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1.
    
  1. The Pyrenean desman (Galemys pyrenaicus) is an endangered, semi‐aquatic, insectivore mammal, endemic to the northern Iberian Peninsula and the Pyrenees. Owing to its small populations, evasive behaviour, and nocturnal activity, knowledge of its ecological requirements is still limited. Continuing population decline over most of its distribution range – even in regions where water quality has clearly improved – points to other factors as the main conservation threat. Nevertheless, at present there is a lack of information on its habitat preferences within its area of occupancy (e.g. stream microhabitat characteristics), a key point for assessing or improving its habitat.
  2. This study used radio‐telemetry data to determine the use of space at microhabitat level by the desman, and how this changed depending upon environmental conditions.
  3. Desmans were studied in two contrasting rivers in the Basque Country (northern Iberian Peninsula): Elama, a nearly pristine stream, and the Leitzaran, a clean‐water stream affected by hydropower diversions. Fifteen desmans were captured and radio‐tracked in Elama and 16 were captured and radio‐tracked in the Leitzaran, and nocturnal activity points were assigned to one of three habitat types: riffles, runs, or pools. Habitat use was compared against availability to measure habitat selection in each stream and between streams.
  4. Desmans selected riffles positively and pools negatively, with this selection being stronger in the Leitzaran.
  5. The results highlight the ecological relevance of riffles as foraging habitats of desmans, and therefore as key features for their conservation. It suggests that channel modifications that reduce the areal cover of riffles impair habitat quality for this species. In addition, water diversion for hydropower is likely to be detrimental for desmans, as it reduces discharge and flow velocity in the bypassed river sections.
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2.
    
  1. The Pyrenean desman (Galemys pyrenaicus) is an endangered stream-dwelling insectivore endemic to the Iberian Peninsula and the north of the Pyrenees. It favours riffles over slow habitats such as runs or pools, yet it is still unclear whether habitat preference is based on prey availability or on other factors, such as mechanical constraints on its hunting habits.
  2. Desman diet and prey selection were analysed along the pristine Elama Stream and the slightly modified Leitzaran Stream in the Basque Country, Spain.
  3. In each stream the prey consumed were identified by metabarcoding 94 desman faeces, and prey availability characterized from 10 Surber samples taken in each habitat type (riffles, runs and pools). Invertebrates were sorted and identified, the biomass of each taxon was calculated, and their DNA was also extracted, amplified using PCR, and sequenced to build a reference database.
  4. Prey availability and diet varied between streams. Desmans positively selected shredders and invertebrates that live on the substrate, and selected against taxa that live in fine sediment, taxa with hard shells or those that are highly mobile. The diet of desmans was more selective in the Elama, the stream with better ecological status. Food availability did not differ among habitats, and therefore does not explain the preference of desmans for riffles; rather, mechanical constraints to deal with buoyancy and physical habitat heterogeneity were hypothesized to be the reason behind the habitat preference.
  5. The results suggest that promoting the formation of riffles in streams can improve the situation of some desman populations living in degraded habitats.
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3.
  1. In ancient times, the distribution range of the Mediterranean monk seal (Monachus monachus) extended all over the coasts of the Mediterranean, the Black Sea and parts of the north‐eastern Atlantic coast.
  2. Nowadays, the species is classified as Endangered and the current total world population is stated to consist of ~700 animals, though numbers mostly express best estimates. Distribution patterns in documents of international authorities from the last 15 years indicate the species' extinction in a number of Mediterranean countries, whereas in some of them only a few individuals are thought to survive and in others the status is unknown.
  3. This study analyses recent monk seal sightings over the period from 2000 to 2014 in the Mediterranean Basin. The locations of the sightings cover most of the study area and indicate a spreading of individual seals or a more stable presence in regions where the species was considered extinct.
  4. The investigation pointed out that efforts for the protection of monk seals, the most endangered marine mammal in Europe, should encompass all areas where monk seal sightings have been recorded, including the protection and conservation of potential suitable habitats in countries where the species apparently no longer exists.
  5. Appropriate conservation measures, such as the establishment of marine protected areas and sustainable management of fisheries, will aid natural recolonization and enhance gene flow between distant regions throughout the Mediterranean Basin, allowing the reconnection of distant populations or individual animals.
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4.
    
