Management Of Endangered Species Research Articles

Environmental (and random?) sex determination in endangered and invasive Phelsuma geckos.

Sex is a fundamental characteristic of an individual. It is therefore puzzling why in some systems sex is precisely determined by a genotype, while in others it is influenced by the environment or even subtle, not to say random, factors. Some stochasticity in sex determination would be expected if environmental conditions did not have a large sex-specific effect on fitness. Although data are only available for a small fraction of species, geckos show exceptional variability in sex determination. We tested the effects of three incubation temperatures on sex ratio and adult body size in the invasive gecko Phelsuma laticauda and the vulnerable gecko Phelsuma nigristriata. We document temperature-dependent sex determination (TSD) in both species. Only females hatched at a low temperature (24 °C), whereas male production peaked at an intermediate temperature (29 °C) and declined, at least in P. laticauda, again at the highest temperature (31 °C). Interestingly, full siblings hatched from eggs glued together during the incubation at temperatures producing both sexes are often of the opposite sex. We found no significant effect of incubation temperature on adult body length. Documentation of TSD in the day geckos has implications for conservation practice in environmental management of endangered species or eradication of invasive species. However, it appears that a very subtle (random?) factor may also be involved in their sex determination. In line with this, we found no significant effect of incubation temperature on adult body length, suggesting that, at least in this trait, there is no strong selection against producing females at "male" temperatures.

Management implications of habitat selection by whooping cranes (Grus americana) on the Texas coast

AbstractEffective habitat management for rare and endangered species requires a thorough understanding of their specific habitat requirements. Although machine learning models have been increasingly used in the analyses of habitat use by wildlife, the primary focus of these models has been on generating spatial predictions. In this study, we used machine learning models in combination with simulated management actions to guide planning and inform managers. We used data from 61 whooping cranes (Grus americana) tagged with GPS telemetry collars between 2009 and 2018 near Aransas National Wildlife Refuge in coastal Texas. We included variables based on topography, land use classification, vegetation height, plant phenology, drought, storm surge events, and both wild and prescribed fires. We then built models at multiple scales: population level, home range level, and roosting and daytime within home range level. We simulated responses to the two primary management actions used to enhance whooping crane habitat on Aransas National Wildlife Refuge: prescribed fire and removal of woody vegetation. At the population and home range scales, land use classification variables had the highest importance values, whereas the combined elevation and bathymetry layer was the most important predictor at both roosting and daytime within home range scales. Our findings revealed that the effects of fire, although generally modest, varied spatially. Areas dominated by estuarine wetlands exhibited higher predicted use within the first months after a fire, whereas those dominated by palustrine wetlands were more likely to be avoided in the immediate postfire years. Our simulation of vegetation removal identified the areas on Aransas National Wildlife Refuge where whooping cranes were predicted to benefit the most if vegetation were removed. These techniques can be used by other researchers wanting to examine and predict the effects of potential management actions on target species habitat.

First whole-genome sequence and assembly of the Ecuadorian brown-headed spider monkey (Ateles fusciceps fusciceps), a critically endangered species, using Oxford Nanopore Technologies.

The Ecuadorian brown-headed spider monkey (Ateles fusciceps fusciceps) is currently considered one of the most endangered primates in the world and is classified as critically endangered [International union for conservation of nature (IUCN)]. It faces multiple threats, the most significant one being habitat loss due to deforestation in western Ecuador. Genomic tools are keys for the management of endangered species, but this requires a reference genome, which until now was unavailable for A. f. fusciceps. The present study reports the first whole-genome sequence and assembly of A. f. fusciceps generated using Oxford Nanopore long reads. DNA was extracted from a subadult male, and libraries were prepared for sequencing following the Ligation Sequencing Kit SQK-LSK112 workflow. Sequencing was performed using a MinION Mk1C sequencer. The sequencing reads were processed to generate a genome assembly. Two different assemblers were used to obtain draft genomes using raw reads, of which the Flye assembly was found to be superior. The final assembly has a total length of 2.63 Gb and contains 3,861 contigs, with an N50 of 7,560,531 bp. The assembly was analyzed for annotation completeness based on primate ortholog prediction using a high-resolution database, and was found to be 84.3% complete, with a low number of duplicated genes indicating a precise assembly. The annotation of the assembly predicted 31,417 protein-coding genes, comparable with other mammal assemblies. A reference genome for this critically endangered species will allow researchers to gain insight into the genetics of its populations and thus aid conservation and management efforts of this vulnerable species.

