Endemic Cyprinid Research Articles

Predicting climate change impacts on the distribution of endemic fish Cyprinion muscatense in the Arabian Peninsula.

Freshwater fishes are facing considerable threats in the Arabian Peninsula which is considered as a highly stressed region in the Middle East. It is predicted that northern Oman is likely to face decreasing rainfall and increasing temperature in coming decades. In this study, we focused on an endemic cyprinid fish Cyprinion muscatense, as a model to investigate impacts of climate change on the mountain fishes inhibiting in this arid region. This species is expected to be strongly affected by climate change because of its limited distribution range in a montane area surrounded by lowlands and sea, limiting the species in shift to other areas. We used an ensemble approach by considering two regressions-based species distribution modeling (SDM) algorithms: generalized linear models (GLM), and generalized additive models (GAM) to model the species habitat suitability and predict the impacts of climate change on the species habitat suitability. Based on the distribution models, the montane area located in northeastern Oman was identified as the most suitable habitat for this species. Our results indicate that, even under the minimum greenhouse gas emissions scenario (RCP 2.6), climate change will produce a high reduction in its potential future habitats. According to the results of percent contribution, elevation and annual minimum temperature were the most important variables in predicting the species suitable habitats. Results also showed that only a small percentage of suitable habitats for the species within boundaries of protected areas. Therefore, the impact of climate change on the species appears particularly alarming. Although our study was restricted to a single cyprinid freshwater species, decreases in potential habitats are likely predicted for other cyprinid fish species restricted to the mountains of this region, suggesting severe consideration is needed for aquatic systems in future conservation planning, especially for endemic freshwater fishes.

Social buffering of oxidative stress and cortisol in an endemic cyprinid fish

Fish exhibit complex social behaviours that can influence their stress levels and well-being. However, little is known about the link between social interactions and stress in wild fish, especially in running water environments. While many studies have explored the stress axis in fish, most have focused on specific social contexts, leaving gaps in understanding stress responses to social changes. Our study investigated collective behaviour and stress in wild Italian riffle dace (Telestes muticellus) in a controlled experimental setup simulating a natural river system. Results reveal that group-living fish have lower cortisol and oxidative stress levels in muscle tissue compared to solitary counterparts, suggesting a calming effect of conspecific presence. Additionally, we observed upregulated expression of antioxidant enzymes in group-living fish, indicating potential benefits to antioxidant defence systems. These insights shed light on the dynamic relationship between group behaviour and stress in wild fish within running water habitats and emphasise the use of multidisciplinary approaches.

Population genetic diversity and structure of the Taiwan endemic cyprinid fish Candidia barbata (Cyprinidae): human intervention

Population genetic diversity and structure of the Taiwan endemic cyprinid fish Candidia barbata (Cyprinidae): human intervention

The Impact of Weir Construction in Korea's Nakdong River on the Population Genetic Variability of the Endangered Fish Species, Rapid Small Gudgeon (Microphysogobio rapidus).

