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Hipposideros spp. are insectivorous bats and karst cave dwellers. This study aimed to study the roosting ecology, reproduction, and population fluctuations of three species H. diadema, H. larvatus, and H. ater in Gunung Sewu Karst region, Indonesia. Age and reproductive status of individuals were identified and analyzed using a combination of forearm length (FA) and body mass grades (W). Multiple regression analysis was used to determine the correlation between population size, rainfall and population structure based on FA, reproductive status, and W. Crude birth rate (CBR) and general fertility rate (GFR) were used to determine the population’s birth rate and female fertility. The results showed that the population of the three Hipposideros species were quite stable over the year with a peak in January which classified them as monoestrous, with mating, pregnancy, and lactation occurring once a year with no delay between mating and pregnancy. Pregnancy lasted 8–12 weeks and lactation 4–5 weeks. The population structure of the three species tended to be stable over the year. The CBR and GFR values can be used for rapid assessment guidelines in an area. [ABSTRACT FROM AUTHOR]

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The Dinaric Karst is a global hotspot for subterranean diversity, with two distinct peaks of species richness in the northwest and southeast, and an area of a lower species richness in the central part. In this article, we present a species list and describe the ecological conditions of the Lukina jama–Trojama cave system, located in the central part of the Dinaric Karst. This cave system is the deepest and one of the most logistically challenging cave systems sampled so far in the Dinaric Karst. Repeated sampling resulted in a list of 45 species, including 25 troglobionts, 3 troglophiles, 16 stygobionts, and 1 stygophile. Most of the recorded species are endemic to the Velebit Mountain, while three species are endemic to the Lukina jama–Trojama cave system. Within the system, species richness peaks in the deepest third of the cave, most likely reflecting the harsh ecological conditions in the upper parts, including ice, cold winds, and occasional waterfalls. Milder and more stable deeper parts of the cave contain a rich subterranean species community, part of which is associated with two very distinct aquatic habitats, the cave hygropetric and the phreatic zone. The newly recognized hotspot of subterranean biodiversity in the central Dinaric Karst, which has emerged between the two known centers of biodiversity, further highlights the species richness in large cave systems, but also challenges the diversity patterns in the Dinaric Karst overall.

Specialized subterranean species are iconic examples of convergent evolution driven by environmental constraints, representing an ideal model system for eco-evolutionary studies. However, scientific research on the behavioural adaptations of subterranean organisms has lagged and is biased mostly towards a few model species. Through a systematic literature review, we aimed to assess quantitatively whether a congruent evolution of behavioural traits among subterranean species exists. We considered four types of behaviours (exploratory, feeding, social and anti-predator) and tested predictions about their occurrence among species with different degrees of adaptation to subterranean environments. We argue that these behaviours constitute the earliest adaptations to three main ecological factors characterizing subterranean habitats, namely the constant darkness, the limited food resources and the reduced predator pressure. Darkness selects for individuals that rely on non-visual cues to explore their surroundings, track food resources and locate potential sexual partners. The reduced availability of food promotes high foraging plasticity and deters species from adopting aggressive behaviours towards conspecifics. The reduced predator pressure allows species to abandon specific anti-predator behaviours and permits safer execution of their biological activities. Our analyses show that these four behaviours are likely to represent the result of an early convergent adaptation to the subterranean realm. [ABSTRACT FROM AUTHOR]

An extraordinary longevity has been observed in some cave species, and this raised the hypothesis that a longer lifespan may be considered one of the characteristic traits of these animals. However, only a few cave species have been studied thus far, and a firm conclusion remains to be drawn. Here we review the available knowledge on the longevity of subterranean species, point out the limitations of previous studies, and provide suggestions for future studies to answer important questions regarding the longevity in cave animals, its adaptive value and the related promoting factors. We also argue that studying the longevity in cave animals will contribute to the field of aging, especially to understanding the evolution of this phenomenon.

