The review examined 227 publications on snakes of Bangladesh published from 1853 through 2024. These comprised 190 research articles, 31 books or book chapters, two conference proceedings and four institutional reports. Earlier country checklists reported differing totals, ranging from 28 species in 1980 to 106 in a 2015 field guide, creating inconsistencies in the documented snake fauna.

To assess occurrence and distribution, the researchers combined the literature with records from the Reptile Database, the IUCN Red List of Threatened Species in Bangladesh, GBIF, iNaturalist, the IUCN portal, and DNA-sequencing data in NCBI. They also searched electronic, print and social media for occurrence information. Social-media records were included only after the associated photographs and locations were checked individually, with Facebook-based groups led by academics and focused on snake rescue, public awareness and conservation prioritized among the sources.

The assembled records were divided into four categories: confirmed, regionally extinct, deleted and expected. A species was classified as confirmed when supported by a specimen-based literature record, research-grade repository data, or photographic documentation with cross-verified identification and locality. Species without documentation or confirmed sightings during the previous five decades were classified as regionally extinct, a designation that reflects the absence of records rather than demonstrated biological extinction. The remaining categories comprised species removed because of misidentification or taxonomic revision and species considered potentially present based on their ecological and geographical ranges.

Three species fell into the review’s regionally extinct category: the marine file snake, Acrochordus granulatus; the Kerala mud snake, Dieurostus dussumieri; and the Indian egg-eating snake, Boiga westermanni. The most recent documented sighting of A. granulatus was in the Sundarbans in 1970. The holotype of D. dussumieri was collected from “Bengal” but was lost or destroyed during World War II, while the holotype of B. westermanni was collected from Rangpur in 1863, with no subsequent confirmed Bangladeshi record documented by the review.

Sixteen species were deleted from the national list. Nine had appeared without specimen-based records or confirmed sightings, including the saw-scaled viper, Echis carinatus, and the mangrove pit viper, Trimeresurus purpureomaculatus. Taxonomic changes also affected several entries. The white-lipped green pit viper, Trimeresurus albolabris, is no longer expected on the Indian subcontinent; the long-nosed vine snake, Ahaetulla nasuta, is considered endemic to Sri Lanka; and a population formerly identified as Dendrelaphis pictus was reassigned to D. proarchos. The former subspecies Rhabdophis subminiatus helleri was elevated to species status as Rhabdophis helleri.

Among the 89 confirmed species, non-venomous snakes represented 70% and venomous species 30%. Colubridae was the largest family, accounting for 35% of confirmed species, followed by Elapidae at 25.8% and Natricidae at 13.5%. Typhlopidae and Homalopsidae each contributed 5.6%, while Pythonidae and Viperidae each represented 3.4%. The venomous assemblage included 23 elapids—10 terrestrial species and 13 marine hydrophiines—and three vipers. Rhabdophis helleri was the only confirmed species classified as both venomous and poisonous.

The researchers mapped species richness by aggregating occurrence data into a 0.02-degree grid within Bangladesh’s administrative boundary and counting unique species in each cell before applying a Gaussian filter. They separately used non-parametric kernel density estimation to create continuous probability surfaces for all confirmed species, non-venomous species and venomous species. The analysis used 1,768 observations for all species, including 1,322 for non-venomous snakes and 443 for venomous snakes.

The mapped estimates indicated the highest species richness in mixed evergreen forests in the Chattogram and Sylhet regions and in the Sundarbans mangroves, with moderate richness in central, northern and northwestern areas. Kernel density estimates placed the greatest probability of occurrence above 0.2 to 0.3 in the southeastern and northeastern mixed evergreen forests; estimates for non-venomous species exceeded 0.3 in those regions, while the northern region had an overall estimate below 0.1. Coastal southeastern Bangladesh showed high estimated potential for marine venomous species. These are occurrence-probability estimates derived from available records, not direct population measurements, and the review’s reliance on heterogeneous literature, repositories, social media and museum data limits precision.

The authors identified the mixed evergreen forests of southeastern and northeastern Bangladesh, the Sundarbans mangroves, east-central deciduous forests and northwestern low-plain wetlands as important habitats for the documented fauna. They also highlighted the vulnerability of these landscapes, including habitat destruction in the eastern forests and pressures from fishing, trawling, vehicle traffic, habitat loss and natural calamities in coastal areas. The taxonomy-focused inventory provides a revised baseline for conservation planning, while the 33 anticipated species remain unconfirmed and require specimen-based or otherwise verified evidence before inclusion among the country’s confirmed fauna.