  1. New Zealand sea lions are incidentally killed in trawl fisheries around the Auckland Islands with most mortality having been attributed to the Auckland Islands squid fishery. Fishery management measures include the establishment of a 12 nautical mile marine reserve around the Auckland Islands excluding all fishing within that range, the instigation of mortality limits that can trigger spatio‐temporal closures, and widespread use of a ‘Sea Lion Excluder Device’ (SLED) that allows sea lions to escape from a trawl net. Although there has been controversy regarding SLED efficacy, the evidence from numerous research trials and assessments is that SLEDs have contributed to reduced rates of sea lion bycatch in the Auckland Islands squid fishery.
  2. Population viability analysis (PVA) modelling, using VORTEX, of the Auckland Islands New Zealand sea lion population was undertaken to ascertain if the reported levels of bycatch of sea lions in trawl fisheries around the Auckland Islands are sustainable following substantial and effective mitigation to reduce bycatch, particularly in the Auckland Islands squid fishery.
  3. Modelling indicated slow population growth of the Auckland Islands New Zealand sea lion population with current bycatch estimates from all Auckland Islands trawl fisheries. Additional modelling seeking explanations for observed population declines over the last decade indicated that epizootic events that reduce pup production may have a greater impact on population growth, especially if these events are more frequent than previously assumed.
  4. Modelling results suggest that sea lion bycatch in the squid fishery and other trawl fisheries around the Auckland Islands is unlikely to be currently having a significant impact on the Auckland Islands New Zealand sea lion population. Therefore, resources should be directed towards other hypotheses for any continued sea lion population decline as well as continued refinement of mitigation techniques to reduce fisheries‐related mortality.
Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

5.
    
  1. Numerous freshwater species are recreationally harvested, yet conservation concerns are often ignored. This may lead to conflict between fisheries and conservation management for a species.
  2. Approximately one‐third of freshwater crayfish species globally are threatened with extinction, including the Murray crayfish, Euastacus armatus (von Martens, 1866) in south‐eastern Australia. There has been substantial commercial and recreational fishing of E. armatus since European settlement, as well as other threats such as poor water quality (e.g. hypoxic ‘blackwater events’ during floods).
  3. A stochastic population model was developed for three regional populations of male and female E. armatus, and was used to examine the effects of fishing and hypoxic blackwater disturbance on a Murray crayfish population in a lowland region.
  4. The results indicate that the Murray crayfish population in the lowland region faces increasing risks from increasing fishing pressure, together with low frequencies of hypoxic blackwater disturbance only. Testing various fishery regulations, the modelling demonstrated that recent changes to the ‘slot size’ in occipital carapace length of 10–12 cm for legally harvesting crayfish was a suitable protection measure given the background levels of hypoxic blackwater disturbance, balancing fishing and conservation concerns. Although higher slots (11–13 cm and 12–14 cm) were less sensitive to higher fishing pressures, the recreational harvest declined.
  5. The model was most sensitive to early life‐history survival rates; however, sensitivity analysis of model variability also indicated that E. armatus may be susceptible to highly variable environments (not to be confused with highly variable flows).
  6. This study demonstrates the successful integration of fishing and conservation in a flexible risk framework for this threatened freshwater crayfish species; furthermore, fisher expectation can be managed by assessing the impact on harvest of potential changes to fishing regulations. This approach is easily transferable and would improve the management of other recreationally fished species facing multiple threats.
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6.
    
  1. Effective management of critically endangered sawfishes can be a difficult task, in part due to interspecies misidentification. Current methods for identifying sawfishes can be impractical as they are based on morphological features that are often unobservable. Further exploration is required to develop a more reliable means of identification.
  2. This study explored the utility of sawfish rostra in determining the species, size and sex of sawfishes, as rostra are commonly the only feature of a sawfish observed by fishers or present in public and private collections.
  3. A morphometric and meristic database consisting of over 1100 narrow sawfish (Anoxypristis cuspidata), dwarf sawfish (Pristis clavata), largetooth (or freshwater) sawfish (Pristis pristis; formerly Pristis microdon) and green sawfish (Pristis zijsron) rostra from Australian waters, was statistically analysed.
  4. Identification of sawfishes was found to be possible through the use of the variables: inter‐tooth spacing, standard rostrum width/standard rostrum length, standard rostrum length/total rostrum length, rostrum tip width/standard rostrum length, and/or rostral tooth count range, although the distinguishing variables were species‐dependent.
  5. The relationship between standard rostrum length and total length was also observed to vary substantially between most species. Models for estimating total length from standard rostrum length are provided.
  6. This study has provided a tool that can be used to identify accurately the species and size of sawfishes by their rostra, and therefore can assist in clarifying historical and contemporary sawfish records, nomenclature and distributions. A better understanding of these issues should allow sawfish conservation strategies to become more focused, and thus more effective.
Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

7.
    