Abstract: Supercooling points (SCPs), lower lethal temperatures (LLTs), and the effect of short-term exposures (1min) to low temperatures were examined in the adults of two stenothermal leptodirin species, Neobathyscia mancinii and Neobathyscia pasai (Coleoptera, Cholevidae). Specimens were collected from two caves in the Venetian Prealps (NE-Italy). Inter-species comparison highlighted lower values of SCP in N. mancinii (−7.1±0.9°C) than in N. pasai (−6.4±0.3°C), with no significant intersexual differences in both species. N. pasai (LLT50±SE=−16.96±2.30°C; LLT100=−25.41°C) tolerated short exposures to subzero temperatures better than N. mancinii (LLT50±SE=−4.89±1.08°C; LLT100=−11.72°C). According to the mortality and cumulative proportion of individual freezing curves (CPIF), SCPs and LLT100, N. pasai may be defined as “strongly freeze tolerant”, N. mancinii as “moderately freezing tolerant”. Overall, these results may justify the different in-cave habitat selection showed by the two species (N. pasai was abundant close to the entrance where the temperature is variable whereas N. mancinii was confined to the internal part of the cave where the temperature is constant throughout the year), and suggest hypotheses on the effects of such habitat selection on freeze tolerance strategy adopted. Finally, they give new insights into possible responses to climate changes in cave dwelling species. [ABSTRACT FROM AUTHOR]

Although there are no published studies and limited data documenting damage by rodents in Hawaiian caves, our incidental observations during more than 40 years of surveying caves indicate that introduced rodents, especially the roof rat, Rattus rattus, pose significant threats to vulnerable cave resources. Caves, with their nearly constant and predictable physical environment often house important natural and cultural features including biological, paleontological, geological, climatic, mineralogical, cultural, and archaeological resources. All four invasive rodents in Hawai‘i commonly nest in cave entrances and rock shelters, but only the roof rat (Rattus rattus) habitually enters caves and utilizes areas in total darkness. Skeletons and feces have been found in the deepest passages, sometimes over a kilometer from the nearest known entrance although the animals may have used nearby small, inconspicuous entrances. Their impacts include damage to rare native plants in cave entrances; predation on vulnerable cave-inhabiting species, such as Thaumatogryllus tree crickets, and native moths roosting in caves; destruction of the irreplaceable remains of the extinct terrestrial fauna; damage to organic material associated with cultural and archaeological resources, thereby obscuring the historical record of humans in the islands; introduction of unnatural nutrients into subterranean ecosystems via their bodies and feces allowing the colonization of caves by other harmful alien species; and disturbance of research sites. Furthermore, the extirpation of colonies of cave-roosting moths has impacted native birds nesting in the entrance and twilight zones.

Bats (Chiroptera) are divided into two suborders (Yinpterochiroptera and Yangochiroptera). More than 50% of species of bats use caves as their roosting sites. Thus, they play a crucial role in the cave ecosystem. For that reason, they also exist as keystone species in the karst area. Gunung Sewu is one of the karst areas in Indonesia that best exemplifies tropical karst. Furthermore, Gunung Sewu is still at risk of habitat loss despite being designated as a Geopark. This study aimed to understand the diversity of bats that live in caves in the karst region of Gunung Sewu, specifically in four caves near Ngobaran Beach between April and June 2020. A harp net and misnet placed at the cave’s entrance were used to capture bats for data collection. After they were captured, the bats were identified using Morphometry and the Shannon-Wiener index. Through another index, Margalef index, the bat diversity in the four cave habitats was expressed, with a discovery that there are many different species. Based on the Jaccard similarity index, bats were categorized again using cluster analysis and the unweighted pair-group method using arithmetic averages (UPGMA). A total of nine species across five families were identified. The diversity of existing species variety was also recognized by analyzing the composition of the four cavern inhabitants. The four cave ecosystems’ bat diversity was divided into three categories: moderate variety, low similarity, and high species diversity. Except for Cekelan 1 Cave and Gebyog Cave (P=0.015), other variations did not demonstrate a meaningful difference (P0.05). This demonstrates how different each ecosystem is. Therefore, they could be classified as potentially spoiled habitats, demanding additional conservation efforts.

