We describe Bollmanella amorensis sp. nov. from Labor of Love Cave, White Pine County, Nevada, United States. From cave explorations in Great Basin National Park and Humboldt-Toiyabe National Forest in White Pine Co., Nevada, we provide new records of Idagona lehmanensis Shear, 2007, and Nevadesmus ophimontis Shear, 2009, and ecological notes on Labor of Love Cave, a list of species encountered, and remarks on the distinctiveness of caves in the Great Basin Desert.
A new troglomorphic species of the genus Otostigmus Porat, 1876 has been discovered in two hypogenic caves in Serra da Bodoquena National Park, a hotspot for Brazil’s subterranean fauna. This represents the second troglobitic Otostigmus species in the world. The newly described species, Otostigmus (Parotostigmus) troglobius sp. nov ., was based on molecular and morphological data. Although the specimens do not occur in the same cave, species delimitation analysis using a mitochondrial marker Cytochrome C Oxidase subunit I (COI) grouped the new species into a congruent MOTU. Morphologically, the new species closely resembles O. tidius Chamberlin, 1914 due to the median keels on the tergites and the short, incomplete sutures on the sternites. The new discovery underscores the importance of conserving the caves in Serra da Bodoquena.
The biodiversity of two caves in the Bavarian Alps, one at low altitude (Angerlloch) and the other at high altitude (Schrecksattel Ice Cave), was studied, with particular attention paid to the relative abundance of trogloxene, troglophile, and troglobitic species. Two excursions were organised for each cave to collect specimens and set pitfall traps for three months. A total of 32 species were identified in the Angerlloch and 16 in the Schrecksattel Ice Cave. Greater total biodiversity was observed in Angerlloch, but most of this fauna consisted of non-troglomorphic trogloxene species. In the Schrecksattel Ice Cave, only 16 species were found, but some of these were more highly adapted to life underground. Our results indicate that the low-altitude cave attracts a greater diversity of species with a low degree of cave adaptation, whereas the high-altitude cave harbours fewer species overall but has a more specialised troglobitic fauna. The results and species lists are presented herein. Furthermore, the occurrence of the springtail Protaphorura septempapillata (Palissa, 1986) was documented for the first time in the Schrecksattel Ice Cave, representing the second cave record for this species beyond its type locality.
Karst groundwater ecosystems can rely on organic matter (OM) sourced from the surface, but dependance on this can be unreliable depending on how surface water recharges the subsurface. Instead, autochthonous, chemolithoautotrophically-produced OM can also support karst ecosystems. The reduced compounds fueling chemolithoautotrophy can be derived from both OM decomposition and mineral dissolution. The relative contributions of allochthonous versus autochthonous OM to stygofaunal food webs remain unassessed in most settings. Here, we examined OM contributions to metazoan communities in the Barton Springs segment of the Edwards Aquifer (Texas, USA). Geochemical gradients corresponded to variations in microbial community compositions, and biomass-weighted metabolic profiling provided evidence for chemolithoautotrophic OM production, particularly in sulfidic wells where heterotrophic contributions to fine particulate OM (FPOM) were the lowest. Chemolithoautotrophic contributions to OM were calculated using Bayesian isotope mixing models of bulk stable carbon and nitrogen isotope ratios of FPOM, with chemolithoautotrophic contributions as high as 44.8% in one groundwater well. However, bulk δ¹³C of metazoan assemblages were not strongly depleted (< -35‰), and Bayesian isotope mixing models indicated diets primarily supported by allochthonous OM instead of chemolithoautotrophic OM. The dampened isotopic evidence for chemolithoautotrophy may be due to the hydrologic dynamics of the Barton Springs segment, where rapid recharge and relatively short groundwater residence times likely promote allochthonous OM use by stygofauna. These findings highlight the importance of hydrologic context in determining energy pathways in subterranean food webs and have implications for understanding the vulnerability of stygobiontic communities to changes in land use, including urban development.
