Sexual dimorphism in subterranean amphipod crustaceans covaries with subterranean habitat type.

Sexual dimorphism can evolve in response to sex-specific selection pressures that vary across habitats. We studied sexual differences in subterranean amphipods Niphargus living in shallow subterranean habitats (close to the surface), cave streams (intermediate), and cave lakes (deepest and most isolated). These three habitats differ because at greater depths there is lower food availability, reduced predation, and weaker seasonality. Additionally, species near the surface have a near-even adult sex ratio (ASR), whereas species from cave lakes have a female-biased ASR. We hypothesized (a) a decrease in sexual dimorphism from shallow subterranean habitats to cave lake species because of weaker sexual selection derived from changes in the ASR and (b) an increase in female body size in cave lakes because of stronger fecundity selection on account of oligotrophy, reduced predation, and weaker seasonality. We measured body size and two sexually dimorphic abdominal appendages for all 31 species and several behaviours related to male competition (activity, risk-taking, exploration) for 12 species. Species with an equal ASR that live close to the surface exhibited sexual dimorphism in all three morphological traits, but not in behaviour. The body size of females increased from the surface to cave lakes, but no such trend was observed in males. In cave lake species, males and females differed neither morphologically nor behaviourally. Our results are consistent with the possibility that sexual and fecundity selection covary across the three habitats, which indirectly and directly, respectively, shape the degree of sexual dimorphism in Niphargus species.

The behavioural costs of overcrowding for gregarious cave-dwelling bats.

Bats are known for their gregarious social behaviour, often congregating in caves and underground habitats, where they play a pivotal role in providing various ecosystem services. Studying bat behaviour remains an underexplored aspect of bat ecology and conservation despite its ecological importance. We explored the costs and impacts of overcrowding on bat social behaviour. This study examined variations in bat behavioural patterns between two distinct groups, aggregated and non-aggregated male Rousettus amplexicaudatus, within the Monfort Bat Cave Sanctuary on Mindanao Island, Philippines. We found significant variations in the incident frequencies of various bat behavioural activities, particularly aggression and movement, between these two groups. The increase in aggregation was closely related to negative social behaviour among bats. In contrast, sexual behaviour was significantly related to the positive behaviour of individual bats and was headed in less crowded areas. The disparities in bat behaviour with an apparent decline in bat social behaviour because of overcrowding, with more aggressive behaviours emerging, align with the 'behavioural sink' hypothesis. Our study underscores the importance of considering habitat quality and resource availability in the management and conservation of bat colonies, as these factors can reduce the occurrence of aggressive and negative social behaviours in colonies with high population density by providing alternative habitats.

Microplastic pollution calls for urgent investigations in stygobiont habitats: A case study from Classical karst.

Microplastic pollution in karst systems is still poorly studied, despite the presence of protected species and habitats, and important water reserves. Vulnerable key species hosted in these habitats could consume or assimilate microplastics, which can irreversibly damage management efforts, and thus ecosystems functionality. This can be particularly true for subterranean water habitats where microplastic pollution effects on wildlife management programs are not considered. The aim of this study is to provide a case study from the Classical Karst Region, which hosts peculiar habitats and key species protected at European level, such as the olm Proteus anguinus. As this area has been deeply exploited and modified over time, and is adjacent to highways, roads and railways, which could contribute to pollution within the karst system, threatening the ecosystems, it provides a perfect model system. In this study we collected and investigated water and sediment samples from aquatic environments of surface and subterranean habitats hosting several subterranean environment-adapted organisms. Examined particles were counted and characterized by size, color and shape via visual identification under a microscope, with and without UV light. Furthermore, spectroscopic analyses were carried out in order to identify microplastics typology. Microplastics were found in all examined habitats. In water, microplastics concentration ranged from 37 to 86 items/L, in sediments from 776 to 2064 items/kg. Fibre-shape was the main present, followed by fragments and beads, suggesting multiple sources of pollution, especially textile products. Most of the particles were fluorescent under UV light and were mainly transparent, while not-fluorescent ones were especially black, blue or brown. Samples contained especially polyesters and copolymers. These results highlight intense MP pollution in karst areas, with significant impacts on water quality, and potential effects on subterranean environment-dwelling species. We stress the importance of monitoring pollution in these critical environments for biodiversity and habitat conservation: monitoring in karst areas must become a priority for habitat and species protection, and water resources management, improving analyses on a larger number of aquatic surface and subterranean habitats.