  1. Historical and current information on sawfish distribution and abundance in African waters is limited, yet such information is essential in order to effect conservation strategies for this group of critically endangered elasmobranchs.
  2. During a study of sawfishes in the Gambia River in 1974 and 1975 fishermen were interviewed and sawfishes and rostra were collected in order to assess the species and size classes present and the spatial distribution of sawfishes.
  3. Largetooth sawfish (Pristis pristis) were common in the Gambia River during this period and could be found several hundred kilometres upriver, extending into Senegal.
  4. Interviews conducted with fishermen in 2014 at key fish landings sites along the Gambian coast and upriver suggest that sawfish are now rarely encountered, although a small number of fishermen stated that they had caught a sawfish within the last 5 years.
  5. The use of nets was perceived to be the main cause of sawfish decline. There was little mention of any cultural importance of sawfish, which were considered useful primarily as a source of food.
  6. Sawfish declines are resulting in a shifting baseline syndrome, whereby local knowledge of sawfish ecology and cultural importance is being lost in the West Africa region.
  7. These data demonstrate for the first time that the Gambia River was historically a key habitat for freshwater sawfish and as such, should be considered in any future conservation actions for sawfishes in the West Africa region.
Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

8.
    
  1. The abundance, distribution and diet of the short-beaked common dolphin were investigated as part of the first detailed study on cetacean populations in the North Aegean Sea. Since 2004, the area has been proposed by national and international entities as a marine protected area for common dolphins and other cetacean species owing to its high biodiversity.
  2. Abundance and distribution were investigated between 2005 and 2013 through dedicated scientific marine transect surveys, covering 14,701 km, in sea conditions of Beaufort sea state 3 and below. The line-transect sampling method was used to estimate relative abundance, using Distance 6.0 software. Encounter rate for this species in the study area was estimated to be 0.24 groups/100 km (1.5 dolphins/100 km), with a mean group size of 6.88 (SE = 1.90).
  3. Common dolphin sightings were analysed for correlations with eight environmental variables (distance from the coast, depth, slope, median salinity, gradient of salinity, median temperature, gradient of temperature and mean current) using generalized additive modelling. Common dolphin sightings were significantly correlated to depth, temperature and salinity.
  4. Stomach-content analyses were performed on eight suitable samples from common dolphins stranded in the study area. The trophic level of the species was calculated, indicating that this species is a top predator.
  5. This research provides the first estimates for abundance and distribution and the first diet analysis for this Mediterranean Endangered dolphin species in the study area based on a year-round long-term study.
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9.
    
  1. Monitoring fish movement can test the effectiveness of environmental flow releases when they are used to trigger spawning behaviour. Environmental flow releases have been used to enhance Australian grayling (Prototroctes maraena) spawning in regulated rivers in south‐eastern Australia and resource managers require knowledge of the effectiveness on the conservation of this threatened species.
  2. Australian grayling movement was monitored in the Thomson River, south‐eastern Australia using acoustic telemetry to determine whether the species undergoes a spawning migration, where they migrate and timing in relation to environmental flow releases. Drift netting was used to verify whether spawning took place.
  3. Adult Australian grayling undertook downstream spawning migrations (up to 140 km) to the lower Thomson River, coinciding with environmental flow releases.
  4. The findings of this study support the use of environmental flow releases to trigger spawning migrations by Australian grayling. In addition, they provide managers of other species with an example of the potential effectiveness of environmental flow releases in triggering fish migration or spawning that can assist in rationalizing this management intervention.
Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

10.
    