Microphysogobio rapidus, an endemic cyprinid fish species found exclusively in Korea, has been identified in only two tributaries of the Nakdong River. The species predominantly occupies the near-gravel bottom waters within shallow sections of the middle and lower reaches of the river, characterized by swift currents. M. rapidus is currently recognized as a critically endangered species due to its distinct habitat preference, as well as the negative impacts of stream dam development and water environment pollution. In this study, we used 10 microsatellite markers to examine the genetic diversity of M. rapidus in the upper Nam (UN), lower Nam (LN), and Deokcheon Rivers (DC) in Korea, with a specific focus on assessment of the impact of dam development. Fish sampled from the UN and LN showed a greater average number of alleles and allelic richness (A = 18.3-18.4, AR = 13.8) compared to those from DC (A = 11.8, AR = 11.5). The observed heterozygosity among the fish examined ranged from HO = 0.748 (LN) to 0.766 (DC). All three fish groups exhibited a significant departure from Hardy-Weinberg equilibrium (HWE) (p < 0.05). Despite having the largest effective population size (Ne = 175 and 157, respectively), the fish sampled from UN and LN showed the highest inbreeding coefficients (FIS = 0.056-0.053, respectively), which were highly significant (p < 0.01). In contrast, the fish sampled from DC exhibited the smallest effective population size (Ne = 61) and showed an inbreeding coefficient close to zero (p > 0.05). BOTTLENECK analysis and estimated M-ratio values (0.341-0.372) revealed indications of past population size reduction in all fish groups examined. No significant genetic differentiation (FST < 0.05) was detected using the DAPC, STRUCTURE, and AMOVA among the fish studied. However, pairwise comparisons of FST between fish sampled from the Nam and Deokcheon Rivers revealed significant values (p < 0.001) ranging from 0.013 to 0.014. In addition, the closest genetic distance (0.026) was observed between UN and LN, while the greatest distance (0.087) was found between UN and DC. Analysis of gene flow rates among the fish examined indicated asymmetrical gene exchange within the Nam River, which was 31.51% in the downstream direction (from UN to LN), with a minimal gene flow rate (0.41%) in the upstream (from LN to UN) direction. The opposite trend was recorded between DC and LN, with a higher gene flow rate (29.74%) in the upstream direction compared to the downstream direction (0.12%). Our study highlighted the importance of implementing long-term conservation efforts focused on maintaining river integrity by removing water barriers such as weirs that impede fish migration and implementing active protection measures, such as aquaculture breeding and reasonable stocking practices, to preserve M. rapidus in the study area.

Length frequency distribution, growth, and condition factor of the endemic cyprinid fish Poropuntius tawarensis, in Lake Laut Tawar, Central Aceh, Indonesia

The Poropuntius tawarensis fish is an endemic fish of the family Cyprinidae found in Laut Tawar Lake, and has been listed on the Red List. This study aims to reveal the frequency of length distribution, growth patterns and condition factors of the fish in the lake as basic information for conservation. The study was conducted from January to May 2022 in the Laut Tawar Lake of Central Aceh. Sampling was conducted at four sampling sites based on representative activities on the lake. The location of the study was determined based on differences in environmental characteristics, namely Station 1 (Teluk One-One), Station 2 (Bewang), Station 3 (Gegarang) and Station 4 (Kebayakan). The results showed that the fish at Bewang Station was relatively higher in terms of the frequency of the length distribution. The growth pattern of male and female fish was negative allometric (b<3).The condition factor of the three stations was relatively the same ranging from 0.94 to 1.39, but it was different from the one-one station with a condition factor of 0.01.The value of the condition factor that can be obtained had insignificant differences every month, namely 1.12±0.38 (January), 1.00±0.49 (February), 0.93±0.55 (March), 0.85±0.59 (April), and 1.17±0.32 (May).

Imaging scale surface topography of an endemic cyprinid fish, Garra sharq from the Arabian Peninsula: An integrated optical light and scanning electron microscopy approach

AbstractThe optical light microscopy and scanning electron microscopy techniques have proven to play a key and noteworthy role in the advancement of morphological studies in general, and in investigating fish scale morphology in particular. These techniques have illustrated several hidden architectural structures in scales that contribute effectively to fish identification and classification. The scale morphological and topological characters such as type, size, shape, lateral surface, focus position, circuli appearance, radii type, lepidonts, and posterior and anterior margin shapes were obtained using macro‐ and microscopic analysis in six body regions for three size classes of Garra sharq, a cyprinid endemic fish of the Arabian Peninsula. The general scale type in the studied G. sharq species was a basal elasmoid cycloid and a sectioned type. As a protective structure, the scales display several specific characteristics including firm attachment to the fish body, overlapping, and thin structure with a high surface area and high strength. These characteristics improve scale resistance to penetration, increase protection against mechanical injury and microbial infection, enhance scale flexibility, reduce fish weight (reduce friction drag), and increase scale transparency. The scales demonstrate plasticity in focus shape, size, and position in the six fish body parts and fish size groups. The examined scales displayed narrow or wide grooves (radii) in three types including primary, secondary, and tertiary present in all four scale fields (anterior, posterior, and laterals), thus a tetra‐sectioned type that is almost specific to the genus Garra. This characteristic also increases scale flexibility. The rostral margin of scales was characterized by the presence of waved and striate types. The lepidont shape and size varied being blunt, flat, pointed, tiny, sharp, short, and long. Some of these scale characters and their morphologies could be used as an alternative tool for identification, classification, and phylogenetic interpretation among the different freshwater fish species and genera.