Two new taxa of the earthworm genus Amynthas Kinberg, 1867 are described from northwestern China: Amynthas longnanensis sp. nov . from Longnan, Gansu Province, and Amynthas pectiniferus guanzhongensis ssp. nov . from Weinan, Shaanxi Province. Both belong to the A. sieboldi group, characterized by three pairs of spermathecal pores in 6/7–8/9. Species delimitation based on COI barcoding (ASAP and GMYC) and phylogenetic analysis using mitogenomic protein-coding genes (PCGs) support their recognition as distinct lineages. The mitogenomic phylogeny reveals that the A. sieboldi group as currently defined is not monophyletic. The new findings fill a distributional gap of Amynthas in northwestern China and provide new morphological and molecular data for understanding earthworm diversity.
The arachnid order Palpigradi remains poorly studied, particularly with respect to patterns of morphological adaptation to subterranean environments. Subterranean adaptation in palpigrades and comparison with endogean species has been documented scarcely. In this study, Eukoenenia serrana sp. nov. is described as a new species in the E. mirabilis-berlesei group from the cave Sima del Pla de Llomes in eastern Spain. The new species exhibits pronounced troglomorphic features, including large body size and strong elongation of appendicular elements, particularly leg I, while retaining diagnostic characters of the group like the single lateral prosomal organ. We explored the morphological differentiation between endogean and hypogean species in the E. mirabilis-berlesei group, a lineage traditionally regarded as endogean and only marginally associated with caves. An analysis of elongation patterns, with an emphasis on the palp and legs, showed clear differences between species from different habitats using a set of linear measurements and derived ratios related to body and their appendages size. Hypogean species consistently show marked elongation of tibia I, basitarsus IV, and combined tarsus–tibia lengths, whereas changes in overall body characters are more moderate. In contrast, the basitarsus IV/tibia IV ratio remains largely unchanged, indicating proportional elongation of these segments. Highly cave-adapted species in this group retained a single blade in the lateral organ, suggesting that sensory and appendicular traits may evolve independently. The results reveal a mosaic pattern of subterranean adaptation within the E. mirabilis-berlesei group and by extension in palpigrades.
Shallow groundwater habitats, including hypotelminorheic seeps, support highly specialized and often narrowly endemic fauna, yet biodiversity in these systems remains poorly documented, particularly in urban landscapes. Here, we describe two new stygobiotic amphipod species, Stygobromus scottsruni sp. nov. and Stygobromus paveki sp. nov., from hypotelminorheic habitats in the Washington, D.C. metropolitan region, and report new locality records for S. anacostensis . Morphological and molecular analyses place both new species within the Stygobromus tenuis species group. Phylogenetic analyses based on mitochondrial (co1+16S) and nuclear (28S) loci, together with multiple species delimitation approaches, consistently support the recognition of both taxa as distinct evolutionary lineages. Despite occurring in close geographic proximity to other congeners, both species exhibit strong genetic differentiation and extremely restricted distributions, consistent with fine-scale isolation among shallow groundwater systems. With the addition of these taxa, described stygobiotic amphipod species richness from the Piedmont and Atlantic Coastal Plain of Maryland, Virginia, and the District of Columbia now totals 16 species, 10 of which are known from in and around the Washington, D.C. metropolitan area, based on currently described taxa. These results highlight hypotelminorheic habitats as important centers of micro-endemism and demonstrate that urban groundwater systems can harbor unexpectedly high levels of cryptic subterranean biodiversity, underscoring the need for targeted surveys and conservation attention to shallow subterranean ecosystems.
Two new species of Galloisiana Caudell, 1924, G. harimensis sp. nov . and G. kawamurai sp. nov ., are described. In general appearance, both new species resemble G. nipponensis (Caudell & King, 1924), the type species of the genus. Molecular phylogeny reconstructed in the present study shows that the new species belong to clades different from that of G. nipponensis . Morphologically, the three species can be distinguished based on the male genitalia, although the females resemble each other.
A new stygobiont hydrobiid genus and species is described from the Stymphalia karst basin (Peloponnese, Greece). Cyllena hermes gen. et sp. nov. is distinguished from other valvatiform or valvatiform-planorboid stygobiont hydrobiids by a unique combination of shell and anatomical characters, supporting the establishment of a new monotypic genus. It is currently known from a single karstic spring connected to the subterranean hydrological network of the Stymphalia polje, indicating a highly localized distribution. Following a precautionary approach, and in accordance with IUCN criteria, the species is here considered to qualify as Vulnerable (VU D2). The discovery of the new genus contributes to the documentation of subterranean aquatic gastropod diversity in Greece and emphasizes the need for further targeted exploration of karst ecosystems in the region.