  1. Based on optimal foraging theory, animals are expected to maximize foraging benefits whilst minimizing risks. Despite risking being subjected to anthropogenic impacts such as water contamination, marine traffic, and underwater noise, estuaries have been identified as the preferred habitat of the Indo‐Pacific humpback dolphin (Sousa chinensis, IPHD). However, it remains unclear why this vulnerable species favours such risky habitats.
  2. Here, an exploratory case study in Zhanjiang estuary, China, was conducted to test the hypothesis that IPHDs select estuarine habitats as a trade‐off that maximizes foraging opportunities whilst minimizing the risk of mortality.
  3. The results showed that IPHDs accept greater mortality risks for higher food rewards but select habitats with lower risks when food rewards are similar between two locations.
  4. Although this type of information is important for underpinning models for individual dolphins, its principal role is to show environmental protection agencies why IPHDs favour estuaries despite the increased mortality risks.
  5. Habitat conservation plans should carefully consider prey stocks, possibly through the presence of marine protected areas near estuaries, as local overfishing may lead vulnerable cetacean populations to take greater risks.
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11.
    
  1. With estimates of fewer than 1000 mature individuals in the wild, the critically endangered Siamese crocodile, Crocodylus siamensis Schneider, 1801, is one of the least known and at the same time most threatened crocodilian species in the world. Populations have already been depleted to approximately 20% of their former size with habitat destruction, alterations, and loss being the main drivers of population declines.
  2. Habitat suitability models were computed using a combination of bioclimatic and remote sensing variables as environmental predictors to evaluate habitat suitability and coverage by designated protected areas across the species’ distributional range. In addition, population connectivity as well as current and future habitat fragmentation through dam construction was assessed by performing population connectivity models.
  3. Habitat suitability models show the spatial extent of suitable habitat to be high (46%), although only a small proportion is covered by designated reserves (11%). Population connectivity models showed remnant populations to be highly fragmented. Considering habitat suitability, coverage of reserves and population connectivity the lower Mekong River Basin stretching from the Xe Champhon and Xe Xangxoy rivers in Lao PDR to the Srepok and Sekong rivers in eastern Cambodia seem to be particularly important for future conservation prioritization for C. siamensis.
  4. The presently established protected area network is unsatisfactory in terms of size and population connectivity and needs to be significantly improved to successfully sustain viable populations of the critically endangered Siamese crocodile in the future.
Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

12.
    
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13.
    
  1. The Adriatic Sea is one of the Mediterranean areas most heavily impacted by fishing and other human stressors. The northern part of the basin has been certified as an Important Marine Mammal Area because of the regular occurrence of common bottlenose dolphins, Tursiops truncatus.
  2. Boat surveys, totalling 76 days at sea and 10,711 km of navigation, were conducted between April 2018 and October 2019 to assess cetacean abundance within a 3,000-km2 area off Veneto, Italy. Bottlenose dolphins – the only marine mammal species observed – were encountered on 52 days and were tracked for 81 h and 26 min, resulting in 15,066 dorsal fin photographs of high quality and resolution.
  3. Various capture–recapture models were applied on individual photo-identification datasets. Model-based estimates indicate that approximately 600 individuals occurred within the study area during the sampling period in both years. Abundance varied monthly: minimum estimates were obtained in May 2018 (291 individuals; 95% CI 134–630) and May 2019 (121; 95% CI 20–721), whereas maximum estimates were obtained in September 2018 (385; 95% CI 310–477) and October 2019 (494; 95% CI 378–645).
  4. Evidence provided by this study can be used to complement and validate coarse ‘snapshot’ information from recent aerial surveys of the entire Adriatic Sea, and to enforce management action mandated by the European Community (EC) Habitats Directive and Marine Strategy Framework Directive, as well as guiding the EC’s Maritime Spatial Planning.
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14.
    
  1. Using population estimates that were made regularly between 2001 and 2013, the state of recovery of arapaima populations and their IUCN conservation status were assessed after they were almost extirpated from the upper Essequibo basin, Guyana. Recovery rates were compared across multiple areas with different degrees of access by fishers to evaluate effectiveness of conservation efforts.
  2. Population estimates were also used to investigate the influence of environmental factors on arapaima abundance in lakes with different morphometries, vegetation, and water types and to determine the relationship between the numbers of spawning individuals and subsequent recruits (at about age 2 years).
  3. The most recent census conducted in November–December of 2013 indicated a 5.6-fold increase in overall abundance compared with 2001, with 4,591 individuals, of which 1,932 were juveniles (1.0–1.5 m total length) and 2,659 adults.
  4. Assessment of conservation status following IUCN criteria indicated that arapaima populations in the upper Essequibo basin in 2001 would have been considered borderline Critically Endangered, but in 2013 after conservation interventions, status would be categorized as Near Threatened.
  5. Arapaima in the Essequibo basin appear to favour larger but shallow lakes with low conductivity, clear water, and abundant aquatic macrophytes. Stock–recruitment relationships suggest that the entire upper Essequibo basin population may still be growing and that there is approximately a 1:1 juvenile to adult ratio. This ratio of juveniles to adults across all areas suggests a paucity of young fishes to sustain overall population growth, which might reflect widespread illegal removals of young fishes in the basin.
  6. Comparisons of arapaima densities in the upper Essequibo basin with those at four localities across the Amazon Basin, suggest that with enhanced conservation efforts in the Essequibo, populations could potentially increase two-fold or more.
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15.
    