The first complete mitogenome of Onychostoma ovale (Pellegrin & Chevey, 1936) with phylogenetic analyses

Onychostoma ovale (Pellegrin & Chevey, 1936) is an endemic cyprinid fish that is widely inhabited in southern China, Vietnam, and Laos. In the present study, we first reported the complete mitochondrial genome of O. ovale. The mitogenome contained 16,600 bp with AT content of 56.2% and comprised of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and one control region (D-loop). Phylogenetic analyses suggested that Onychostoma species formed two major clades and the subspecies of O. ovale had close relationship with O. rarum. The mitochondrial genome of O. ovale provided a key aid for population genetics and phylogenetic inferences of Onychostoma in future research.

Seasonal Differences in Water Pollution and Liver Histopathology of Iberian Barbel (Luciobarbus bocagei) and Douro Nase (Pseudochondrostoma duriense) in an Agricultural Watershed

Histopathology has been used as a very useful tool to provide information on the severity of tissue damage, injuries, and organ functionality. Thus, this work aimed to assess whether seasonal variations (summer and winter) in water quality had consequences on the liver histology of Iberian barbel (Luciobarbus bocagei) and Douro nase (Pseudochondrostoma duriense). The research was carried out in the Vilariça River, a tributary of the Sabor River in Portugal, which is used as spawning grounds by these endemic cyprinids. The liver histopathological changes, assessed through a semi-quantitative system, allowed the identification of 13 histopathological changes located in the hepatic parenchyma, bile duct, and blood vessels. The histopathological changes with a higher prevalence in both species were vacuolization of hepatocytes, endothelial rupture, necrosis, fibrosis, and degenerative vacuolization. The results showed that the severity degree of liver histological alterations ranged between moderate and severe, and the major severity degree was observed in L. bocagei, in the summer season, and at the sampling points located in the downstream and middle stream. The canonical analysis indicated that the exposure of fish to metals may increase the potential risk of liver damage. Thus, in the summer, the high concentrations of Fe, Cu, Zn, As, and Mn justified the prevalence of the biliary duct epithelial detachment, in both species, and the hyperplasia of biliary epithelium, in L. bocagei. In the winter, the high TSS and Cd, Ni, and Cr concentrations justified the prevalence of congestion of blood vessels and degenerative vacuolization in both species. The higher hepatosomatic index of fish caught in the winter was due to the high presence of degenerative vacuolization and hepatocyte vacuolization. The severity of liver histopathological changes reflected differences in the type of contaminants in different seasons and sampling periods, and was thus proven as a valuable indicator of water quality.

A potential endemic cyprinid for aquaculture and food security: The embryonic development of the Bornean spotted barb Puntius sealei (Herre, 1933)

The Bornean Spotted Barb is endemic fish species and widely distributed throughout Borneo in various freshwater bodies and can be considered as a potential aquaculture candidate for food security and the ornamental trade. However there has yet to be scientific studies on the early life history and developmental stages of this species. Thus the present study reveals the embryonic development of Puntius sealei embryo, from fertilization to post-hatching using the induced breeding method. The induced spawning on P. sealei using Ovaprim hormone at a dose of 0.5 ml/kg for females and 0.25ml/kg for males respectively was successfully conducted and the embryonic development of the fertilized eggs were observed. The zygote, cleavage, blastula, gastrula, segmentation, and larval phases were the six major stages of embryogenesis that investigated in this experiment. This study contributed major knowledge to the early developmental biology of this particular species. The information will be useful for accessing the potentiality of this species for aquaculture as well as the management, and production of the species. Asian Australas. J. Food Saf. Secur. 2021, 5 (2), 55-62