Abstract Background The underlying mechanisms and processes that prompt the colonisation of extreme environments, such as caves, constitute major research themes of evolutionary biology and biospeleology. The special adaptations required to survive in subterranean environments (low food availability, hypoxic waters, permanent darkness), and the geographical isolation of caves, nominate cave biodiversity as ideal subjects to answer long-standing questions concerning the interplay amongst adaptation, biogeography, and evolution. The present project aims to examine the phylogeographic patterns exhibited by two sympatric species of surface and cave-dwelling peracarid crustaceans (Asellus aquaticus and Niphargus hrabei), and in doing so elucidate the possible roles of isolation and exaptation in the colonisation and successful adaptation to the cave environment. Results Specimens of both species were sampled from freshwater hypogean (cave) and epigean (surface) habitats in Hungary, and additional data from neighbouring countries were sourced from Genbank. Sequencing of mitochondrial and nuclear loci revealed, through haplotype network reconstruction (TCS) and phylogenetic inference, the genetic structure, phylogeographic patterns, and divergence-time estimates of A. aquaticus and N. hrabei surface and cave populations. Contrasting phylogeographic patterns were found between species, with A. aquaticus showing strong genetic differentiation between cave and surface populations and N. hrabei lacking any evidence of genetic structure mediated by the cave environment. Furthermore, N. hrabei populations show very low levels of genetic differentiation throughout their range, which suggests the possibility of recent expansion events over the last few thousand years. Conclusions Isolation by cave environment, rather than distance, is likely to drive the genetic structuring observed between immediately adjacent cave and surface populations of A. aquaticus, a predominantly surface species with only moderate exaptations to subterranean life. For N. hrabei, in which populations exhibit a fully ‘cave-adapted’ (troglomorphic) phenotype, the lack of genetic structure suggests that subterranean environments do not pose a dispersal barrier for this surface-cave species.

The Snezhnaya (=Snow) Cave System (depth −1760 m; total length 40.8 km), located in the West Caucasus, is inhabited by distinctly troglomorphic collembolan species from several families. Two new species of the family Arrhopalitidae occur in the deep parts of the system. Both are highly morphologically specialized; however, they evolved into different troglobiont life forms. Arrhopalites profundus sp. nov. with extremely long claws, lamellate mucro, and an enlarged sensory organ of third antennal segment lives exclusively in hygropetric and epineustonic habitats, whereas Pygmarrhopalites rystsovi sp. nov., with greatly elongated and multi-subsegmentated antennae and long legs, prefers open terrestrial spaces. The troglomorphy, as well as ecological life forms of the obligate cave-dwelling Arrhopalitidae, in general, are discussed and classified as neustonic-hygropetric, atmobiont, intrasubstrate, and intermediate troglomorphs.

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Animals that inhabit subterranean environments often undergo various distinct phenotypic modifications (referred to as "troglomorphy") as they transition to life in perpetual darkness. However, the molecular basis behind troglomorphy remains poorly understood, particularly in regards to the mechanisms involved in the reduction and/or loss of traits at the transcriptomic level. In this study, we investigate the transcriptional basis behind vision loss in populations of cave-dwelling crustaceans. We employ phylogenetic and transcriptomic methods on surface and cave-adapted populations of an emerging model species for biospeleology, the isopod Asellus aquaticus (Linnaeus, 1758), and the amphipod Niphargus hrabei S. Karaman, 1932. These two species show contrasting directionality in the surface-cave transition, which positions them as ideal study subjects. Asellus aquaticus is common in surface waters and is only occasionally found in caves, where its populations present different degrees of eye reduction and pigmentation. On the other hand, the eyeless N. hrabei has successfully colonized surface environments despite belonging to an almost exclusively cave-dwelling genus. By sequencing and assembling robust de novo transcriptomes we characterized differences in visual genes and pathways among surface and cave populations of the aforementioned species. Our results indicate that despite having reduced eyes, recent cave colonizer A. aquaticus is still capable of expressing functional visual opsins and major components of the phototransduction pathway within the cave. Niphargus hrabei, a species with an ancient cave origin, shows no clear indication of being capable of sight. However, the expression of putative functional visual opsins and other phototransduction genes was maintained, which suggests that this eyeless species might be capable of extraocular photoreception. With the present study, we aim to bring forth the Molnár János Cave system as a promising research avenue to improve our understanding of patterns of reduction and loss of vision in caves and other aphotic environments. [ABSTRACT FROM AUTHOR]