More than 26,000 caves occur in the extensive Brazilian territory, distributed across the country’s five geopolitical regions. Some of these caves have been studied for the biodiversity they harbor; however, many groups of organisms are neglected, as is the case with myxomycetes. Herein we present the second record of myxomycetes in Brazilian caves, based on specimens sampled in a cave in the Central-West region, in the state of Goiás. Leaf litter and decaying wood fragments from the photic, penumbra, and aphotic zones were incubated in humid chambers and monitored for 90 days. Of the 22 humid chambers prepared, 45% were positive. Three species were identified: Arcyria cinerea (Arcyriaceae), Cribraria elegans (Cribrariaceae), and Perichaena depressa (Trichiaceae), in addition to one unidentified specimen. This study, the first conducted in Cerrado caves, expands the known occurrence of myxomycetes in Brazilian subterranean environments, reporting Cribrariaceae and P. depressa for the first time in caves and A. cinerea for the first time in a Brazilian Cerrado cave.
Groundwater-obligate taxa (stygobionts) exhibit variable degrees of habitat specialization, ranging from those restricted to single micro-habitats to generalists occurring in a broad range of habitat types. The karstic Edwards Aquifer is the most biodiverse and well-studied groundwater habitat in the continental United States, but some Edwards Aquifer-associated species also occupy the hyporheic zone of rivers downstream from karst. The goals of this research were to 1) assess the potential of the off-karst hyporheic zone as habitat for ‘karst’ species and 2) to determine how stygobiont richness, diversity, and abundance related to distance from karst in the hyporheic zone of a spring-dominated river system. We enumerated stygobionts and quantified environmental characteristics for 55 samples from 11 sites in the San Marcos River between 3 and 140 river kilometers downstream from the rivers’ spring source. Linear mixed effects models and variance partitioning were used to investigate relationships between stygobiont assemblage metrics and environmental parameters (distance from karst, temperature, dissolved oxygen, and hydraulic conductivity). Stygobiont richness and diversity were significantly affected by distance from karst. Stygobiont richness and abundance were significantly affected by hydraulic conductivity. In richness and diversity models, predictive power was low, and additional environmental variables were significant in all models. This study demonstrates that stygobiont communities in the hyporheic zone can be structured by both local environmental conditions, via habitat filtering, and to a lesser extent, by spatial effects (i.e., proximity to source populations in adjacent aquifers). Furthermore, habitat specificity is poorly characterized for stygobiont taxa, inhibiting effective conservation planning and implementation.
The Cytochrome-b sequences of 41 Myotis capaccinii samples from eight localities in Türkiye were analyzed phylogenetically, taking into account European, Tunisian, and Iranian samples. Nine haplotypes were identified, including previous sequences from Türkiye, and three of these haplotypes were recorded for the first time from two Mediterranean locations. The genetic distance between the Turkish and European samples was 3.0%, ranging from 0.10% to 0.76% among the six Turkish population groups examined. Haplotype diversity (Hd) and nucleotide diversity (Pi) for the Turkish samples were 0.786 and 0.005, respectively, which were quite similar to those for the European samples. In the Bayesian Inference tree, the Bulgarian and Turkish samples were placed in a different clade from other European samples. In the constructed Median-joining network, although common haplotypes were found among the Tunisian, European, Turkish, and Iranian subpopulations, the haplotype differentiation in the Bulgarian and Turkish samples was evident. Accordingly, in previous studies, the European subpopulation was included in the nominal subspecies, while the Bulgarian and Turkish specimens were considered M. capaccinii bureschi. The low genetic diversity among subpopulations is thought to be related to the species’ dispersal ability, with European specimens dispersing into southeastern Mediterranean refugia during the Last Glacial Maximum, exchanging genes with Thracian and Anatolian specimens. Furthermore, the level of genetic diversity within the Bulgarian and Turkish specimens within the same haplogroup provides evidence that no other subpopulation within Türkiye has differentiated at the subspecies level.