Gastrointestinal parasitic helminths of bats from a cave in Luzon Island, Philippines.

Bats are often associated with several zoonotic diseases, including helminth infections. Despite their potential detrimental effects on both human and bat populations, information on helminth parasites of Philippine bats remains scarce. Here, we identify gastrointestinal helminths parasitizing bats collected from a cave complex in Cavinti, Laguna Province, Philippines, determine their prevalence (P) and mean intensity (MI), and investigate relationship of helminth prevalence and intensity with bat host characteristics including sex, diet, age, and roosting habit. We isolated 581 individuals of helminths representing six taxa (three trematodes, two nematodes, one cestode) from the gastrointestinal tract of sampled bats. Helminths were observed in 82 out of 172 bats captured (P = 47.67%), with Miniopteruspaululus having the highest infection rate (P = 91.3%) and highest MI (18 ± 4.5/infected bat). Helminths parasitizing endemic bat species from the Philippines, such as Rhinolophus rufus, Rhinolophus inops, Hipposideros pygmaeus, and Ptenochirus jagori were reported here for the first time. We provide new host records for other helminth species and report the presence of two parasites, Plagiorchis sp. and Toxocara sp., known for their zoonotic potential. These data will contribute to efforts in identifying parasites and diseases harbored by bats in the country and develop additional conservation measures for bats.

A molecular phylogeny of the European nesticid spiders (Nesticidae, Araneae): Implications for their systematics and biogeography.

Nesticidae is a small family of spiders with a worldwide distribution that includes 15 genera and 272 described species. Seven genera and 56 species are known from Europe, distributed from the Iberian Peninsula to the Caucasus and the Ural Mountains. Most of these European species are cave dwellers and many of them are troglobites. In this study we present the first molecular phylogeny of the family Nesticidae in Europe with a wide geographical sampling across the continent. In our analysis the European nesticid fauna is well represented, including six genera and 40 of the 56 currently accepted species including the type species of all sampled genera. We have included in the analysis representatives of the North American and Asian fauna to test the monophyly of the European species and the phylogenetic relationships of European lineages. Phylogenetic relationships were reconstructed using maximum likelihood and Bayesian inference. As part of our Bayesian analyses, we also dated the phylogeny using two approaches, one based only on fossil calibrations and one that included an additional biogeographical constraint. Our results show paraphyly of the European nesticids with respect to the Asian and North American taxa. We recover four main lineages within Europe. These four European lineages and all European genera have 100% bootstrap support and high posterior probability support in the BEAST2 analysis. The Typhlonesticus lineage is the earliest branching clade present in Europe and includes seven species, the five currently accepted species plus T. parvus from Bosnia and Herzegovina and T. silvestrii from western North America. The Eastern lineage includes the genus Aituaria and is the sister group of the Asian genera Nesticella and Wraios. The Domitius lineage is likely the sister group of the Central European lineage and spreads over the Iberian and Italian peninsulas. Finally, the Central European lineage includes three genera: Kryptonesticus, distributed from the karstic massifs of the Balkan Peninsula to Turkey, Nesticus with a single synanthropic species N. cellulanus and Carpathonesticus, exclusive to the Carpathian Mountains. With the exception of the genus Typhlonesticus, all European genera show an allopatric distribution (except for the two European synanthropic species). The results obtained in this study together with the revision of the original descriptions, redescriptions, and illustrations, lead us to propose 11 nomenclatural changes (new combinations) concerning the genera Typhlonesticus, Nesticus and Carpathonesticus.

In the land of the blind: Exceptional subterranean speciation of cryptic troglobitic spiders of the genus Tegenaria (Araneae: Agelenidae) in Israel.