Our understanding of the evolutionary history and ecology of cave-associated species has been driven historically by studies of morphologically adapted cave-restricted species. Our understanding of the evolutionary history and ecology of nonrestricted cave species, troglophiles, is limited to a few studies, which present differing accounts of troglophiles' relationship with the cave habitat, and its impact on population dynamics. Here, we used phylogenetics, demographic statistics, and population genetic methods to study lineage divergence, dates of divergence, and population structure in the Cave Salamander, Eurycea lucifuga, across its range. In order to perform these analyses, we sampled 233 individuals from 49 populations, using sequence data from three gene loci as well as genotyping data from 19 newly designed microsatellite markers. We find, as in many other species studied in a phylogeographic context, discordance between patterns inferred from mitochondrial relationships and those inferred by nuclear markers indicating a complicated evolutionary history in this species. Our results suggest Pleistocene-based divergence among three main lineages within E. lucifuga corresponding to the western, central, and eastern regions of the range, similar to patterns seen in species separated in multiple refugia during climatic shifts. The conflict between mitochondrial and nuclear patterns is consistent with what we would expect from secondary contact between regional populations following expansion from multiple refugia. [ABSTRACT FROM AUTHOR]

Ashley, D.C. Department of Biology, Missouri Western State College. A DESCRIPTION OF TWO BIOSPELEOLOGY COURSES AVAILABLE TO MISSOURI STUDENTS. B10355 (Cave Ecology) is a three credit course available to students [...]

Abstract Background Bacteria present in cave often survive by modifying their metabolic pathway or other mechanism. Understanding these adopted bacteria and their survival strategy inside the cave is an important aspect of microbial ecology. Present study focuses on the bacterial community and geochemistry in five caves of Mizoram, Northeast India. The objective of this study was to explore the taxonomic composition and presumed functional diversity of cave sediment metagenomes using paired end Illumina sequencing using V3 region of 16S rRNA gene and bioinformatics pipeline. Results Actinobacteria, Proteobacteria, Verrucomicrobia and Acidobacteria were the major phyla in all the five cave sediment samples. Among the five caves the highest diversity is found in Lamsialpuk with a Shannon index 12.5 and the lowest in Bukpuk (Shannon index 8.22). In addition, imputed metagenomic approach was used to predict the functional role of microbial community in biogeochemical cycling in the cave environments. Functional module showed high representation of genes involved in Amino Acid Metabolism in (20.9%) and Carbohydrate Metabolism (20.4%) in the KEGG pathways. Genes responsible for carbon degradation, carbon fixation, methane metabolism, nitrification, nitrate reduction and ammonia assimilation were also predicted in the present study. Conclusion The cave sediments of the biodiversity hotspot region possessing a oligotrophic environment harbours high phylogenetic diversity dominated by Actinobacteria and Proteobacteria. Among the geochemical factors, ferric oxide was correlated with increased microbial diversity. In-silico analysis detected genes involved in carbon, nitrogen, methane metabolism and complex metabolic pathways responsible for the survival of the bacterial community in nutrient limited cave environments. Present study with Paired end Illumina sequencing along with bioinformatics analysis revealed the essential ecological role of the cave bacterial communities. These results will be useful in documenting the biospeleology of this region and systematic understanding of bacterial communities in natural sediment environments as well.

The unique morphology of cave animals has interested biologists at least since the time of Lamarck. After a number of nonadaptive explanations for the morphology of cave animals, especially with respect to eye and pigment loss, a neo-Darwinian explanation, emphasizing constructive morphological changes rather than losses, was put forward by Barr, Christiansen, and Poulson in the 1960's. Emphasizing convergent evolution (troglomorphy), this paradigm has recently been challenged, with evidence of divergent selection and the widespread occurrence of morphologically similar species in other subterranean habitats, including ones with abundant food and relatively strong environmental fluctuations. An emerging paradigm emphasizes the central role of darkness in convergent evolution, and the role of habitat size and interspecific competition in divergent evolution of subterranean species. [ABSTRACT FROM AUTHOR]

Subterranean habitats house a wide range of species which show a number of adaptations to prevailing ecological conditions. Spiders are among the most abundant predators in caves; however, most studies on cave spiders focus on species adapted to these habitats. This is the first study related to the occurrence of the Black lace-weaver spider, Amaurobius ferox, in caves. The species lacks adaptations to the subterranean habitats and has been observed within meters from the cave entrance all year round, except in late winter until early spring. Furthermore, its occupancy is positively related to the presence of other three cave-dwelling spiders: Metellina merianae, Meta menardi and Tegenaria sp.