Environmental DNA Detects Remaining Populations of Endangered Stream Salmon (Sichuan Taimen: Hucho bleekeri Kimura Salmonidae) in the Qinling Mountains

Sichuan taimen (Hucho bleekeri Salmonidae) populations are declining, and the status of remnant populations in the Qinling Mountains is poorly known. In this study, eDNA and creel netting were used to estimate the distributions of Sichuan taimen in two upper tributaries of the Hanjiang River. A qPCR assay was applied to detect the eDNA of H. bleekeri, and the presence of Sichuan taimen in the Taibai River, but not in the Xushui River, was confirmed. Sampling during summer achieved a relatively higher detection rate. The utility of eDNA techniques for detecting low-density Sichuan taimen was demonstrated in intricate stream ecosystems. The eDNA method can increase the efficiency of the management of endangered freshwater species, such as Sichuan taimen, by providing reliable distribution data.

A novel eDNA approach for rare species monitoring: Application of long-read shotgun sequencing to Lynx rufus soil pawprints

Environmental DNA (eDNA) sampling is a relatively new technique that has been employed in biodiversity surveys around the world. Environmental DNA can be an effective, non-invasive method of identifying the presence of target host species. Furthermore, advances in DNA deep sequencing technologies are enabling in-depth information to be recovered from eDNA. Here we report the development of a bobcat (Lynx rufus) species-specific probe-based qPCR assay for eDNA studies, which was validated on wild samples and those from a bobcat housed at the Jacksonville Zoo in Florida. Furthermore, we show that long-read shotgun sequencing of eDNA extracted from pawprint soil samples, using an Oxford Nanopore Technologies MinION, could successfully detect bobcat DNA, including enabling correct species level identification and phylogenetic placement within regionally distanced bobcats. This was all achieved without utilizing any DNA enrichment approaches. The long read shotgun sequencing simultaneously recovered genetic information from microbes known to be part of the bobcat microbiome, indicating that potential health-status-related microbial information can be obtained alongside wildlife eDNA. This study revealed that non-targeted (no metabarcoding or enrichment) long-read shotgun sequencing of eDNA samples can be sufficient for species identification, phylogenetic analyses, and population genetics applications. This paves the way for the rapid deployment of eDNA approaches for any species of interest, without requiring laborious development of targeted approaches, thereby increasing the ease and utility of eDNA research for endangered species conservation and management.

Reduction of genetic diversity in 'Alalā (Hawaiian crow; Corvus hawaiiensis) between the late 1800s and the late 1900s.

Genetic and genomic data are increasingly used to aid conservation management of endangered species by providing insights into evolutionary histories, factors associated with extinction risks, and potential for future adaptation. For the 'Alalā, or Hawaiian crow (Corvus hawaiiensis), genetic concerns include negative correlations between inbreeding and hatching success. However, it is unclear if low genetic diversity and inbreeding depression are consequences of a historical population bottleneck, or if 'Alalā had historically low genetic diversity that predated human influence, perhaps as a result of earlier declines or founding events. In this study, we applied a hybridization-based sequence capture to generate a genome-wide single nucleotide polymorphism (SNP) dataset for comparing historical specimens collected in the 1890s, when 'Alalā were more numerous, to samples taken between 1973 and 1998, when 'Alalā population densities were near the lowest documented levels in the wild, prior to all individuals being collected for captive rearing. We found low genome-wide diversity in both sample groups, however, the modern sample group (1973 to 1998 cohort) exhibited relatively fewer polymorphic alleles, a lower proportion of polymorphic loci, and lower observed heterozygosity, consistent with a population decline and potential bottleneck effects. These results combined with a current low population size highlight the importance of continued efforts by conservation managers to mitigate inbreeding and maintain founder representation to preserve what genetic diversity remains.