Fish morphology and passage through velocity barriers. Experience with northern straight-mouth nase (Pseudochondrostoma duriense Coelho, 1985) in an open channel flume

Knowing the relationship between size, morphological traits and swimming performance of fish is essential to understand the swimming capacity to successfully surpass these obstacles and the selective pressure that barriers in rivers and streams could exert on fish. Northern straight-mouth nase, an endemic potamodromous cyprinid fish species from the Northwest of the Iberian Peninsula, was selected to carry out volitionally swimming performance experiments in an open channel against three different flow velocities, using telemetry and video cameras. The use of thin-plate spline, on 10 landmarks, evidenced unknown patterns linked to velocity barriers. At lower flow velocity, size is the main factor explaining the swimming performance; thus, large individuals swim up more efficiently. In contrast, at high flow velocities, shape becomes the essential explanatory variable; thereby, streamlined body shapes with a higher relative position of the tail and a narrower caudal peduncle are more efficient. The obtained results show the existence of a relationship between fish morphology and swimming performance, with potential consequences due to selection pressures associated with velocity barriers and their implications on behavioural and dispersal processes. To sum up, velocity barriers could exert a selection pressure on nase populations, so the fishway design and removal should be (re)considered.

Genetic structure and demographic history of endangered Alburnus tarichi (Güldenstädt, 1814) populations from Lake Van basin in Turkey inferred from mtDNA analyses

Genetic diversity, genetic structure, and demographic history of the endemic and endangered cyprinid species Alburnus tarichi based on samples from 17 populations consisting of resident and potamodromous specimens from the Lake Van basin in eastern Turkey were analyzed using two mitochondrial DNA markers. A. tarichi populations in the Lake Van basin are genetically heterogeneous, as indicated by the high haplotype and low nucleotide diversity of 1233 bp of the 16S rRNA marker (44 haplotypes; 70 polymorphic sites, haploid diversity (Hd ) = 0.9130, π = 0.0032) and 1140 bp of the cyt b marker (47 haplotypes; 82 polymorphic sites, Hd = 0.9339, π = 0.0057). Clades were separated by average sequence divergences of 1.94% (II vs. III), 1.80% (I vs. III), and 0.66% (I vs. II). Based on these clades, AMOVA analysis revealed that 80.76% of the total variation occurred among populations, 10.74% occurred within populations, and only 8.50% occurred between populations within groups for the concatenated 16S rRNA–cyt b sequences. Pairwise FST values varied from 0.0167 to 0.9705 for the concatenated 16S rRNA-cyt b dataset, emphasizing the high genetic variation among populations. The time since the endemic tarek populations split from their last common ancestor has been dated to 5.647 Ma (95% highest posterior density: 4.183–7.011 Ma) in the Messinian Stage. Recent population expansion for tarek populations has been determined by neutrality tests and mismatch distribution analyses. The results of this study provide valuable information on the genetic population structure, conservation, and management of this species.

Germ cell-specific expression of Venus by Tol2-mediated transgenesis in endangered endemic cyprinid Honmoroko (Gnathopogon caerulescens).

Fishes expressing a fluorescent protein in germ cells are useful to perform germ cell transfer experiments for conservation study. Nonetheless, no such fish has been generated in endangered endemic fishes. In this study, we tried to produce a fish expressing Venus fluorescent protein in germ cells using Honmoroko (Gnathopogon caerulescens), which is one of the threatened small cyprinid endemic to the ancient Lake Biwa in Japan. To achieve germ cell-specific expression of Venus, we used piwil1 (formally known as ziwi) promoter and Tol2 transposon system. Following the co-injection of the piwil1-Venus expression vector and the Tol2 transposase mRNA into fertilized eggs, presumptive transgenic fish were reared. At 7months of post-fertilization, about 19% (10/52) of the examined larvae showed Venus fluorescence in their gonad specifically. Immunohistological staining and in vitro spermatogenesis using gonads of the juvenile founder fish revealed that Venus expression was detected in spermatogonia and spermatocyte in male, and oogonia and stage I and II oocytes in female. These results indicate that the Tol2 transposon and zebrafish piwil1 promoter enabled gene transfer and germ cell-specific expression of Venus in G. caerulescens. In addition, in vitro culture of juvenile spermatogonia enables the rapid validation of temporal expression of transgene during spermatogenesis.