Background: Karst caves are considered as extreme environments with nutrition deficiency, darkness, and oxygen deprivation, and they are also the sources of biodiversity and metabolic pathways. Microorganisms are usually involved in the formation and maintenance of the cave system through various metabolic activities, and are indicators of changes environment influenced by human. Zhijin cave is a typical Karst cave and attracts tourists in China. However, the bacterial diversity and composition of the Karst cave are still unclear. The present study aims to reveal the bacterial diversity and composition in the cave and the potential impact of tourism activities, and better understand the roles and co-occurrence pattern of the bacterial community in the extreme cave habitats. Results: The bacterial community consisted of the major Proteobacteria, Actinobacteria, and Firmicutes, with Proteobacteria being the predominant phylum in the rock, soil, and stalactite samples. Compositions and specialized bacterial phyla of the bacterial communities were different among different sample types. The highest diversity index was found in the rock samples with a Shannon index of 4.71. Overall, Zhijin cave has relatively lower diversity than that in natural caves. The prediction of function showed that various enzymes, including ribulose-bisphosphate carboxylase, 4-hydroxybutyryl-CoA dehydratase, nitrogenase NifH, and Nitrite reductase, involved in carbon and nitrogen cycles were detected in Zhijin cave. Additionally, the modularity indices of all co-occurrence network were greater than 0.40 and the species interactions were complex across different sample types. Co-occurring positive interactions in the bacteria groups in different phyla were also observed. Conclusion: These results uncovered that the oligotrophic Zhijin cave maintains the bacterial communities with the diverse metabolic pathways, interdependent and cooperative co-existence patterns. Moreover, as a hotspot for tourism, the composition and diversity of bacterial community are influenced by tourism activities. These afford new insights for further exploring the adaptation of bacteria to extreme environments and the conservation of cave ecosystem. [ABSTRACT FROM AUTHOR]

Cave adaptation has evolved repeatedly across the Tree of Life, famously leading to pigmentation and eye degeneration and loss, yet its macroevolutionary implications remain poorly understood. We use the North American amblyopsid fishes, a family spanning a wide degree of cave adaptation, to examine the impact of cave specialization on the modes and tempo of evolution. We reconstruct evolutionary relationships using ultraconserved element loci, estimate the ancestral histories of eye‐state, and examine the impact of cave adaptation on body shape evolution. Our phylogenomic analyses provide a well‐supported hypothesis for amblyopsid evolutionary relationships. The obligate blind cavefishes form a clade and the cave‐facultative eyed spring cavefishes are nested within the obligate cavefishes. Using ancestral state reconstruction, we find support for at least two independent subterranean colonization events within the Amblyopsidae. Eyed and blind fishes have different body shapes, but not different rates of body shape evolution. North American amblyopsids highlight the complex nature of cave‐adaptive evolution and the necessity to include multiple lines of evidence to uncover the underlying processes involved in the loss of complex traits. [ABSTRACT FROM AUTHOR]

The genus Troglophilus Krauss includes species with a rather limited dispersal ability and a wide distribution range, making it a good model for biogeographic, phylogeographic and phylogenetic investigations, with growing interest in recent years. However, a crucial prerequisite for addressing biogeographic issues is the knowledge about species complete distribution range. In particular, Troglophilus cavicola (Kollar) and Troglophilus neglectus Krauss are the species of the genus Troglophilus with the widest distribution in Europe, where their main areal extends westward to Northern Italy, but their precise distribution and range limits are still uncertain. In this study, the presence of these two species, which overwinter in hypogean habitats, was investigated in caves of the westernmost area of Northern Italy (Lombardy, Provinces of Lecco and Como) where populations belonging to the genus Troglophilus were reported. The individuals of these populations were described by previous literature as T. cavicola or as Troglophilus sp. without species determination. In this work, an in situ morphological identification of all individuals detected in the surveyed caves, and a molecular identification on 12 specimens through the COI barcoding, were performed. An effective, fast, simple, economical and easily reproducible protocol for DNA extraction was optimized for this taxon. The presence of T. cavicola in the investigated area was confirmed and the presence of T. neglectus was reported for the first time. These new data allowed us to hypothesize different scenarios about their dispersal route in Lombardy. Moreover, these new findings must be considered to define sampling plans to elucidate the biogeography of this genus. [ABSTRACT FROM AUTHOR]