The International Legacy of the United States Endangered Species Act of 1973

December 2023 will mark the 50th anniversary of the passage of the 1973 Endangered Species Act of the United States. This landmark Act by the US Congress was made possible through strong bipartisan political cooperation on environment protection, capping off a string of progressive legislative victories that would set the tone for US environmental policy at local, state, and federal government levels for decades. Beyond its domestic significance, the 1973 Endangered Species Act had a clear and recognizable impact on global environmentalism by influencing and inspiring endangered species legislation in other nations as well as the 1992 Convention on Biological Diversity. At the time of its passage, the US Endangered Species Act (ESA) was far and away the most comprehensive piece of legislation ever enacted to halt and reverse rising rates of species extinction and biodiversity loss. Other nations emulated the ESA in past and present endangered species laws and regulations, even as late as 2019, leading to the eventual emergence of a set of global standard practices for species and habitat protections that endure to this day, practices with clear American roots. This study explores the degree to which the past and present endangered species laws of other English-speaking jurisdictions borrowed from or mimicked the US Endangered Species Act in purpose, style, form, and function. Further analysis is undertaken to reveal the extent to which Japan’s own endangered species protection statute is likely influenced by the US ESA. The ESA’s influence on global environmental norms and wildlife protection practices is first explored through the lens of international relations theory, in particular the ‘constructivist’ school of thought that helps explain recognized patterns in global environmental cooperation. The study demonstrates how the 1973 Endangered Species Act essentially became a template for other national and provincial governments to model and even mimic when these governments were designing and enacting their own endangered species management protection programs. Historically, the ESA’s passage and its emulation by other polities are indicative of the degree to which the United States has impacted and continues to greatly impact and influence global wildlife law and policy.

Agent-based diffusion in predation systems with Beddington–DeAngelis response

Understanding dynamical behavior of a spatially distributed population is crucial to conservation and management of endangered species. This paper considers predator–prey systems with Beddington–DeAngelis functional response, where the predator moves between source–sink patches asymmetrically and acts as an agent. Our aim is to show how agent-based diffusion affects dynamics of the system and total population abundance of the species. Using dynamical systems theory, we demonstrate stability of positive equilibria in the system, which implies coexistence of the species and change of abundance by diffusion. Moreover, we show Hopf and Bautin bifurcations with multiple limit cycles, which implies multiple oscillations of populations and even extinction of species. Furthermore, this work demonstrates that diffusion in the system may lead to results reversing those without diffusion. The diffusion could change dynamics of the system between coexistence at a steady state and persistence in periodic oscillation, while evolution in asymmetry of diffusion could make the predator reach a total abundance larger than that without diffusion, even reach the maximal abundance. Our results are consistent with experimental observations and are important in studying conservation of biodiversity.

Fitness consequences and ancestry loss in the Apennine brown bear after a simulated genetic rescue intervention.

Reduction in population size, with its predicted effects on population fitness, is the most alarming anthropogenic impact on endangered species. By introducing compatible individuals, genetic rescue (GR) is a promising but debated approach for reducing the genetic load unmasked by inbreeding and for restoring the fitness of declining populations. Although GR can improve genetic diversity and fitness, it can also produce loss of ancestry, hampering local adaptation, or replace with introduced variants the unique genetic pools evolved in endemic groups. We used forward genetic simulations based on empirical genomic data to assess fitness benefits and loss of ancestry risks of GR in the Apennine brown bear (Ursus arctos marsicanus). There are approximately 50 individuals of this isolated subspecies, and they have lower genetic diversity and higher inbreeding than other European brown bears, and GR has been suggested to reduce extinction risks. We compared 10 GR scenarios in which the number and genetic characteristics of migrants varied with a non-GR scenario of simple demographic increase due to nongenetic factors. The introduction of 5 individuals of higher fitness or lower levels of deleterious mutations than the target Apennine brown bear from a larger European brown bear population produced a rapid 10-20% increase in fitness in the subspecies and up to 22.4% loss of ancestry over 30 generations. Without a contemporary demographic increase, fitness started to decline again after a few generations. Doubling the population size without GR gradually increased fitness to a comparable level, but without losing ancestry, thus resulting in the best strategy for the Apennine brown bear conservation. Our results highlight the importance for management of endangered species of realistic forward simulations grounded in empirical whole-genome data.

Using Photo-ID to document and monitor the prevalence of fibropapilloma tumours in a foraging aggregation of green turtles

Sea turtle in-water monitoring has been conducted in Diani-Chale National Marine Reserve (DCMR) in Kenya’s South Coast since 2018, where green sea turtles (Chelonia mydas) may be found resting or foraging. Underwater surveys are conducted at a regular basis to collect data on sea turtle occurrence, abundance, and distribution, incorporating photographic identification (Photo-ID) as a capture-mark-recapture method. Photo-ID is a non-invasive, low-cost, citizen-science-friendly approach that allows researchers to obtain discrete information about individuals’ locations and health status at a given time, which is essential knowledge for spatial planning and conservation management of endangered species. When visible in the photos collected on a single individual, the occurrence of external tumours is noted, and the turtle is flagged for fibropapilloma (FP) monitoring. From July 2018 to December 2022, 2757 green turtle encounters were recorded, resulting in the identification of 571 individuals. External tumours were observed in 75 individuals. The temporal progression of the tumour’s growth was monitored through subsequent re-sightings of 47 of the affected individuals, with evidence of tumour progression and regression. Documenting the incidence of this disease on sea turtles usually involves the manipulation of captured animals, and is quite possibly under-documented in foraging grounds. Tracking the evolution of this disease using Photo-ID can be a useful, non-invasive method to understand its extent in foraging aggregations where turtles can be easily observed underwater.