Successful breeding of the endemic cyprinid fish Dawkinsia rohani in controlled condition—First report

The present experiment was conducted to breed a vulnerable cyprinid fish, Dawkinsia rohani (Rohan's barb), in captivity through hormonal inducement using one of the reproductive synthetic hormones WOVA-FH, since these fish did not breed spontaneously in captivity. The experiment was conducted in 500-L capacity fibre-reinforced plastic tanks with breeding hapa. The male (length 8.5 ± 1.5 cm and weight of 12 ± 2 g) and female (length 9.5 ± 2 cm and weight of 15 ± 1.5 g) brooders were injected intramuscularly with variable dose of WOVA-FH and released into the breeding hapa at 2:1 (male:female) ratio. Varied doses of WOVA-FH used for fish in the present study refer to 0.3 ml/kg (T1), 0.5 ml/kg (T2), 0.7 ml/kg (T3), 1.0 ml/kg (T4) and 0.0 ml/kg T0 (control). General courtship behaviour was observed in hormone-induced fish after 6–9 h after injection. Breeding was observed in all the treatment group fish except T0 (control groups). Success of spawning, fertilization and hatching rate varied depending on the dose of hormone. Significantly higher fecundity (1142.3 ± 40.20 eggs/female), fertilization rate (90.2 ± 0.67%) and hatching rate (88.92 ± 0.25%) were achieved in fish injected with 0.7 ml/kg for female and 0.3 ml/kg for male per kg body weight compared to other hormone treatment groups. Dosage levels influence the percentage of spawning, egg stripping, fertilization and hatching rate. The present study successfully standardized the dose for induced breeding of D. rohani. The standardized breeding technology will be helpful in breeding, conservation and propagation of the endemic indigenous ornamental fish, D. rohani.

Optimization of fishway attraction flow based on endemic fish swimming performance and hydraulics

Attracting fish to fishway entrances is vital for ensuring successful and timely passage at dams and other in-stream barriers. This requires knowledge of both the target species' swimming ability and the hydrodynamics near the entrance. However, such knowledge is not always available during the initial design phase. The objective of this study is to propose suitable hydraulic conditions for the entrance of a fish passage facility to be built on the Jing River in China. We measured the swimming ability of three endemic cyprinid species (Phoxinus lagowskii, Triplophysa stoliczkae and Opsariich thysbidens) using three metrics: 1) induced flow velocity, 2) critical swimming speed, and 3) burst swimming speed. We then used a reduced-scale physical model of the fish passage facility and a verified 3D numerical hydrodynamic model to simulate the flow field under three fish collecting channel (FCC) operation scenarios. Connecting the fish swimming ability and the flow conditions in the river allowed to define the migration corridors present downstream of the FCC entrance under the different operation scenarios. Although the local velocity in the river near the fish passage entrance never exceeded the burst swimming speed of the target species, large backflow areas developed below the entrance in scenarios 1 and 2. The addition of a spur dike downstream of the entrance decreased the development of backflows, optimizing the width of the migration corridor by nearly 32%. This research presents a reliable and quantitative approach that combines fish swimming ability metrics and hydraulic characterization for optimizing attraction flows at fishway entrances.