To elucidate the species composition and genetic diversity patterns of earthworms in urban green spaces in Northeast China, this study systematically investigated 42 urban parks across the region. Based on mitochondrial cytochrome c oxidase subunit I (COI) gene sequences, the genetic diversity, population structure, and phylogeographic patterns of the dominant species were analyzed. A total of 604 earthworm individuals were collected and identified, belonging to 12 species from seven genera and three families. Genetic analysis of the dominant species revealed that Drawida ghilarovi sensu lato Gates, 1969 exhibited the highest genetic diversity, with its haplotypes forming six independent clades in the phylogenetic tree. The haplotype network displayed a typical reticulate structure with no shared haplotypes, indicating significant population differentiation in this species. Drawida japonica sensu lato (Michaelsen, 1892) showed high haplotype diversity and nucleotide diversity, with a star-like radiation pattern in the haplotype network, suggesting that the population may have undergone a recent rapid expansion event. In contrast, Aporrectodea caliginosa (Eisen, 1874) and Metaphire tschiliensis (Michaelsen, 1928) exhibited relatively low genetic diversity; however, multiple shared haplotypes across geographically distinct populations were detected, which may reflect historical gene flow or shared ancestral origins. This study provides the first comprehensive elucidation of the species composition and genetic diversity patterns of earthworms in urban parks in Northeast China, offering an important foundation for understanding the biogeographic evolution of earthworm communities in urban green spaces in this region.
Subterranean ecosystems host highly specialized and often endemic crustacean faunas, yet ostracods inhabiting chemically extreme sulfidic caves remain poorly documented. In this study, a new stygobiont species of the genus Pseudocandona is described from a sulfidic cave in Albania using an integrative taxonomic approach combining detailed morphological analyses and molecular data. Subterranean ostracods exhibit a suite of morphological, physiological, and life-history adaptations to the energetic constraints of groundwater habitats, and species thriving in sulfidic systems additionally tolerate high concentrations of hydrogen sulfide and hypoxia. The new species, Pseudocandona sulphurella sp. nov., belongs to the rostrata group, a clade otherwise dominated by surface-water taxa and with only one previously known stygobiont representative. Its valves and soft parts are frequently covered by sulfur-oxidizing bacterial epibionts, a feature shared with other crustaceans from sulfidic environments and potentially indicative of mutualistic interactions. Phylogenetic analyses based on COI and 28S sequences place the new species within a moderately supported clade of Western Palearctic Pseudocandona, while also highlighting the likely polyphyly of the genus. The discovery of P. sulphurella sp. nov. represents the first record of a stygobiont ostracod in Albania and expands current knowledge of biodiversity in chemoautotrophic subterranean ecosystems. This finding underscores the evolutionary significance of sulfidic caves as natural laboratories for studying adaptation, speciation, and the ecological dynamics of groundwater crustaceans.
This article describes a new species of cavesnail, Erhaia dijiang Y.-M. He, H.-Q. Xiang, Y.-F. Zhou & H. Zheng, sp. nov ., collected from a cave in Hongta District, Yuxi City, Yunnan Province, China. This species is a member of the family Erhaiidae, characterized by the absence of eyes. It represents the highest-altitude distribution among known cave-dwelling Erhaiidae species, and is the first freshwater cavesnail discovered in China.
We provide redescriptions of two subterranean species of the genus Oncopodura inhabiting caves of the Balkan Peninsula, namely O. cavernarum Stach, 1934 and O. jugoslavica Absolon & Kseneman, 1932, partly based on specimens from type localities. Oncopodura cavernarum differs from other species of the genus by a combination of the following characters: single lobe in PAO, unguis elongated, ungual basal lamella shorter than or equal to half the length of the unguis, mucro with 4 teeth and 2 basal scales, and pattern of hooks on dens: 1 dorsointernal hook on basal part, and 1 dorsoexternal and 1 dorsointernal hook on distal part. Oncopodura jugoslavica can be distinguished from other congeners by PAO with 4 equally short lobes, unguis elongated, ungual basal lamella longer than half the length of the unguis, mucro with 4 teeth and 2 basal scales, and pattern of hooks on dens: basal part with 1 dorsointernal hook, and distal part with 1 dorsoexternal and 2 dorsointernal hooks. In both species, the modification of the foot complex shows a moderate level of troglomorphy. Regarding the geographical distribution, these two Dinaric Oncopodura species occur in allopatry: O. cavernarum has north-western and central merodinaric distribution range, while O. jugoslavica is characterized by a south-eastern merodinaric distribution. For both redescribed species, tables with diagnostic characters of morphologically similar congeners are provided.