Subject of Research: Systematic review of snake species diversity, occurrence and distribution patterns in Bangladesh

Article Title: Revisiting the snakes of Bangladesh: a systematic review of species diversity and distribution patterns

Article References: Haidar, I. K. A., Hasan, N., Islam, M. R., Uddin, M. A., Uddin, H., Hasan, M. T., Ullah, M. H., Jahan, N., Biswas, J. K., & Chowdhury, M. A. W. (2025). Revisiting the snakes of Bangladesh: a systematic review of species diversity and distribution patterns. Herpetozoa, 38, 253-269. https://doi.org/10.3897/herpetozoa.38.e163473

Image Credits: AI Generated

DOI: 10.3897/herpetozoa.38.e163473

Keywords: Bangladesh, snake diversity, systematic review, species richness, geographic distribution, taxonomic revision, habitat conservation, venomous snakes, occurrence records, Revisiting, snakes, systematic

The rediscovery was made during a five-day visit to São Nicolau from 23 to 28 January 2023. The authors combined direct observations and specimen collection with distribution mapping and a preliminary assessment under International Union for Conservation of Nature criteria. Specimens were identified using Donskoff’s original 1982 description, and the taxonomy followed the Orthoptera Species File. Mounted specimens were measured with digital calipers accurate to 0.01 mm.

Adults and nymphs were observed at sites on northeastern, southeastern and north-facing slopes at elevations from 650 to 1,100 metres above sea level. The records included locations around Monte Cintinha, Assomada Pass, the road between Tarrafal and Cachaço, and higher parts of Monte Gordo. The species appeared to be restricted to the northern half of the natural park and immediately adjacent areas, although densities seemed low.

All confirmed locations contained the native plant Euphorbia tuckeyana, but the vegetation ranged from open scrub and grassland to denser stands of introduced Pinus, Eucalyptus and Cupressus. Adults were generally found on the ground, including among rocks and in Arundo donax vegetation, while small nymphs occurred on Asteriscus smithii. The first specimens of the 2023 survey were detected at night; later sightings were made during the day, although some individuals may have been disturbed before they were observed.

The paper provides the first description of the female, which was based on two adult specimens. Females measured 28.8–33.4 mm in total length, compared with an average of 19.0 mm for the six measured males, including the holotype. Diagnostic characters included the shape of the pronotum, female antennae and ovipositor, and the form of the terminal abdominal structures. The study also redescribed the male and translated the original French description of the genus and species.

Measurements of the male holotype and five additional males, together with two females, showed substantial sexual dimorphism. Mean body length from the frons to the subgenital plate was 19.0 mm in males and 31.1 mm in females. Mean hind-femur length was 13.3 mm in males and 20.8 mm in females, while mean pronotum length was 4.6 mm and 8.7 mm, respectively. The authors noted that the observed males varied in colour and patterning, including the width and continuity of the dark longitudinal band on the pronotum.

For the preliminary Red List assessment, the area of occupancy was calculated by summing occupied 2 × 2 km grid cells. The lower extent of occurrence was based on the minimum convex hull around confirmed records, while the upper extent incorporated the authors’ estimate of the possible geographical range. The known area of occupancy was approximately 12 km², the lower extent of occurrence was 4 km², and the maximum estimated extent was 35 km². The polygon representing the estimated possible range also covered 12 km².

Because information on population size, trends and quantitative population change was unavailable, the assessment could apply only the geographic criteria B and D2. Entering the geographic estimates and threat information into the IUCN Species Information Service produced a proposed category of Vulnerable under criterion D2, reflecting the restricted area of occupancy and the small number of known sites. This was a data-limited assessment rather than a direct measurement of population decline.

The study identifies habitat alteration, introduced vegetation, grazing, fires, erosion and tropical storms among the pressures affecting the highland environment occupied by the grasshopper. It reports that Monte Gordo Natural Park retains fragments of native vegetation but also contains extensive 20th-century plantations of introduced trees. The authors note that the grasshopper’s persistence in degraded, introduced-plant-dominated habitats indicates some resilience, while emphasizing that its population size, precise range, ecology and responses to threats remain unresolved. The rediscovery therefore confirms that the species survives while leaving substantial gaps in the evidence needed to understand its population and conservation requirements.