Genomic and environmental insights and conservation challenges for two hybridizing iconic crocodile species across Mexico: Crocodylus acutus and C. moreletii

AbstractHybridization is of key relevance for conservation of wild species, and yet it is still one of the most controversial issues in conservation. Identifying historical and contemporary factors promoting the formation and maintenance of hybrids is crucial for the management of endangered species, as well as characterizing the environmental factors and patterns of habitat use among parental species and their hybrids. Crocodiles are a conservation priority group since all 23 species recognized worldwide are in a protected category and hybridization occurs between many of their species, particularly between Crocodylus acutus and C. moreletii. Their hybridization system encompasses a geographically extensive hybrid zone, where two distinct hybrids and two C. acutus lineages have diverged and only a few geographically isolated populations of both parental species remain. We used a combined approach of genome‐wide sequencing and ecological niche modeling to discern the geographic and temporal patterns of introgression, migration, and demography, and to assess the ecological niches of the distinct lineages. Our approach enabled us to determine the spatial and temporal components of the divergence and admixture events of hybrids and non‐admixed lineages, to describe the environmental characteristics and geographic extent of areas of sympatry, and to confirm human‐mediated hybridization events. Our findings also showed overall distinct ranges and ecological niches among lineages, where hybrids presented a different set of environmental requirements from both parental species. This approach can be readily applied to different taxa and ecological contexts, providing species information on genetics and the environment with direct conservation relevance. We additionally describe the various conservation challenges that C. acutus and C. moreletii currently face, highlighting that these distinct crocodile species and hybrid lineages warrant recognition and need urgent conservation effort.

Endangered flora in protected areas of Rio de Janeiro municipality – Rio de Janeiro State, Brazil

This study presents a qualitative analysis of endangered species occurrences in conservation units of Rio de Janeiro, one of the largest Brazilian municipalities in population size. Increasing human activities trigger changes in biodiversity, promote fragmentation, and reduce species distribution ranges, which can ultimately lead to declines in population sizes. One of the main goals of protected areas (PAs), such as conservation units, is to protect and conserve biodiversity. Here, we compiled all vascular plant species recorded within Rio de Janeiro PAs by consulting the Reference Center for Environmental Information (SpeciesLink), Flora do Brasil (2020), and primary data records contained in management plans. We compared this compilation with the list of Brazilian endangered plant species, verifying whether the management plans presented specific programs for these species. Of the 60 surveyed PAs, 24 had records of endangered species and only 17 had management plans, 14 of which had a specific program that contemplated the monitoring and/or conservation of endangered species. A total of 70 endangered species were recorded. The highest numbers of endangered species were found in the Tijuca National Park (41) and the Pedra Branca State Park (17), the two largest PAs with the two largest forest fragments. Despite the high number of endangered species and the number of protected areas that harbor them, few internal programs address endangered species conservation and management. Thus, efforts to maintain endangered species in protected areas can be aided by field data collections that confirm their occurrence and maintenance in these PAs.

Genetic markers separate breeding populations of the endangered Antipodean Albatross and allow for determination of provenance of birds killed at-sea

ABSTRACT Advances in technology and software have provided higher resolution of genetic data. Re-analysis of genetic data from the endangered Antipodean Albatross using STRUCTURE shows that samples from the two main breeding populations on Antipodes and Adams Islands can be assigned correctly to each population using a set of nine microsatellite markers. The new analyses allow for assignment of bycatch birds killed off the east coast of New Zealand with high accuracy and show all of them originated from Antipodes Island. This highlights not only the importance of using genetic markers to inform conservation and management of endangered species but also the important advances in bioinformatics and the value of existing datasets.

A synoptic review of the Amphibians of Iran: bibliography, taxonomy, synonymy, distribution, conservation status, and identification key to the eggs, larvae, and adults.