Caves have long been recognized as a window into the mechanisms of diversification and convergent evolution, due to the unique conditions of isolation and life in the dark. These lead to adaptations and reduce dispersal and gene flow, resulting in high levels of speciation and endemism. The Israeli cave arachnofauna remains poorly known, but likely represents a rich assemblage. In a recent survey, we found troglophilic funnel-web spiders of the genus Tegenaria in 26 caves, present mostly at the cave entrance ecological zone. In addition, we identified at least 14 caves inhabited by troglobitic Tegenaria, which are present mostly in the twilight and dark ecological zones. Ten of the caves, located in the north and center of Israel, are inhabited by both troglophilic and troglobitic Tegenaria. These spiders bear superficial phenotypic similarities but differ in the levels of eye reduction and pigmentation. To test whether these taxa constitute separate species, as well as understand their relationships to epigean counterparts, we conducted a broad geographic sampling of cave-dwelling Tegenaria in Israel and Palestine, using morphological and molecular evidence. Counterintuitively, our results show that the troglobitic Tegenaria we studied are distantly related to the troglophilic Tegenaria found at each of the cave entrances we sampled. Moreover, seven new troglobitic species can be identified based on genetic differences, eye reduction level, and features of the female and male genitalia. Our COI analysis suggest that the Israeli troglobitic Tegenaria species are more closely related to eastern-Mediterranean congeners than to the local sympatric troglophile Tegenaria species, suggesting a complex biogeographic history.

A multidisciplinary approach to the comparison of three contrasting treatments on both lampenflora community and underlying rock surface.

Removing lampenflora, phototrophic organisms developing on rock surfaces in tourist cavities due to the artificial lighting, is a challenge for sustainable and appropriate long-term management of caves. Photosynthetic-based biofilms usually cause rock biodeterioration and an ecological imbalance in cave ecosystems. In this work, a detailed investigation of the effects of the 3 most commonly used lampenflora cleaning operations (NaClO, H2O2 and UVC) was carried out in Pertosa-Auletta Cave (Italy). The application of NaClO showed good disinfection capability over extended periods of time without causing any appreciable rock deterioration. The H2O2 treatment showed to be corrosive for the rock surfaces covered with vermiculation deposits. The chemical alteration of organic and inorganic compounds by H2O2 did not remove biomass, favoring biofilm recovery after three months of treatment. Both NaClO and H2O2 treatments were effective at removing photoautotrophs, although the bacterial phyla Proteobacteria and Bacteroidetes as well as Apicomplexa and Cercozoa among the Eukaryotes, were found to be resistant to these treatments. The UVC treatments did not show any noticeable effect on the biofilms.

A Q fever outbreak among visitors to a natural cave, Bizkaia, Spain, December 2020 to October 2021.

We describe a large Q fever outbreak reported in Spain, including 108 cases, 53 with pneumonia and 27 requiring hospitalisations. The first cases were detected in February 2021 among rock climbers visiting a cave in Bizkaia, and the last case was detected in October 2021. Most cases were notified after the Easter holiday (April-May 2021). More males (63.9%) than females (36.1%) were infected (median ages: 42 (1-68) and 39 years (6-61), respectively). We detected Coxiella burnetii by PCR in faecal, dust and/or aerosol samples taken inside the cave in March 2021, and in dust and aerosol samples collected between March 2021 and February 2023. Coxiella burnetii from dust samples were cultured on Vero cells, showing viability for 24 months. Based on serological and genotyping data, goats sheltering in the cave were the most likely source of infection. The cave was closed on 29 April 2021, movements of goats and sheep in the area were restricted (March-July 2021), and the animals were vaccinated in October 2021. Investigation of Q fever outbreaks requires a multidisciplinary One Health approach as these outbreaks can occur in unexpected places like natural sites where animals are present.

A Hansel & Gretel breadcrumb-style dynamically deployed communication network paradigm using mesh topology for planetary subsurface exploration.

We introduce a dynamically deployed communication network (DDCN) paradigm using mesh topology in support of a distributed robotic multi-agent approach for the autonomous exploration of subsurface environments, i.e., caves, lava tube caves, lakes, and oceans, etc. The DDCN, comprising wireless communication beacons autonomously deployed via a rover or submersible in a Hansel & Gretel-inspired breadcrumb style, allows for the longest and most robust communication link between subterranean robotic agent(s) within, e.g., a lave tube cave or a subsurface ocean, and associated surface-borne robotic agent(s). Moreover, we briefly touch on the development of a robotic testbed and wired/wireless communication beacons in support of such astrobiological surface/subsurface exploration scenarios. Candidate lava tube caves have been identified on the Moon and Mars, raising possibilities for planetary exploration, astrobiology, habitat construction for future astronauts, and potential mining operations. Subterranean caverns, and in particular relatively deep lava tube caves, provide a possible refuge for life under otherwise challenging planetary surface conditions, and, as such, are of prime astrobiological relevance. Lava tube caves or other subsurface environments may also be suitable habitats for astronauts and subsequent human settlement but are yet to be explored in part due to difficulties ensuring continued communication with a robotic probe inside these environments. Moreover, the existence of subsurface oceans on ocean worlds, such as Europa, Enceladus, and Titan, has been backed by varying levels of evidence since the 1980s, though there has been no confirmation, i.e., direct observation, thus far. Such environments are also shielded from radiation, and, in combination with the hypothesized presence of water, are additional candidate environments for finding extant or fossilized life. The DDCN paradigm introduced herein directly addresses NASA's Space Technology Grand Challenges - "All Access Mobility" by enabling the most unconstrained exploration of subsurface environments through a dynamic communication network which ensures transmission of data from and possibly commands to the subsurface robotic probe. 2023 COSPAR. Published by Elsevier B.V. All rights reserved.

