWG (66.71%) and lowest FCR (3.16) respectively. It can be concluded that treatment 50% inclusion of BSF is the best ratio for good growth performances of Javan Mahseer.

Application of Different Temperatures in the Incubation Process of Jurung Fish Eggs (Tor tambra)

The habitat of the Jurung Fish (Tor tambra) is generally inflowing rivers, rocky bottom waters and relatively low water temperatures. This study aimed to determine the hatchability of the Jurung Fish (Tor tambra) eggs with different temperature treatments using a tray in the aquarium. The research method used is the laboratory experimental method and the experimental design is a non-factorial completely randomized design (CRD) consisting of 4 treatments and 4 replications: A (control), B (28°C), C (30°C) and D (32°C). The results showed that the application of different temperatures had a significant effect on the hatching of the Jurung Fish (Tor tambra) eggs. The results of Duncan's further test analysis showed that the 28°C temperature treatment was the best compared to other temperatures. This study recommends that further research is needed on larval abnormalities at different water temperatures.

Molecular characterization of genus Tor from Indonesia based on 16S rRNA

Genus Tor is Indonesia's endangered local fish however, the reports on this species from South East Asia is currently limited. This study conducted to characterize molecular genetics and phylogenetic relationship of Tor fish from East Java, West Kalimantan, Padang and North Sumatra from BPBAT Bogor collection using a partial sequence of mtDNA 16S rRNA. A total of ten samples of Genus Tor were collected, then identified based on morphological characters, and the identification was confirmed using molecular data. PCR amplicons at 542 bp in length. The construction of phylogenetic topology was made based on ML and NJ method using Kimura-2 parameter model. Based on the phylogenetic topology showed that Tor fish from Pasuruan are closely related to Tor duoronensis from Padang with a bootstrap value of 66%, while Tor duoronensis fish from North Sumatra and Tor tambra from West Kalimantan are in separated clusters. This finding also contributes to the differentiate Genus Tor from Indonesia based on polymorphic sites.

Fish Biodiversity and Water Quality of Tropical Forest Streams Adjacent to the Western Boundary of Kinabalu Park, Sabah

Modification and degradation of habitats outside the boundaries of a national parkmay result in the park's integrity being compromised. Thus, the present study aims todocument variation in freshwater fish and water quality of tropical forest streams adjacent to the western boundary of Kinabalu Park, Sabah. Concurrently, fish samplesand environmental parameters were collected at six stations covering a total streamline length of 10 km. The three most abundant species were Tor tambra (34.4%), Barbodes sealei (19.5%), and Lobocheilos ovalis (12.4%). Tor tambra exhibited a negative allometric growth pattern (coefficient < 3) and was in poor to fair condition (0.8< Fulton’s condition factor < 1.2). The highest fish abundance was found in downstream stations with species addition. Metrics of diversity, such as Shannon's diversityindex and the Margalef index of species richness, decreased as elevation increasedfrom 100 to 600 metres above sea level. The water quality of the forest streams isgood, classified as Class I and/or Class II by Malaysia's National Water Quality Standards, except for ammoniacal nitrogen at station 6, which was classified as Class III.Higher turbidity, orthophosphate, and ammoniacal-nitrogen values were found nearthe Podos village. In conclusion, the altitudinal gradient of fish biodiversity was observed in the forest streams near Kinabalu Park. Regular water quality monitoring ofthe downstream river is necessary, as indicated by the potential domestic impacts onthe river.Keywords: Biodiversity, Elevation, Freshwater fish, Forest stream, Kinabalu Park

Mahseer, the history of the king of the river

Mahseers (Cyprinidae) is one of the most important freshwater fish in Southeast Asia. This fish is being a consumption fish, ornamental and sport fishing. Mahseers can grow up to more than 30 kg. Therefore, this species is called The King of The River. This paper reviewed some aspects of this interesting fish. A total of 54 papers have been reviewed where some of the papers come from our Ichthyos Research Group, Universitas Syiah Kuala. There are 50 species of mahseer throughout the world, where 20 species of which are found in Asia. Indonesia has four species of mahseer, namely; Tor tambra, T. tambroides, T. duorenensis, and T. soro, of which two species, T. tambra and T. tambroides are found in Aceh province. Between the two species, T. tambra has a wide distribution. The original habitat of the mahseer fish waters with speed currents, clear water, high dissolved oxygen, and low water temperatures. In the wild, mahseers migrate upstream for spawning during periods of high flooding in the early rainy season. The spawning occurs one or two months at the place that is inundated during floods. Mahseer is omnivorous, they fed on mollusks, aquatic plants, small fish, insects to fruits that grow on the banks of rivers. Mahseer fish in rearing ponds are often attacked by Lernea sp., Argulus sp., Trichodina sp., and Bothriocephalus acheilognathi worms

The first de novo genome assembly and sex marker identification of Pluang Chomphu fish (Tor tambra) from Southern Thailand