In the Lessini Mountains, the southernmost prealpine area in the Veneto region, thousands of caves are found, many of which have been extensively studied from the biological point of view. Numerous studies have been carried out on taxonomic and biogeographic aspects over the last hundred years. Two caves, in particular, have been found to be extremely rich in species adapted to life in subterranean environments. These are the Arena Cave in the Monti Lessini Veronesi and the Buso della Rana cave system in the Monti Lessini Vicentini. The two caves have extremely different development: Arena Cave is about 100 meters in length, and the Buso della Rana-Pisatela cave system is more than 37 km in length. Despite this huge difference in size, they both have the highest number of subterranean dwelling species in northern Italy (16 troglobionts and 8 stygobionts in Arena Cave, and 7 troglobionts and 11 stygobionts in the Buso della Rana-Pisatela cave system). [ABSTRACT FROM AUTHOR]

Cave-dwelling animals can be classified based on their occurrence in and relationship to the subterranean environment. Subsurface distribution data and studies addressing the initial causes for animals to enter underground habitats are sparse. By retrieving occurrence data from two voluntary biospeleological collections in Central Germany, the degree of cave penetration in terrestrial gastropods was investigated, thus to infer potential evolutionary drivers. In total, 66 identified gastropod species entered the subterranean environment with 23 of the species also recorded from the dark zone. Gastropods possessed variable degrees of cave penetration and no obligate cave forms were observed. A decline of occurrence records from the entrance to the dark zone was the most prominent pattern. Nevertheless, several species were collected from all three light zones (i.e. entrance, transition and dark). A variety of potential reasons can be inferred to explain their subsurface appearance: exploitation of alternative food sources, aphotic above-ground movement, mating sites, temporal, seasonal and long-term refugia, and chance. Moreover, the results imply a frequent migration of species between the interconnected light zones and the surface. Consequently, terrestrial gastropods should be considered when investigating the origin and importation of allochthonous resources in caves. [ABSTRACT FROM AUTHOR]

Due to their high economic value, karstic areas and caves have been affected for decades in Brazil. Accordingly, such systems have been receiving the attention of managers, environmental agencies and researchers, especially in recent years. The present study collected information regarding the cave invertebrate fauna of the Northwest region of Minas Gerais, Brazil, such as species richness and endemisms, besides the impacts and threats occurring in these environments, identifying caves and more vulnerable areas and proposing conservation actions. Three caves were identified as a priority for conservation: Lagoa Rica cave in Paracatu, and Lapa Nova and Lapa da Delza caves in Vazante. Another three areas were considered in need of conservation actions: regions of Arinos, Paracatu and Cabeceira Grande/Unaí. The main threat found in the area was the conversion of forests into pastures for cattle breeding, registered in the surroundings of 85% of the caves. The main recommendations were the recuperation of the surroundings, awareness raising of the population and biospeleological inventories in other caves of the area. The studied caves were very heterogeneous, presenting unique characteristics. Thus, the study of the highest possible number of caves of the region of interest is always recommended, to aid in conservation and action plans for cave fauna. [ABSTRACT FROM AUTHOR]

Ramón Margalef proposed in 1968 that ecosystems could be better understood if they were viewed as cybernetic systems. I tested this hypothesis in the case of hypogean ecosystems using available pieces of evidence. I looked on how information on feedbacks, stability, succession, organization, diversity, and energy flows in the hypogean environment fit the cybernetics hypothesis. The results were that there are convincing arguments that the application of the concept of cybernetics in biospeleology can be beneficial to broadening our understanding of cave biota in terms of their structure. I also make the case that this approach can provide more clarity about how cave biota has evolved through time and the implications for their conservation.