Characteristics of submerged and partially submerged caves (habitat type 8330) in Romania.

Underwater sea caves form a relatively under-examined habitat type within the marine regions of Europe, although they provide unique physical conditions such as reduced light and wave energy, in addition to reduced temperature amplitude. This study aimed at revealing the characteristics of submerged cavities on the southern Romanian continental shelf where six protected areas exist. We used high-resolution bathymetry data and side-scan sonar imaging to identify limestone outcrops where cavities would be most probable to form and then performed visual observation during SCUBA diving activities. We found that submerged cavities appear in all marine-protected areas and their neighboring unprotected areas from the shore to ~20-m depth mostly in the form of caverns, niches, and overhangs that meet the physical requirements of the habitat type 8330 as defined by the European Commission. We propose that habitat type 8330 should be listed in the Natura 2000 Standard Data Forms of the protected areas where it is missing, and we also propose that some protected areas should be expanded to include important areas with the occurrence of this habitat type. Finally, we note here for the first time the occurrence of Movile-type karst and an associated sulfidic water spring on the southern shore of Lake Techirghiol, similar to the region near Mangalia where it was first described in the literature. Although our finding prompts for a more detailed study, it indicates the existence of an underground ecosystem similar to that from the well-studied Movile Cave, but isolated by a distance of over 20 km.

Unravelling unknown cyanobacteria diversity linked with HCN production.

Cyanobacteria are ecologically versatile microorganisms, occupying diverse habitats, from terrestrial caves to coastal shores and from brackish lakes to thermal springs. Cyanobacteria have also been linked with hydrogen cyanide (HCN), mainly for their ability to catabolize HCN by the nitrogenase enzyme. In this context, we sampled disparate environments, spanning from Canary Islands and Iceland to Estonia and Cyprus. Eighty-one (81) strains were isolated and characterised with taxonomic indices and molecular markers (16S-23S rRNA region and cpcBA region), whilst their ability to produce HCN was evaluated. This approach resulted in the description of five new genera (Speleotes, Haliplanktos, Olisthonema, Speos, and Iphianassa) and their type species (S. anchialus, H. antonyquinny, O. eestii, S. fyssassi, I. zackieohae) representing Chroococcales, Chroococcidiopsales, Oscillatoriales, Synechococcales, and Nostocales orders, respectively. We also found unique lineages inside the genera Komarekiella, Stenomitos, Cyanocohniella, and Nodularia, describing four new species (K. chia, S. pantisii, C. hyphalmyra, N. mediterannea). We report for the first time a widespread production of HCN amongst different taxa and habitats. Epilithic lifestyle, where cyanobacteria are more vulnerable to grazers, had the largest relative frequency in HCN production. In this work, we show novel cyanobacteria diversity from various habitats, including an unexplored anchialine cave, and possible correlation of cyanobacteria chemo- with species diversity, which may have implications on strategic focusing of screening programs on underexploited taxa and/or habitats.

New records of soft ticks (Acari: Argasidae) in the Caatinga biome of Brazil, with a phylogenetic analysis of argasids using the nuclear Histone 3 (H3) gene.