The Tor genus belongs to the group of cyprinid fish commonly known as mahseer. Although Tor species are rapidly declining in the wild, and some face extinction, ambiguities in species identification hinder their collection and conservation. We conducted a genome survey of male and female Tor tambra collected in Thailand. The genome sizes of the male and female fish were approximately 1,671 and 1,645 Mb, respectively, with repeat contents of approximately 33%. The heterozygosity ratios of the male and female fish, which were 0.34% and 0.39%, respectively, suggested that the sex of T. tambra is determined by the ZW system. A sex marker was identified in silico and confirmed by PCR amplification. The result indicated that T. tambra has a ZZ/ZW sex determination system. Subsequently, comparative genomic and phylogenetic analyses of T. tambra and other fish in the Cyprinidae family were performed to explore the genetic diversity and evolution of the species. We also assembled the complete mitochondrial genome sequences of the T. tambra collected in Thailand. A phylogenetic tree of different Tor species, constructed based on mitochondrial genome sequences, indicated that T. tambra was closely related to T. tambroides. We believe this is the first genome survey of a species from the Tor genus or Mahseer group. Our results may help identify Tor species, providing a reference for genetic studies of the Tor genus and other mahseer fish.

Survey of Freshwater Fish in Kadamaian Area, Western Sabah

The freshwater fish fauna was surveyed in forest streams located in the Kadamaian area, Sabah during the Borneo Geographic Expedition 2019. Fish samples were obtained from six stations by electrofishing from an upstream to downstream direction. A total of four families, 12 genera, and 14 species of fish were recorded from the present study. The most dominant family was Cyprinidae (10 species; 71.43%), followed by Gastromyzontidae (2 species; 14.29%), Nemacheilidae (1 species; 7.14%), and Mastacembelidae (1 species; 7.14%). The number of species was low in upstream stations at higher altitude but substantially higher in downstream stations with lower altitude. Economically valuable fish, Tor tambra was found at all stations. Gastromyzon monticola which is endemic to Sabah was also recorded at most stations.

Microsatellite Characterization of Malaysian Mahseer (Tor spp.) for Improvement of Broodstock Management and Utilization

Simple SummaryThe Malaysian mahseer (Tor ssp.) of the family Cyprinidae are indigenous large riverine cyprinids that occur only in Southeast Asia. They are the popular freshwater fish for food, ornamental and recreational fishing. However, their wild populations are now ecologically threatened as their numbers decline drastically over the years due to over-exploitation, natural habitat degradation and water pollution. With successful hatchery production, readily accepted artificial feed and fetched high market value, Malaysian mahseer is now considered a perspective for aquaculture. Stocks were collected from various sources for broodstock development to establish an appropriate base population with desirable characteristics that harbour adequate genetic diversity. Information on the genetic status is essential to formulate appropriate strategies for genetic resources protection and its utilization. Genetic diversity of the broodfish can be assessed rapidly with high precision using polymerase chain reaction (PCR)-based DNA markers.In this study, a mixture of Tor tambra and T. tambroides with unknown genetic background were collected from 11 localities in Malaysia for broodstock development and sperm cryo-banking. This study aims to assess the microsatellite (simple sequence repeat, SSR) variation, genetic diversity, genetic differentiation, level of gene flow, population structure, genetic relatedness and their demographic aspects among these Tor populations, in addition to establishing their SSR profile by employing 22 SSR markers via fragment analysis. Total genomic DNA was extracted from 181 samples (91 cryopreserved milt samples and 90 scale samples of live broodfish). Results showed the Tor spp. collection retained their genetic variation but exhibited excessive homozygosity among individuals within population. Moderate genetic differentiation was shown among the populations, with highly significant (p < 0.001) fixation indices (FST, FIS and FIT). A low gene flow over all loci (Nm 1.548) indicates little genetic variation transfer between populations. The genetic structures of all the populations were successfully resolved into four main clusters by an unweighted pair group method with arithmetic mean (UPGMA) dendrogram generated based on Nei’s genetic distances. The population structures based on principal coordinates analysis (PCoA) and the Bayesian model also suggested four distinct clusters following geographical regions and eight closely related populations. This study provided a useful baseline reference for better genetic management and utilization of the Tor spp. stocks in their breeding and conservation programmes.