This study provides an illustrated account, a comprehensive update of the systematics, and a bibliography of the 15 species of anurans in five families, eight genera; and of the six species of urodeles in two families, four genera in Iran. Bufonidae, with eight species, is the most diverse family; Salamandridae has five species and Ranidae has four species. This study also presents updated identification keys for the eggs, larvae, and metamorphosed amphibians of Iran. We designated specimen NMW 19855.1 as neotype of Pelophylax persicus (Schneider, 1799) comb. nov.. Along with distribution maps obtained from all the reliable localities and museum specimens known at this time, the modelled habitat of species, and for the first time, the National Red List of amphibians based on the IUCN red list categories and criteria. Based on our evaluation we propose to categorize Bufo eichwaldi, Paradactylodon persicus, Neurergus derjugini, and N. kaiseri as Vulnerable at National Red List, and to move Bufotes (Calliopersa) luristanicus, B. (C.) surdus, Firouzophrynus olivaceus, and Rana pseudodalmatina from the category of Least Concern (LC) to Near Threatened (NT). The National Red List of amphibians that we propose has significant implications for endangered species management and conservation. Forty-one percent of amphibian species in Iran are endemic to the country, and more than forty percent of the Iranian amphibians are at risk of extinction. Zagros Mountain forest and Hyrcaniain forests have more than 80% (i.e. 18 species) of the diversity of Iranian amphibians. A considerable amount of scientific literature published on Iranian amphibians in Persian language is not easily accessible to researchers outside Iran. This monograph attempts to remedy the situation and provides broader access to international herpetology. We recognize that taxonomy is always in a state of flux, and the names and synonymies used here reflect our current view.

Conservation management in the context of unidentified and unmitigated threatening processes

The decision to intervene in endangered species management is often complicated. Migratory species exemplify this difficulty because they experience diverse threats at different times and places that can act cumulatively and synergistically on their populations. We use population viability analysis (PVA) to compare potential conservation interventions on the critically endangered, migratory Orange-bellied Parrot Neophema chrysogaster. This species suffers high juvenile mortality, but it is not clear why this is so. Given uncertainty about the best recovery strategy, we compare PVA scenarios that simulate various ways of utilizing captive-bred parrots to support the wild population in the context of unresolved threatening processes. Increasing the number of juveniles entering the population each year had the greatest benefit for population growth rate and size. Directly lowering juvenile mortality rates is difficult given uncertainty about the drivers of mortality in the wild. In lieu of this, releasing 100 juveniles from captivity to the wild population each autumn (either as a stand-alone action, or in combination with other interventions) was the most feasible and straightforward intervention of the options we tested. However, our PVAs also show that unless substantial and sustainable reductions can be made to juvenile mortality rates, Orange-bellied Parrots will remain dependent on intensive conservation management. This study highlights the utility of PVAs for answering practical questions about how to implement species conservation. PVAs provide a way to incorporate the best available information in a replicable modelling framework, and to identify impacts of parameter uncertainty on demographic trends.

Quercus insignis seedling response to climatic transfer distance in the face of climate change

Rising temperatures are causing increased tree mortality at lower elevations and upward migrations in montane tree communities. To reduce the risk of extinction from climate change, managed translocation or assisted migration could serve to support the management of endangered species, but is currently a controversial strategy with very limited information available from experimental field studies in the tropics. We examined the effect of climatic transfer distance (CTD; the climatic difference between the site of seed origin and the site of plantation) on the establishment of Quercus insignis, an endangered oak with a distribution restricted to cloud forests. If the natural population (seed origin) occurs at its optimum climate, a decline in seedling transplant performance is expected to occur with greater CTD. Enrichment plantings were established in three sites near the seed origin area (at 1400 m a.s.l.), and in five sites from an elevation similar to the seed source up to high elevations (1365 to 2531 m a.s.l.) in Mexico. We examined the effect of CTD on seedling survival and Relative Growth Rate (RGR) over a period of four years. In the provenance area, a 1.4 °C increase and a 25–30 % annual precipitation decrease were estimated to have occurred during the study period (2018–2021), relative to the reference climate (1960–1990) in which the population in the provenance area developed. We found no significant evidence to support lower seedling survival with greater CTD. High survival occurred in sites with a warmer temperature at present (up to 80 % survival), but also in colder sites at higher elevation (up to 90 %), revealing the high tolerance of Q. insignis to a wide range of climatic conditions. The RGR showed the expected decrease with greater CTD of the Aridity Index, reflecting the importance of the balance between temperature and water availability. These findings support the potential of Q. insignis enrichment plantings, both near the seed origin area and at higher elevation (currently 2–3 °C colder than in the provenance area) to compensate for the expected temperature increase. However, the projected reduction in precipitation and cloud immersion within the cloud forest belt associated with climate change, could act to limit growth and lead to lower establishment success.