In Brazil, 19 species of the genus Ornithodoros (Acari: Argasidae) have been reported. The medical and veterinary importance of Ornithodoros ticks has increased substantially in recent decades, with the discovery of various relapsing fever Borrelia infecting Ornithodoros ticks. Herein, argasid ticks were collected during 2019-2020 from caves, abandoned nests and homes in various regions of Ceará State, Brazilian semiarid-Caatinga biome. In total, 289 ticks were collected and identified into five species: Ornithodoros cavernicolous (176 specimens), Ornithodoros fonsecai (81), Ornithodoros mimon (12), Ornithodoros rietcorreai (4), and a fifth species provisionally retained as Ornithodoros sp. Ubajara. Tick identifications were corroborated by a phylogenetic analysis inferred using the 16S rRNA gene. To extend the molecular characterization, DNA samples were tested by an additional PCR assay targeting the nuclear Histone 3 (H3) gene. Because there were no H3 sequences of argasids in GenBank, we extended this PCR assay for additional Ornithodoros species, available in our laboratory. In total, 15 partial sequences of the H3 gene were generated for 10 Ornithodoros species, showing 0% intraspecific polymorphism, and 1.5-11.6% interspecific polymorphism. Phylogenetic analyses inferred segregated Ornithodoros sp. Ubajara as a potential novel species. Our results also highlight the potential of the H3 gene for deeper phylogenetic analyses of argasids. The present study provides new data for argasid ticks of the genus Ornithodoros in the Caatinga biome. Because some of these tick species are human-biting ticks, active surveillance for the incidence of human infection due to Ornithodoros-borne agents is imperative in the Caatinga biome.

Underground Ecosystem Conservation Through High-resolution Air Monitoring.

In cave ecosystems tourists represent moving sources of discontinuous disturbances, able to induce transient system responses whose knowledge is crucial in defining appropriate conservation measures. Here we propose an approach to evaluate the amplitude and scales of cave alterations based on high-resolution air monitoring, through the use of purposely developed low-cost monitoring stations and a consistent analytical framework for information retrieval based on time series analysis. In particular, monitoring stations adopt a modular structure based on physical computing platforms acquiring data through several sensors, with means of preventing humidity damages and guaranteeing their continuous operation. Data are then analyzed using wavelet periodograms and cross-periodograms to extract the scales of tourism-induced alterations. The approach has been exemplified in the Pertosa-Auletta Cave, one of the most important underground environments in Southern Italy, highlighting the development of monitoring stations and the information obtainable with the proposed analytical workflow. Here, 2 monitoring stations acquiring data for 1 year at 1' sampling time on temperature, relative humidity, CO2, VOCs, and particulate matter were deployed in trails subjected to different levels of tourism. In terms of Pertosa-Auletta Cave air dynamics, the approach allowed estimating the temporal and spatial scales of tourism-induced alterations in the order of minutes and meters, respectively, with parameter-dependent variations. On more general terms, the approach proved reliable and effective, with its modularity and low-cost fostering its straightforward adoption in other underground ecosystems, where it can support the development of tailored management strategies.

Stronger together: understanding and protecting karst resources.

The United Nations Educational, Scientific, and Cultural Organization (UNESCO) has recognized more than 350 karst areas of global importance through various designations (Biosphere Reserve, World Heritage Sites, Ramsar Sites, and Global Geoparks) with at least one UNESCO protected area with karst in 86 countries (Gunn 2020). In August 2020, Western Kentucky University, the George Wright Society, and the UNESCO Mammoth Cave Biosphere Region hosted Conservation of Fragile Karst Resources: A Virtual Workshop on Sustainability and Community in support of UNESCO science programs. The purpose of this meeting was to enhance communication and the sharing of ideas and resources between major conservation and science programs that protect, study, or manage cave and karst resources, with particular interest to those of international significance. This special issue is published in celebration and support of the UIS International Year of Caves and Karst and as a call-to-action to better explore, understand, and protect the value of cave and karst areas to humanity in both our everyday lives as well as our natural and cultural heritage.

The Zadek calcaneal osteotomy in Haglund's syndrome of the heel: Clinical results and a radiographic analysis to explain its efficacy.

Local debridement or decompression of the posterior heel in Haglund's syndrome yields variable results. This condition is sometimes due to an excessively long calcaneus rather than simply a large posterosuperior bony prominence. Failure to address this abnormality may explain the poor results in some series. We recently published a new measurement (the X/Y ratio) which, combined with the calcaneal pitch angle, assesses the abnormality of the shape of the calcaneus. The Zadek osteotomy strongly modifies that shape. We retrospectively reviewed 50 patients treated by a Zadek osteotomy at a mean 7 years follow-up using the AOFAS ankle-hindfoot score, the VISA-A score and Tegner scale. We measured only the X/Y ratio and the calcaneal inclination angle, as the classically described radiographic measurements in Haglund's syndrome are unreliable. We then assessed the condition of the distal end of the Achilles tendon with an MRI. Our results demonstrate excellent outcomes(40/50, 80%) following Zadek osteotomy and correspond to the change in pre- and post-operative measurements, especially the X/Y ratio. An algorithm using those geometrical measurements of the calcaneus is proposed for decision making in Haglund's syndrome. Level of clinical evidence: Level 3.