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.

The presence of mycobacteria was studied in Bull Rock Cave ("Byci skala") and the water catchment area of Jedovnice Brook ("Jedovnicky potok") using direct microscopy after Ziehl-Neelsen (ZN) staining, culture examination and molecular techniques. Mycobacteria were detected in 47.1% of a total of 68 samples. The mycobacterial genes hsp65 and dnaA were detected and sequenced in 37 (74.0%) out of the 50 cave environmental samples and in 10 (55.6%) out of the 18 samples of water catchment sediments. Nine species of slowly growing mycobacteria (M. terrae, M. arupense, M. gordonae, M. lentiflavum, M. parascrofulaceum, M. parmense, M. saskatchewanense, M. simiae and M. xenopi) and two subsp. (M. avium subsp. avium and M. avium subsp. hominissuis) were detected. Fourteen species of rapidly growing mycobacteria (M. chelonae, M. chubuense, M. poriferae, M. flavescens, M. fortuitum, M. porcinum, M. rhodesiae, M. gilvum, M. goodii, M. peregrinum, M. mageritense, M. vanbaalenii, M. gadium and M. insubricum) were detected. The highest mycobacterial presence was documented by ZN staining and/or culture examinations in earthworm castings and bat guano (73.3% positivity out of the 15 samples) in the cave environment and in the water sediments collected under the outflow from the wastewater treatment plants (77.8% positivity out of nine samples). The highest total organic carbon (TOC) was detected in wooden material and earthworm castings with pH values between 5.0 and 7.7 in the cave environment and in water sediments collected under the outflow from the wastewater treatment plants with pH between 5.8 and 7.0. It could be concluded that the karst cave environment with its running surface water contaminated with different microorganisms or chemical substances creates favourable conditions not only for animals (especially earthworms) but also for mycobacteria. This fact is also demonstrated by the presence of these mycobacteria in the cave environment mainly in earthworm castings and bat guano.

A new species of Eupolybothrus Verhoeff, 1907 discovered in caves of Velebit Mountain in Croatia is described. E. liburnicus sp. n. exhibits a few morphological differences from its most similar congeners, all of which are attributed to the subgenus Schizopolybothrus Verhoeff, 1934, and two approaches to species delimitation using the COI barcode region identify it as distinct from the closely allied E. cavernicolus Stoev & Komerički, 2013. E. spiniger (Latzel, 1888) is redescribed and a lectotype is designated for it as well as E. caesar (Verhoeff, 1899) to stabilize their respective taxonomic status. The subspecies E. acherontis wardaranus Verhoeff, 1937, previously suspected to be a synonym of E. caesar (Verhoeff, 1899), is redescribed and its taxonomy revised after the study of type material whereas the identity of E. acherontis (Verhoeff, 1900) described from a female from southwest Trebinje (Bosnia and Herzegovina) remains unknown. Type material of E. stygis (Folkmanova, 1940) is confirmed to be lost and future designation of neotypes from topotypic specimens is necessary to stabilize its taxonomy. The importance of setal arrangement on the intermediate and 14th tergites and the sexual modifications on the male 15th prefemur for species identification is discussed in the light of present findings, and a review of the species of E. (Schizopolybothrus) that display these traits is also provided. [ABSTRACT FROM AUTHOR]

Caves and cave-dwelling biota have fascinated scientists for centuries. Nevertheless, there is a considerable lack of information on subterranean realms and the ecosystems they host. Nematoda, for example, is a group of invertebrates that plays an important role in the functioning of epigean ecosystems, but whether or not the same is true for subterranean ecosystems remains unknown. For this reason it was decided to conduct an in-depth review of all reports related to cave-dwelling nematodes in order to provide a sound basis for future studies. A literature survey of 41 scientific works from over the last 138 years revealed 295 unique taxa reported from 78 different cave systems. The historical trends in cave nematology, peculiar findings from important studies and an ecological classification system are discussed. Lastly, the trophic distribution of the reported taxa is presented, whilst nematodes from other (non-cave) subterranean environments are also considered. [ABSTRACT FROM AUTHOR]