Subject of Research: Field rediscovery, distribution and preliminary Red List assessment of the São Nicolau endemic grasshopper Eyprepocprifas insularis

Article Title: Rediscovery of the Monte Gordo Grasshopper Eyprepocprifas insularis : An ancient brachypterous species endemic to São Nicolau, Cape Verde ( Orthoptera , Eyprepocnemidinae )

Article References: Felix, R., Jacobs, A., & Lecoq, M. (2025). Rediscovery of the Monte Gordo Grasshopper Eyprepocprifas insularis: An ancient brachypterous species endemic to São Nicolau, Cape Verde (Orthoptera, Eyprepocnemidinae). Journal of Orthoptera Research, 34(2), 159-168. https://doi.org/10.3897/jor.34.144016

Image Credits: AI Generated

DOI: 10.3897/jor.34.144016

Keywords: Eyprepocprifas insularis, São Nicolau, Cape Verde, grasshopper rediscovery, Monte Gordo Natural Park, field survey, IUCN Red List, Orthoptera, endemic species, habitat conservation, Rediscovery, Monte

Native grasslands in the southeastern United States have lost an estimated 90% of their former range, according to the study’s introduction, and the remaining Virginia Piedmont fragments face habitat loss, fragmentation, altered disturbance regimes, invasive species and climate-related changes. Many surviving sites persist as semi-natural communities maintained by disturbance such as grazing or mowing, which limits shading by woody vegetation. The authors said the remaining grasslands can include some of the most endemic-species-rich habitats in eastern North America.

Researchers located potential fragments through satellite-image inspection, structured driving surveys and consultations with regional botanical experts. They selected 132 species-rich sites dominated by native heliophytic plants to establish a reference state for conservation and restoration. Sampling excluded actively hayed or grazed sites, sites known to have been planted with native wildflower seed and sites containing non-native species indicative of commercial meadow-seed mixtures.

Each site was sampled with one to three 100-square-metre plots, generally without adult trees, during June through November. Investigators recorded woody and herbaceous plants to the lowest practical taxonomic level and estimated species cover. Surveys were conducted in the northern Piedmont in 2020 and the central Piedmont in 2021. Soil samples combining at least five cores per site were analyzed for properties including pH, nutrients, organic matter, cation exchange capacity, estimated nitrogen release and bulk density.

The researchers recorded 604 native taxa, representing 86.9% of the total; 66 introduced taxa, or 9.5%; 20 invasive taxa, or 2.9%; and five taxa of uncertain status in Virginia, or 0.7%. Only 23 taxa occurred at half or more of the 132 sites, while 518 occurred at 10% or fewer, indicating substantial variation among communities. Six plots contained at least 100 species, and the most species-rich plot contained 114, including 103 native species. The surveys also found 13 state- or globally rare species, including the globally imperiled Torrey’s mountain-mint and basil mountain-mint.

Cluster analysis of 129 sites separated the grasslands into four compositionally distinct groups, with the overall group difference supported by PERMANOVA at P < 0.001 and R² = 0.19. Northern Prairie included 36 sites, Central Prairie 50, Savanna/Woodland 32 and Wet Grassland 11. Average species richness per 100-square-metre plot was 61.22 ± 2.18 for Northern Prairie, 67.49 ± 2.07 for Central Prairie, 74.25 ± 3.56 for Savanna/Woodland and 67.55 ± 4.65 for Wet Grassland, where values are mean ± standard error.

Indicator species further distinguished the groups. Indiangrass, Bush’s sedge and early bluegrass were among the five strongest indicators for Northern Prairie, while blue sedge, Elliott’s bluestem and splitbeard bluestem characterized Central Prairie. Savanna/Woodland had the highest average woody cover, 0.30 ± 0.02, and included pignut hickory, black cherry and black oak among its leading indicators. Wet Grassland was marked by wet-soil-associated plants, including common boneset, branched panicgrass, common rush, shallow sedge and arrowleaf tearthumb.

A three-axis non-metric multidimensional scaling ordination separated the communities along several measured environmental gradients. Northern Prairie was associated with higher soil manganese content. Savanna/Woodland was associated with higher soil organic matter, elevation and woody cover, as well as steeper slopes and upland topographic positions. Wet Grassland was associated with higher soil iron and graminoid cover and occupied low-lying positions. Central Prairie had intermediate species composition relative to the other groups. The ordination had a stress value of 0.16, a non-metric fit R² of 0.98 and a linear fit R² of 0.87.