  1. Dried gill plates from manta and devil rays, some of the world's most biologically vulnerable fishes, have become a valued commodity in Asian dried‐seafood and traditional Chinese medicine markets. This trade is a primary driver of fisheries, which have led to declines in many mobulid populations.
  2. With no reliable trade statistics and scarce data on mobulid fisheries, this study estimates the number and species of mobulids required to supply this trade, and investigates the consumers and suppliers involved and drivers of demand. Following preliminary market research, 525 trader surveys were conducted in Hong Kong, Singapore, Macau, Taiwan, and southern China.
  3. Guangzhou, China was identified as the centre of the trade accounting for 99% of total estimated market volume of 60.5 tons of dried gill plates in 2011, increasing to 120.5 tons by 2013. The estimated number of mobulids converted from tons of gill plates more than doubled over the period to 130 000, comprising 96% devil rays, Mobula japanica, Mobula thurstoni, and Mobula tarapacana, and 4% Manta spp. By 2015 the Guangzhou market had declined sharply, reportedly due to conservation campaigns and government policies. However Hong Kong's gill plate sales increased dramatically between 2011 and 2015.
  4. China, Indonesia, Vietnam, Sri Lanka, and India were reported most frequently as gill plate sources.
  5. Vendors recommend gill plates (trade name pengyusai) for ailments ranging from acne to cancer and as a general health tonic. While pengyusai is a new addition to traditional Chinese medicine literature and is rarely prescribed by traditional medicine practitioners, it is readily available over the counter and aggressively marketed by vendors.
  6. Working in concert with consumer demand reduction efforts, increased measures to restrict mobulid fisheries and trade are recommended to prevent further population declines of these highly vulnerable species.
Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

16.
    
  1. Sawfishes (Family: Pristidae) are one of the most imperilled fish families worldwide. There is an increasingly urgent need to better understand the biology, ecology, and population status of the five sawfish species to develop more effective conservation measures. The dwarf sawfish, Pristis clavata, is one of the least researched members of the pristids, with literature limited to analysing disparate datasets or collations of rare encounters in northern Australia.
  2. This study examined the spatial ecology of dwarf sawfish using targeted surveys and acoustic telemetry to determine its habitat use in a macrotidal estuary in northern Australia. Seventeen dwarf sawfish were tagged with acoustic transmitters and monitored in the Fitzroy River estuary and adjacent King Sound (Kimberley, Western Australia) between August 2015 and November 2017.
  3. Dwarf sawfish observed within the Fitzroy River estuary and King Sound were juveniles, ranging between 740 and 2,540 mm in total length. Catch per unit effort of dwarf sawfish in the late dry season was relatively high in the estuary, with the catch rate in 2015 being one of the highest reported for any sawfish species.
  4. Acoustic detections revealed a distinct seasonal pattern in the use of different parts of the estuary and King Sound, which was found to be driven by salinity. Dwarf sawfish predominately occupied a single large pool near the terminus of the tidal limit in the late dry season (August–November), before transitioning to regions in closer proximity to the river mouth or in King Sound in the wet and early dry seasons (December–July).
  5. Given the high abundance and residency of dwarf sawfish in the Fitzroy River estuary, this area is an important nursery for the species during the late dry season and should be formally recognized as a habitat protection area for the species.
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17.
    