We report the first troglobitic members of the scorpion family Bothriuridae from Australia, discovered in the Pilbara region of Western Australia, and provide a brief review of Australian troglofaunal scorpions. Scorpions are rare in subterranean ecosystems, with only 28 species recorded globally. Two described and two undescribed subterranean scorpion species were previously known from Australia. The Pilbara specimen documented herein exhibit pronounced troglomorphic traits, including complete loss of ocelli and pigmentation and weakened/diminished appendages, consistent with obligate subterranean adaptation. Morphological and phylogenetic analyses place the specimen within Bothriuridae. Photographs, collection details, and molecular data are provided. Together with a previously collected undescribed bothriurid from the Pilbara, this discovery represents the first documented troglobitic Bothriuridae globally. Formal taxonomic treatment will follow in a subsequent dedicated study.
Subterranean ecosystems harbor a high diversity of narrow-range endemics, yet they remain largely invisible in conservation planning, representing a major bias that may trigger irreversible biodiversity loss under rapid climate change. This study applied an Ensemble of Small Models (ESMs) framework, coupled with a target-group background strategy, to assess the climate vulnerability and protection status of Zopherobatrus Yin & Li, 2015 (Coleoptera: Staphylinidae: Pselaphinae), an extremely rare troglobitic rove beetle genus endemic to the karst landscapes of southwest China. Habitat suitability was projected under current conditions and across the 2050s and 2070s (SSP1-2.6 and SSP5-8.5). Under current conditions, highly suitable habitat is strictly confined to specific karst terrains; future projections reveal that the retained habitat ratio declines to only 24.0-48.2%, while the conventional net area change metric (-36.4% to-63.1%) masks functional habitat loss because climatically "gained" areas remain ecologically inaccessible to this dispersal-limited group, and the projected range centroid shifts northwestward by up to 141 km. A systematic gap analysis, cross-referenced with national and provincial nature reserves, showed that only 2.6% of current suitable habitat is formally protected, all known localities fall entirely outside reserves, and 95.9% of identified climate refugia lack any legal protection. These findings quantified a "double jeopardy" for subterranean biodiversity: simultaneous habitat erosion driven by climate change combined with a near-total absence of formal protection. The establishment of targeted micro-reserves centered on climate refugia, the formal inclusion of Zopherobatrus in national protection lists, and the integration of subterranean fauna into regional conservation frameworks are recommended.
The Dinarides of Bosnia and Herzegovina are exceptionally rich in surface and subterranean geomorphological and hydrological karst features which make them an ideal setting for ecological studies of microorganisms. This work presents the results of a seven-year study of testate amoebae, polyphyletic eukaryotic microorganisms, across various karst habitats. The main objectives were to collect data on testate amoebae biodiversity and to deepen our understanding of the transformation of their assemblages across surface and subterranean habitats. More than 50 taxa of testate amoebae were identified, including the notable finding of Psammonobiotus dinarica – a species originally described from caves – in a pristine surface karst river. A Jaccard resemblance-based cluster analysis of overall testate amoebae biodiversity revealed a clear separation of lake assemblages from river, spring, soil and cave assemblages. These results were confirmed by site-based cluster analysis and NMDS ordination, which showed strong separation (SIMPROF test) of lake, soil and cave assemblages, but also distinct assemblages of hydrologically interconnected karst features (sinking river Šuica → sinkhole cave Ponor Kovači → the resurgence Vrilo Spring). This study confirms a high similarity between river, spring, cave, and soil assemblages but reveals a previously unknown distinction of lake assemblages. It also showed that spring assemblages have higher similarity to river assemblages than to those in caves, implying a possible impact of primary production due to diffuse light in springs during summer droughts. This study emphasizes the need for further research of microbial assemblages in relation to environmental factors in order to support science-based protection of both surface and subterranean karst ecosystems.