The findings remain bounded by the study design. The researchers deliberately sampled the highest-quality fragments they could find, many of which were powerline corridors, old fields and roadside rights-of-way, rather than a representative sample of all Piedmont grasslands. Actively hayed, grazed and planted sites were excluded, and the origins and antiquity of many fragments could not be determined. Three statistical outliers were excluded from multivariate analyses, while 19 sites with missing environmental data were omitted from related analyses. The authors also reported observed losses during the study, including a rare stiff goldenrod population sprayed with herbicide and a Torrey’s mountain-mint population eliminated by sidewalk construction.

Overall, the study identifies at least four broad community groups within the surveyed northern and central Virginia Piedmont and provides measurable floristic and environmental distinctions that can inform future formal vegetation descriptions, conservation and restoration. The researchers described these as provisional groups for a region whose native grasslands remain understudied, fragmented and poorly protected, and said the full Piedmont would require additional survey and documentation.

Subject of Research: Floristic diversity and community types in selected northern and central Virginia Piedmont grasslands

Article Title: Floristics of Virginia’s Northern and Central Piedmont grasslands

Article References: Coscia, J. T., Harris, J. B. C., Floyd, D., Beall, M. C., Bellangue, D., Chaney, D., Gorrell, J., Sackett, E., Staengl, E. J., & Reid, J. L. (2024). Floristics of Virginia’s Northern and Central Piedmont grasslands. Vegetation Classification and Survey, 5, 267-278. https://doi.org/10.3897/vcs.126066

Image Credits: AI Generated

DOI: 10.3897/VCS.126066

Keywords: Virginia Piedmont, native grasslands, floristic diversity, vegetation classification, plant communities, soil ecology, rare plants, habitat conservation, field survey, Floristics, Virginia, Northern

The grasslands in question are of outstanding importance both scientifically and for conservation. Because they are low-productivity ecosystems, they resist domination by a few vigorous species and instead support an extraordinary diversity of plants, often dozens of species packed into a single square metre. Yet these formerly widespread habitats are in steep decline throughout Europe, losing both area and quality mainly through agricultural intensification, abandonment of traditional mowing and grazing, and eutrophication from airborne nutrients. The European Red List of Habitats recognises them as semi-dry perennial calcareous grassland, and the refined EUNIS habitat typology places them in category R1A, the semi-dry perennial calcareous grasslands and meadow steppes. A stable name for the order that unites these vegetation types is therefore not an academic nicety but a practical tool for conservation planning, habitat mapping and legal protection.

The scientific problem is rooted in the history of vegetation science itself. Phytosociology, the discipline that classifies plant communities, follows its own rulebook, the International Code of Phytosociological Nomenclature, currently in its fourth edition. Under this code, names of vegetation units are tied to nomenclatural types, typically a characteristic association or alliance, and priority rules determine which name is correct. For most of the twentieth century, the class Festuco-Brometea, which encompasses Europe’s dry and semi-dry grasslands, was divided into geographically defined orders. The order Brometalia erecti, described by W. Koch in 1926 from the Linth Plain on the Swiss Plateau, covered the subatlantic west, while the continental east was assigned to Festucetalia valesiacae, and further geographic orders such as Scorzoneretalia villosae and Helictotricho-Stipetalia were added for the more distal parts of the continent.

Koch’s original concept, however, differed from the way his name came to be used. In his 1926 publication, the alliance Bromion erecti was established with the association Mesobrometum erecti as its holotype, and the order Brometalia erecti was established with Bromion erecti as its holotype. The Mesobrometum erecti clearly belongs to the subatlantic, mesoxeric basiphilous grasslands. In the following decades, though, the concept of Brometalia erecti was narrowed to the subatlantic parts of the class, and in some influential treatments the order was even applied in a sense that excluded its own type, comprising only the xeric Xerobromion. This history of shifting and contradictory usage is precisely why many modern authors regard Brometalia erecti as a nomen ambiguum, an ambiguous name whose continued use invites confusion.