Food and feeding habits of the endemic fish, Hypselobarbus thomassi (Day, 1874) in the Kallada River, Kerala, India

The feeding habits of the endemic cyprinid fish, Hypselobarbus thomassi (Day, 1874) was studied based on the monthly sampling in the Kallada River, Kerala, India from April 2010 to March 2011. Gut contents of 183 fish specimens were analysed and quantified using occurrence and volumetric methods. Analysis of the gut contents showed that semi-digested plant matter (22.11%) was the most preferred food item of the fish followed by Bacillariophyceae (19.80%), Chlorophyceae (19.38%), semi-digested animal matter (11.21%), soil particles (9.20%), seeds of plants (6.70%), Cyanophyceae (5.51%) and miscellaneous items (6.08%). The results indicated that H. thomassi is an omnivorous-stenophagic-column feeder. The gastrosomatic index (GaSI) ranged from 3.28-7.33 with an increment from August to November coincides with the spawning season and energy preservation for gonadal development. The information on feeding ecology of H. thomassi , a critically endangered fresh water fish from Western Ghats biodiversity hotspot would be useful towards formulating proper conservation plan for the species in its natural range.

Ecosystem approach applicability to sustain endemic fishes in Lake Laut Tawar, Aceh

Lake LautTawar is the only home for two endemic cyprinids, i.e. Rasboratawarensis and Poropuntiustawarensis, both are economically important species supporting food security and livelihood to local inhabitants. The present research was aimed to examine the applicability of EAFM, ecosystem approach to fisheries management in protecting endemic fishes in LLT. By referring to standard module, the domains and its indicators were ranked and weighted. Having given score to the domain, the composite domain and the sum of aggregation values of all domains, the performance of fishery management could be presented as flag model. Gap analysis was implied by contrasting EAFM’s recommendation against current achievement with refer to defined indicator. The applicability of EAFM to sustaining endemic fishes was assessed by means impact analysis under the scenario of three generic goals(1) augmenting the quality and quantity of habitat and sustainable utilization of fishery resources, (2) promoting higher socio-economic benefits, and (3) improving function and synergy among management institutions. The results showed that recommendations from EAFM’s model were all doable and that impact positively to sustaining endemic species. The challenges in implementation encompass authority, cooperation and coordination, stakeholders, invasive species and administration status of the lake.

Under the radar: genetic assessment of Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), two Rio Grande basin endemic cyprinids that have experienced recent range contractions

The Rio Grande drainage of the southwestern United States and Mexico has undergone intense anthropogenic alteration by water diversions, extraction and associated habitat changes. These alterations have disproportionately impacted the pelagic broadcast spawning guild of minnows (pelagophils). Several Rio Grande endemic pelagophils, including the co-occurring Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), have experienced dramatic recent range-wide declines yet have slipped under the radar of conservation efforts. The status of N. jemezanus and M. aestivalis in the Rio Grande and Pecos River was evaluated and standing genetic variation was characterized. Genetic evidence indicates that populations of both species found in the Rio Grande and Pecos River are genetically distinct. Additionally, 159 outlier loci were identified in M. aestivalis suggesting possible local adaptation in the Rio Grande and Pecos River populations. Though range-wide genetic data are limited, N. jemezanus populations in both rivers harbor considerable genetic diversity. Mitochondrial data from both taxa are consistent with a history of secondary contact between formerly isolated populations with deeply divergent haplotypes found within the Rio Grande and Pecos River populations of N. jemezanus and within the Rio Grande population of M. aestivalis. Extensive survey efforts in the lower Rio Grande and its tributaries in Texas document significant range contraction and near extirpation of N. jemezanus from this part of the basin; highlighting the need for immediate action to protect the species.

Diversity and phylogeny of Paradiplozoon species (Monogenea: Diplozoidae) parasitising endemic cyprinoids in the peri-Mediterranean area, with a description of three new Paradiplozoon species