Fish biodiversity and assemblages along the altitudinal gradients of tropical mountainous forest streams

Knowledge of the fundamental aspects of ecology such as the patterns of fish species distribution and biodiversity in the forest streams is the first and basic step to develop effective conservation strategies. Yet, studies on altitudinal changes of fish composition and assemblages in Bornean forest streams are scarce despite being one of the hotspots of biodiversity conservation. Hence, surveys on freshwater fish composition along the altitudinal gradients of the Baleh River Basin in Sarawak, Borneo were conducted from April 2014 to August 2015. The Baleh River Basin was divided into seven altitudinal groups with a total of 72 stations. Group elevation ranged from 53 to 269 m above sea level. The fish samples and environmental parameters were taken concurrently during samplings. A total of 3565 specimens belonging to six orders, 14 families, and 76 species were found in the present study. The most dominant family in the Baleh River Basin was Cyprinidae (74.4%), followed by Gastromyzontidae (16.2%) while the most dominant species was Tor tambra (12.9%), followed by Lobocheilos ovalis (12.3%). Fish abundance significantly higher at high altitude sites than those at low altitude sites except for Mengiong River which has the lowest fish abundance despite with high elevation. Species richness was found significantly lower in midstream segment. Noticeable altitudinal gradient of fish assemblages was observed along the Baleh River except a discontinuity at the midstream segment which is attributable to the poorer quality inflow from the Mengiong River coupled with the meandering feature of the segment. Fish abundance was significantly and positively correlated with elevation, water pH and conductivity while negatively correlated with turbidity. Anthropogenic activities in the Baleh River Basin had altered the environmental variables thus disrupted the altitudinal gradient of fish assemblages. This phenomenon is apparent when the Canonical Correspondence Analysis (CCA) revealed that the first axis (CCA1) explained 42.5% of the variation and has positive loading on dissolved oxygen (DO) and negative loading on water conductivity; whereas CCA2 explained 37.5% of the variation and positively loaded on elevation, water pH, and DO. The results demonstrated that Gastromyzon fasciatus preferred more oxygenated water than Protomyzon sp., G. sp 1, and G. punctulatus although they are all from Gastromyzontidae family that inhabiting high altitude sites. Barbonymus schwanenfeldii was also found most abundant with elevated dissolved oxygen value. On the other hand, Rasbora volzii and R. hosii inhabiting lower altitude sites with less oxygenated and more acidic water.

Population of Tambra Fish (Tor tambra) in Batang Gadis River Mandailing Natal North Sumatra

Tambra Fish (Tor tambra) is a commodity of freshwater fish with a high economic rate, therefore the community takes tambra fish continuously. The cultivation of tambra fish from Batang Gadis river Mandailing Natal has not been done, this research aims to find out the population of tambra fish and physical-chemical factors in Batang Gadis river. This type of research is descriptive. The location of the study was determined using purposive random sampling at every 4 (four) stations. The results showed that the population of Tor tambra in Batang Gadis river Mandailing Natal is classified as medium with the population structure is mostly the size of a small fish. The condition of the habitat of tambra fish in Batang Gadis river Mandailing Natal in general is still good enough for the life of tambra fish.

Improving the phylogenetic resolution of Malaysian and Javan mahseer (Cyprinidae), Tor tambroides and Tor tambra: Whole mitogenomes sequencing, phylogeny and potential mitogenome markers.

The true mahseer (Tor spp.) is one of the highest valued fish in the world due to its high nutritional value and great unique taste. Nevertheless, its morphological characterization and single mitochondrial gene phylogeny in the past had yet to resolve the ambiguity in its taxonomical classification. In this study, we sequenced and assembled 11 complete mahseer mitogenomes collected from Java of Indonesia, Pahang and Terengganu of Peninsular Malaysia as well as Sarawak of East Malaysia. The mitogenome evolutionary relationships among closely related Tor spp. samples were investigated based on maximum likelihood phylogenetic tree construction. Compared to the commonly used COX1 gene fragment, the complete COX1, Cytb, ND2, ND4 and ND5 genes appear to be better phylogenetic markers for genetic differentiation at the population level. In addition, a total of six population-specific mitolineage haplotypes were identified among the mahseer samples analyzed, which this offers hints towards its taxonomical landscape.

A Current Update on the Distribution, Morphological Features, and Genetic Identity of the Southeast Asian Mahseers, Tor Species.

The king of rivers or mahseer comprises three genera: Tor, Neolissochilus, and Naziritor, under the Cyprinidae family. The Tor genus has been classified as the true mahseer due to the presence of a median lobe among the three genera. The Tor species are widely distributed across Southeast (SE) Asia, and 13 Tor species have been reported previously: Tor ater, Tor dongnaiensis, Tor douronensis, Tor laterivittatus, Tor mosal, Tor mekongensis, Tor putitora, Tor sinensis, Tor soro, Tor tambra, Tor tambroides, Tor tor and Tor yingjiangensis. However, the exact number of valid Tor species remains debatable. Different and unstandardized approaches of applying genetic markers in taxonomic identification and morphology variation within the same species have further widened the gap and ameliorated the instability of Tor species taxonomy. Therefore, synchronized and strategized research among Tor species researchers is urgently required to improve and fill the knowledge gap. This review is a current update of SE Asia's Tor species, outlining their distribution, morphology, and genetic identification. In addition, the present review proposes that there are ten valid Tor species in the SE Asian region. This list will serve as a template and standard to improve the taxonomy of the SE Asian Tor species, which could serve as a basis to open new directions in Tor research.