The turning point came from two mid-century botanists. Krausch in 1961 first highlighted that the mesoxeric alliances of the two geographic orders, the Mesobromion erecti and the Cirsio-Brachypodion pinnati, share more floristic commonalities with each other than with their respective xeric counterparts, the Xerobromion erecti and the Festucion valesiacae. Korneck then took the decisive step in 1974, proposing to replace the purely geographic division of the class with a mainly edaphic one, based on soil conditions, and establishing the order Brachypodietalia pinnati to unite the mesoxeric grasslands. His order comprised the alliances Cirsio-Brachypodion pinnati and Mesobromion erecti. Subsequent large-scale analyses, notably by Willner and colleagues in 2017 and 2019 using extensive datasets from Central and Eastern Europe, confirmed that three main subtypes of the class can be distinguished by soil conditions: mesoxeric, xeric and rocky. The mesoxeric order concept has since been adopted in major syntheses including the EuroVegChecklist of Mucina and colleagues in 2016.

Here the nomenclatural complication deepens. Under the code’s priority rules, Korneck’s name Brachypodietalia pinnati is technically a nomen superfluum, a superfluous name, because his original diagnosis included the type of the earlier-published Brometalia erecti. A superfluous name automatically receives the type of the name it should have replaced, meaning that under strict application of the rules the correct name for the mesoxeric order would be Brometalia erecti W. Koch 1926. But because that name has been applied to at least two vastly different concepts, a geographic order spanning mesoxeric and xeric grasslands, and in some usages a xeric-only order excluding its own type, adopting it for the modern mesoxeric order would sow confusion rather than resolve it. Dengler and colleagues had already chosen the alliance Cirsio-Brachypodion pinnati as the lectotype of Brachypodietalia pinnati in 2003, and numerous authors across Europe have explicitly used the name as a proposed conserved name, but the formal step of submitting a proposal under the code had never been taken until now.

The new proposal therefore asks the Group for Phytosociological Nomenclature to conserve Brachypodietalia pinnati Korneck 1974 against the earlier names Brometalia erecti W. Koch 1926 and Scorzoneretalia villosae Kovačević 1959, and to do so with a conserved type, the alliance Cirsio-Brachypodion pinnati Hadač & Klika in Klika and Hadač 1944. The authors draw an explicit analogy with an earlier successful case, the conservation of the alliance name Mesobromion erecti against the earlier Bromion erecti, argued by Terzi and colleagues in 2016 and ruled on by Theurillat and colleagues in 2017. The Scorzoneretalia villosae, typified by the Scorzonerion villosae, is included among the names to be rejected because it has never been used for a pan-European mesoxeric order, and the current broad order concept comprises five xeric or rocky orders alongside the single mesoxeric one.

Carefully, the authors have framed the proposal so that it constrains only the mesoxeric usage. They deliberately refrain from proposing Brometalia erecti as a nomen ambiguum, keeping that name and others available for researchers who prefer the traditional concept of purely geographically delimited orders. If the proposal is accepted, an order comprising the alliances Bromion erecti and Xerobromion, but not the Cirsio-Brachypodion, would still legitimately be called Brometalia erecti. An order combining the Festucion valesiacae with the Cirsio-Brachypodion, but lacking the Bromion erecti, would bear the name Festucetalia valesiacae, since that name has priority over Brachypodietalia pinnati. And an order containing the Scorzonerion villosae and Saturejion subspicatae without the two core mesoxeric alliances would continue to be called Scorzoneretalia villosae. In other words, the conserved name could only be used when referring to a purely mesoxeric order, while dissenting authors would face no change to their own practice.

The precise boundaries of the mesoxeric order remain an open research question, and the authors are candid about this. A pan-European synthesis based on vegetation plots from the European Vegetation Archive is still pending, so it is not yet fully resolved which alliances belong to the order. The consensus core, according to the EuroVegChecklist, includes the Bromion erecti, Cirsio-Brachypodion pinnati, Filipendulo vulgaris-Helictotrichion pratensis, Gentianello amarellae-Helictotrichion pratensis, Potentillo montanae-Brachypodion pinnati, Polygalo mediterraneae-Bromion erecti and Chrysopogono-Danthonion calycinae. Recent analyses by García-Mijangos and colleagues in 2021 supported adding the Potentillo montanae-Brachypodion pinnati and much of the Iberian Brachypodion phoenicoidis, demonstrating that two Spanish associations previously assigned to other classes and orders in fact belong to the Brachypodietalia pinnati. The position of the French type association of the Brachypodion phoenicoidis, however, remains less clear, and the authors deliberately excluded that order from their proposal until a large-scale plot-based classification can settle the question.