The Diplozoidae are monogenean parasites of mainly cyprinoid fishes with a unique life cycle, whereby two larvae undergo anastomosis and fuse into a single cross-shaped specimen. Paradiplozoon is the most species rich and widespread genus of the family, with a distribution range covering Eurasia and Africa; however, some areas remain underexplored and their diplozoid fauna is uncertain. In the present study, the Paradiplozoon diversity was investigated in the peri-Mediterranean region, which has the highest levels of cyprinoid diversity and endemism in Europe. A total of 36 endemic cyprinoid species were sampled from sites in north-west Africa and the southern European peninsulas and investigated for the presence of diplozoid parasites. Of five Paradiplozoon species collected, three were identified as new to science: Paradiplozoon moroccoensis n. sp. from the Moroccan endemic Luciobarbus lepineyi; Paradiplozoon ibericus n. sp. from Iberian endemic cyprinids and leuciscids and Paradiplozoon helleni n. sp. from the Greek endemic Scardinius acarnicus and Tropidophoxinellus hellenicus (descriptions provided herein). In addition, new host records for P. homoion and P. megan are presented, with the former being most prevalent in the investigated region. Phylogenetic analysis supported paraphyly of the genus Paradiplozoon, and suggests the need for a careful taxonomic re-evaluation of this genus. Furthermore, the results showed that endemic Paradiplozoon of the peri-Mediterranean do not form a monophyletic group, suggesting multiple origins of this parasite groups in different peri-Mediterranean regions.

Toward the conservation of the endemic monotypic fish genus Aulopyge from the Balkan Dinaric karst: Integrative assessment of introduced and natural population.

The complex biogeographical history of the Balkan Peninsula caused remarkable freshwater fish diversity and endemism, among which Cyprinidae fish dominate. The Dinaric karst was a Pleistocene refugium and it harbors ancient and endemic cyprinids, including Aulopyge huegelii, a sole representative of its genus. Being highly distributionally restricted, it faces various threats that promote a critical decline in population abundance and even population extinction. Phenotypic and molecular diversity of the introduced (Šator Lake, Šator Mountain) and natural (Studena River, Duvanjsko Polje) populations of Dalmatian barbelgudgeon from Bosnia and Herzegovina was studied by using two mitochondrial genes and morphometric traits (linear and geometric morphometrics). Nonparametric ANOVA showed that two analyzed populations significantly differed in six linear measurements, except snout length and postorbital head length. Contrary to centroid size, two populations were found to be significantly different in body shape. Deformation grids indicated that individuals from Studena River are characterized by wider and slightly shorter body comparing to individuals from Šator Lake. Incongruence in cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b) mitochondrial DNA (mtDNA) variation was observed since a common COI haplotype was observed, while four and three cyt b haplotypes were registered in Šator Lake and Studena River, respectively. Since it was demonstrated that cyt b mtDNA was a faster evolving gene, we encourage its use in intraspecies studies, especially for evaluating the connectivity of fragmented populations and for studying the evolutionary footprint of the processes incorporated into the distinctive evolution of Aulopyge. Finally, findings herewith provide a firm basis for designing a long‐term sustainable conservation strategy for endemic species in Dinaric karst.

Population dynamics of Hypselobarbus thomassi (Day 1874), an endemic cyprinid fish from a tropical reservoir of Southern Western Ghats, India

AbstractThe Western Ghats of peninsular India is a highly sensitive and threatened ecoregion of exceptional freshwater ichthyodiversity. The present study investigated the growth, mortality and stock characteristics of Hypselobarbus thomassi, an endemic cyprinid fish from the Parappar Reservoir of Western Ghats, on the basis of the length‐frequency data collected during the period from 2009 to 2011. The growth parameters of this species were estimated using the FiSAT program, and the asymptotic length (L∞) and growth constant (K) being 476.79 mm and 0.39 year−1, respectively. The age at zero length (t0) was calculated as −0.0485 year−1. The longevity (tmax) and growth performance index (ϕ) were reported as 7.69 years and 2.95. The estimated total mortality (Z), natural mortality (M) and fishing mortality (F) were 1.65, 0.38 and 1.27 year−1, respectively. The relative yield per recruit (Y/R) analysis revealed the exploitation rate (E) at different levels as E0.1 = 0.36, E0.5 = 0.28 and Emax = 0.42. The current exploration level (0.77) is higher than the optimum exploitation rate (Emax = 0.42), indicating an overexploitation of the H. thomassi population. Accordingly, needed management measures should include restrictions on fishing gear mesh sizes, reduced fishing effort and declaration of closed seasons and sanctuaries to protect this threatened species.