  • 1. An internationally important population of the freshwater pearl mussel (Margaritifera margaritifera) was rediscovered in a small river in north‐west Russia.
  • 2. A survey of visible mussels in 2008/2009 indicated an estimated population of 40 000 individuals. This is the largest population currently known in the Leningrad oblast and is comparable with the entire pearl mussel population of some western European countries.
  • 3. The average density of visible mussels was 29.6 individuals m?2 in the middle part of the river. In the four largest mussel beds maximum densities of 1000+ individuals m?2 were recorded. Such densities are exceptional and have not been reported elsewhere in Europe during the last 100 years.
  • 4. Live juvenile mussels were recorded, indicating that that this population is viable, although further investigation is required to establish its status.
  • 5. Analysis of the population age structure, based on the measurement of empty shells, showed an age class distribution similar to those reported for other healthy Margaritifera populations.
  • 6. Only two live juveniles were found. However, this is likely to be due to the survey being restricted to counts of visible mussels only, and the age structure being based on the analysis of dead shells.
  • 7. The population's current status and possible reasons for its survival in this river are discussed. Conservation measures should include the construction of a fish ladder to make fish migration through the culvert possible, removal of a metal screen preventing fish migration from the upper reaches of the river to the lake, reduction of recreation activities, and providing the local children's camp with water treatment facilities. Copyright © 2011 John Wiley & Sons, Ltd.
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18.
    
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19.
    
1. The freshwater pearl mussel Margaritifera margaritifera is threatened throughout its Holarctic range, but the occurrence of this species is insufficiently mapped. For the conservation of M. margaritifera, it is important to identify populations more comprehensively. 2. Traditionally mussels have been searched for visually using techniques such as diving and aquascope, both of which are potentially time‐consuming and demanding survey methods. 3. In this study, a new search method is presented. As glochidia of M. margaritifera are larval parasites on the gills of salmonid fish, electrofishing and non‐destructive examination of salmonids with the naked eye may reveal the presence of glochidia and therefore the occurrence of M. margaritifera in watercourses. This method was tested in both the field and laboratory in northern Finland. 4. In summer, when M. margaritifera glochidia were large, the status of salmonids being infected or uninfected by M. margaritifera was correctly identified with the naked eye with 62, 80, 88 and 93% accuracy in four streams sampled, 96% accuracy in the laboratory, and 100% accuracy in all cases when at least 20 glochidia per fish were present. Intensity of infection was also assessed successfully; a specifically tailored, qualitative abundance score correlated significantly with the real number of glochidia. However, during autumn with small glochidia freshly attached to fish, glochidia infection could be observed only under microscopic examination. 5. When the method was used in 40 previously incompletely surveyed tributaries, three M. margaritifera populations were found. The infection in salmonids was observed always with the naked eye, being subsequently confirmed microscopically. The existence of adult mussels in two of these rivers was also confirmed. 6. The results indicate that electrofishing and a relatively quick naked‐eye check of salmonids provides a new, non‐destructive, and potentially cost‐effective way to search for new, previously unrecorded M. margaritifera populations. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

20.
    
  1. Four valid species are currently recognized in the Neotropical migratory genus Salminus: Salminus brasiliensis, Salminus franciscanus, Salminus hilarii and Salminus affinis. However, molecular evidence strongly suggested that two different species might be contained under the taxonomic denomination Salminus brasiliensis. Therefore, the geographical distribution of each entity was evaluated in order to understand their contribution to the different stocks of major river networks in South America.
  2. Major river networks of the La Plata River basin were explored to characterize the geographical distribution of the two genetic lineages. To characterize further the genetic partitioning within each lineage of S. brasiliensis, a haplotype analysis was conducted. The 5′ region of the mitochondrial COI gene was used as the molecular marker. In total, 45 fish samples of S. brasiliensis from 19 sites in Argentina, Brazil and Paraguay were sequenced. Additional COI sequences of S. brasiliensis, S. franciscanus and S. hilarii were gathered from public databases.
  3. All samples of S. brasiliensis comprised two different mitochondrial lineages. Accordingly, phylogenetic tree topologies segregated the complete set of sequences into two disparate clusters. One of these clusters was far closer phylogenetically to S. hilarii than to other S. brasiliensis.
  4. While one of the genetic lineages of S. brasiliensis seemed mostly restricted to the upper Paraná River, the other showed a widespread distribution along major river networks of the basin.
  5. Fifteen unique haplotypes were identified and collapsed. Salminus hilarii and S. franciscanus have private haplotypes. In S. brasiliensis, each mitochondrial lineage also hosts a set of unshared haplotypes.
  6. The sympatry of two different putative species within S. brasiliensis together with their unshared haplotypes present a difficult situation for management and conservation that calls for timely solutions.
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