Whether the Group for Phytosociological Nomenclature accepts the proposal will determine the official name attached to some of the most species-rich plant communities on Earth. The authors argue that acceptance would support nomenclatural stability while avoiding the confusion caused by identical names applying to vastly different concepts, and that the time is ripe for a formal decision. For the scientists who survey, map and defend Europe’s semi-dry calcareous grasslands, a settled name would mean that habitat assessments, red-list evaluations and cross-border conservation strategies all rest on a shared, unambiguous vocabulary. In a field where a single name can carry half a century of shifting meanings, the conservation of Brachypodietalia pinnati would be a quiet victory for clarity, achieved not in the field with a quadrat and a species list, but in the pages of a nomenclatural proposal.

Subject of Research: Nomenclatural conservation of the grassland order name Brachypodietalia pinnati within the class Festuco-Brometea

Article Title: Proposal (31) to conserve the name Brachypodietalia pinnati Korneck 1974 as a nomen conservandum with a conserved type

Article References: Dengler, J., & Willner, W. (2023). Proposal (31) to conserve the name Brachypodietalia pinnati Korneck 1974 as a nomen conservandum with a conserved type. Vegetation Classification and Survey, 4, 63-68. https://doi.org/10.3897/vcs.100985

Image Credits: AI Generated

DOI: 10.3897/VCS.100985

Keywords: Brachypodietalia pinnati, Festuco-Brometea, phytosociological nomenclature, nomen conservandum, mesoxeric grasslands, calcareous grassland, Brometalia erecti, vegetation classification, biodiversity, habitat conservation, Cirsio-Brachypodion pinnati, International Code of Phytosociological Nomenclature

The special issue brings together selected papers from the international conference “The Fish of Muddy Waters,” which took place in Vienna, Austria, in October 2025. The event gathered researchers and conservation practitioners around a shared theme: fish species adapted to the specific and often extreme conditions of wetlands and their surrounding areas. By compiling the conference’s findings in a peer-reviewed format, the editors aim to make results that might otherwise remain scattered across national reports and conference presentations accessible to an international audience of experts, and to consolidate a body of knowledge that has long been fragmented.

Among the species at the heart of the issue are the European mud minnow (Umbra krameri), the weatherfish (Misgurnus fossilis), and the crucian carp (Carassius carassius). Each of these fish represents a distinct evolutionary answer to the same fundamental problem: how to survive in water that other fish cannot tolerate. The weatherfish, for example, is famous among ichthyologists for its ability to supplement its oxygen uptake by swallowing air at the surface, an adaptation that allows it to persist in stagnant, silt-laden ponds where oxygen levels can collapse. The mud minnow similarly tolerates low-oxygen environments, while the crucian carp is renowned for its extreme physiological tolerance of anoxic conditions, particularly in small water bodies that freeze over in winter.

These adaptations are more than biological curiosities. Because the fish that inhabit small, muddy wetlands live at the very edge of what is physiologically possible, they are acutely sensitive to changes in their environment. Alterations to hydrology, pollution, the loss of temporary floodplain pools, or the arrival of new competitors can push populations past critical thresholds. This sensitivity gives these species a second, less obvious role: they can serve as indicators of the ecological health of their habitats. If specialised wetland fish are struggling, the signal often points to broader changes or a deterioration in the entire ecosystem, long before the damage becomes visible in more conspicuous elements of the landscape.

This indicator function was a central theme of the Vienna conference. Organisers deliberately sought to strengthen the link between research and conservation practice, and to draw public attention to fish species that typically receive far less attention than larger, more commercially valuable, or more photogenic aquatic animals. Salmon, trout, and sturgeon dominate the public imagination and much of the conservation funding landscape, while the mud-dwelling specialists of floodplain pools and marsh ditches remain largely invisible. The conference and the resulting special issue argue that this imbalance leaves a critical gap in Europe’s biodiversity strategy, because the species most tightly bound to wetland habitats are also among the first to disappear when those habitats degrade.

The issue also confronts a growing pressure on these systems: non-native fish species that have become established in the peripheral areas of floodplains and other wetland habitats. Contributions examine which introduced species have gained a foothold in these environments and discuss their impact on native ecosystems. Invasive fish can alter wetland communities through predation, competition for food and spawning sites, and the modification of habitat structure, and their tolerance of degraded conditions can allow them to thrive precisely where native specialists are already stressed. Understanding these interactions is essential for conservation managers who must decide where and how to intervene in modified floodplain landscapes.