Automated detection of dolphin whistles with convolutional networks and transfer learning.

Effective conservation of maritime environments and wildlife management of endangered species require the implementation of efficient, accurate and scalable solutions for environmental monitoring. Ecoacoustics offers the advantages of non-invasive, long-duration sampling of environmental sounds and has the potential to become the reference tool for biodiversity surveying. However, the analysis and interpretation of acoustic data is a time-consuming process that often requires a great amount of human supervision. This issue might be tackled by exploiting modern techniques for automatic audio signal analysis, which have recently achieved impressive performance thanks to the advances in deep learning research. In this paper we show that convolutional neural networks can indeed significantly outperform traditional automatic methods in a challenging detection task: identification of dolphin whistles from underwater audio recordings. The proposed system can detect signals even in the presence of ambient noise, at the same time consistently reducing the likelihood of producing false positives and false negatives. Our results further support the adoption of artificial intelligence technology to improve the automatic monitoring of marine ecosystems.

Comparing trap and bait efficiency to record the great crested newts (Triturus cristatus)

A crucial aspect of conservation management for endangered newt species is the establishment of a monitoring methodology and the evaluation of trap efficacy to ensure the accuracy of data collection. In this study, we assessed three funnel trap types (prism shape, umbrella shape, and Ortmann's trap) to capture great crested newts (Triturus cristatus). We also tested three baits (chicken liver, chemical lights in glow sticks, and control traps without bait) and determined the optimal trap control time within a 12 h period. Our findings showed that the umbrella shape trap was most effective, catching five times more newts than the Ortmann's and prism shape traps. Surprisingly, the commonly used prism shape trap performed poorly. Bait type did not significantly impact newt captures compared to control traps. During the 12 h experiment, newts spent the longest time in the chicken liver-baited Ortmann's trap (averaging 4.5 h), while the umbrella shape trap with chicken liver bait had the highest turnover of individuals. We observed no behavioural response from “trap-shy” individuals. This study emphasizes the importance of selecting appropriate traps, considering bait choice, and trap control time for effective monitoring of endangered newt populations.

A meta‐analysis and model comparison of juvenile salmon growth across different habitat types

AbstractThe size of an organism is an important factor for a variety of physiological and ecological processes. For fishes, larger size can increase long‐term survival and provide a population level benefit. Therefore, threatened and endangered species management often focuses on supporting high quality habitat that provides growth opportunities. There are numerous habitat characteristics that can affect growth, including food availability, temperature, and habitat complexity. Understanding how growth responds to habitat types of different quality is the first step in determining what could lead to increased growth and potentially increased individual survival. We use Bayesian techniques to determine which of the differing methods is best for modeling the effects of habitat type and temperature on growth. To apply this method, we gather data from previous studies of the growth benefits of differing habitats and temperature regimes on Chinook salmon on the Sacramento River, CA, USA. We find a consistent growth benefit of floodplain rearing across multiple studies and show that a Ratkowsky model is the best for modeling this growth data. This information can specifically help managers model and protect the endangered and threatened Chinook populations in this system and more generally understand fish growth across differing habitat types.

Distribution Pattern and Brood Parasitism Characteristics of an Endangered Fish, Pseudopungtungia nigra, in the Geum River Basin, South Korea

Pseudopungtungia nigra is an endangered fish species endemic to South Korea with a narrow habitat range in the Geum River basin. Understanding their long-term distribution (25 years, 1997–2021) and breeding characteristics can contribute to the conservation and habitat management of endangered species in this area. We analyzed long-term data on environmental factors and fish in the Geum River and investigated the invading and spawning characteristics of P. nigra using underwater cameras. From the study results, P. nigra indicated no clear dispersion or decline trend in the Geum River. P. nigra exhibits brood parasitic behavior in the nest of Coreoperca herzi, another species found in the same region. C. herzi males protect their nests during the spawning period, and the eggs spawned by P. nigra in the nests of C. herzi are also protected by C. herzi. This high dependency of P. nigra on C. herzi possibly contributed to its distribution range in the Geum River basin. Habitat changes caused by anthropogenic interventions during the study period did not significantly affect the distribution of P. nigra. The results indicate that the distribution pattern of P. nigra is influenced by the distribution of sympatric fish species rather than environmental changes.