The broader context for this work is sobering. European wetlands are among the continent’s most heavily altered ecosystems, having been drained for agriculture, cut off from rivers by flood defences, and degraded by eutrophication for well over a century. The dynamic mosaic of temporary pools, side channels, and backwaters that once characterised large floodplains has been dramatically simplified, and with it the habitat template on which muddy-water specialists depend. Species such as the weatherfish and the European mud minnow, which rely on exactly these small, shallow, oxygen-fluctuating waters, have consequently declined across much of their range, making them priorities for national and international conservation lists.

Fish have always held a firm place in European culture and are closely linked to the human use of water bodies, from fisheries to folklore. The little-known inhabitants of wetlands reveal another side of this relationship: they demonstrate just how closely the conservation of individual species is tied to the protection of their habitats. Unlike mobile species that can shift between environments, wetland specialists succeed or fail with the wetlands themselves. Research on these fish therefore does more than fill taxonomic and ecological gaps; it can help raise public awareness of the importance of wetlands as a whole and lay the groundwork for more effective biodiversity conservation, framing habitat protection not as an abstract goal but as the concrete condition for the survival of identifiable, vulnerable species.

The newly published special issue offers a snapshot of current research on these specialised fish species and makes selected results of the Vienna conference available to the wider scientific community. For the editors and contributors, the hope is that the collection will serve as both a scientific resource and a call to action: a demonstration that Europe’s muddy waters, and the remarkable fish that inhabit them, deserve a permanent place on the conservation agenda rather than the margins of attention they have long occupied.

Subject of Research: Biology and conservation of threatened wetland fish species in Europe

Article Title: New special issue highlights threatened fish of European wetlands

Article References: New special issue highlights threatened fish of European wetlands. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: wetland fish, Nature Conservation, European mud minnow, weatherfish, crucian carp, floodplains, invasive species, biodiversity, habitat conservation, ecosystem indicators, Vienna conference, Pensoft

The team converted these compliance assumptions into “scenario-based” restoration targets. Rather than representing exact legal obligations or implementation plans, the method creates stylized targets that assume a fixed share of disturbed seminatural open wetlands is restored to reach Article 4 percentage goals. For each country and wetland type, restoration area was computed as the mandated proportion applied to the estimated disturbed wetland area.

Disturbed areas were assembled from country-level datasets, with uncertainty carried through the analysis. The study used Monte Carlo propagation (n = 5,000 draws) to produce confidence intervals, reflecting variability in the underlying wetland area estimates and in the disturbance-to-allocation procedure.

Across the EEA38 region, the results suggest that by 2030 about 2.66 million hectares of wetlands need restoration. On average, that translates to roughly 70,000 hectares per country, but several nations require far more. The United Kingdom tops the list with 403,700 ± 99,300 hectares, followed by Ireland (290,300 ± 73,600), Turkey (237,500 ± 100,400), and Romania (200,700 ± 68,400).

The pattern is not simply about land size. Germany, for example, would need 105,600 ± 52,200 hectares—less than the UK by nearly a factor of four—while France (173,900 ± 57,400), Denmark (144,400 ± 51,200), and Norway (141,700 ± 33,500) also exceed the regional mean.

In northern Europe, peatbogs strongly shape demand. Peatbog-specific restoration targets reach 234,000 ± 71,300 hectares in the UK and 256,900 ± 64,900 hectares in Ireland, with Sweden (91,600 ± 35,100) and Norway (38,000 ± 14,600) also showing substantial peatland components. Countries with limited peatbog extent—such as Turkey and Romania—show large overall targets driven instead by inland marsh systems.

Overall, the study links restoration “demand” to the spatial mix of seminatural wetland types and how frequently they are disturbed. It also highlights a policy challenge: without harmonized, spatially detailed wetland datasets, comparing restoration commitments across countries may be difficult to do robustly.

Subject of Research: EU wetland restoration targets under Habitats Directive Article 4, based on disturbed seminatural wetlands.

Article Title: Highly fragmented European wetlands with uneven restoration needs.

Article References: Kovács, G.M., Tong, X., Gominski, D. et al. Highly fragmented European wetlands with uneven restoration needs. Nature (2026). https://doi.org/10.1038/s41586-026-10760-9

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41586-026-10760-9

Keywords: wetlands, restoration targets, Habitats Directive, seminatural wetlands, peatbogs, disturbance, Europe, Monte Carlo uncertainty, biodiversity policy