Lighting Effects on the Development and Diversity of Photosynthetic Biofilm Communities in Carlsbad Cavern, New Mexico.

Photosynthetic cave communities ("lampenflora") proliferate in Carlsbad Cavern and other show caves worldwide due to artificial lighting. These biofilms mar the esthetics and can degrade underlying cave surfaces. The National Park Service recently modernized the lighting in Carlsbad Cavern to a light-emitting diode (LED) system that allows adjustment of the color temperature and intensity. We hypothesized that lowering the color temperature would reduce photopigment development. We therefore assessed lampenflora responses to changes in lighting by monitoring photosynthetic communities over the course of a year. We measured photopigments using reflected-light spectrophotometric observations and analyzed microbial community composition with 16S and 18S rRNA gene amplicon sequencing. Reflected-light spectrophotometry revealed that photosynthetic biofilm development is affected by lighting intensity, color temperature, substrate type, and cleaning of the substrate. Gene sequencing showed that the most abundant phototrophs were Cyanobacteria and members of the algal phyla Chlorophyta and Ochrophyta At the end of the study, visible growth of lampenflora was seen at all sites. At sites that had no established biofilm at the start of the study period, Cyanobacteria became abundant and outpaced an increase in eukaryotic algae. Microbial diversity also increased over time at these sites, suggesting a possible pattern of early colonization and succession. Bacterial community structure showed significant effects of all variables: color temperature, light intensity, substrate type, site, and previous cleaning of the substrate. These findings provide fundamental information that can inform management practices; they suggest that altering lighting conditions alone may be insufficient to prevent lampenflora growth.IMPORTANCE Artificial lighting in caves visited by tourists ("show caves") can stimulate photosynthetic algae and cyanobacteria, called "lampenflora," which are unsightly and damage speleothems and other cave surfaces. The most common mitigation strategy employs bleach, but altering intensities and wavelengths of light might be effective and less harsh. Carlsbad Cavern in New Mexico, a U.S. National Park and UNESCO World Heritage Site, has visible lampenflora despite adjustment of LED lamps to decrease the energetic blue light. This study characterized the lampenflora communities and tested the effects of color temperature, light intensity, rock or sediment texture, and time on lampenflora development. DNA amplicon sequence data show a variety of algae and cyanobacteria and also heterotrophic bacteria. This study reveals microbial dynamics during colonization of artificially lit surfaces and indicates that while lowering the color temperature may have an effect, management of lampenflora will likely require additional chemical or UV treatment.

No room for males in caves: Female-biased sex ratio in subterranean amphipods of the genus Niphargus.

Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a data set of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing an environmental gradient of increased isolation underground. The ASR was female-biased in 27 of 35 species; the bias was statistically significant in 12 species. We found a significant difference in the ASR among habitats after correction for phylogeny. It is most weakly female-biased at the surface-subterranean boundary and most strongly female-biased in phreatic lakes. Additional modelling suggests that the ASR has evolved towards a single value for both surface-subterranean boundary and cave stream-dwelling species, and another value for 9 of 11 phreatic lake dwellers. We suggest that a history of inbreeding in subterranean populations might lower inbreeding depression such that kin selection favours mating with siblings. This could select for a female-biased offspring sex ratio due to local mate competition among brothers. The observed patterns in sex ratios in subterranean species make them a group worthy of more attention from those interested in sex allocation theory.

Karst terrain in the western upper Galilee, Israel: Speleogenesis, hydrogeology and human preference of Manot Cave.

A karst survey of the western upper Galilee in Israel shows that karst has been a dominant geomorphic factor throughout the Cenozoic. We discuss the geomorphic character of Manot Cave on the background of other karst features of the region, in order to decipher the preferences of the humans who favored this cave over others. Tens of caves distributed over the study area demonstrate that phreatic and hypogene isolated voids and conduit segments are more abundant than vadose shafts, sinking stream caves and spring caves, although all these types are present. Most caves belong to old stages of landform development, prior to Plio-Pleistocene uplift and stream entrenchment. Manot Cave is a relict chamber cave, which corresponds to a plaeo-water table and the erosion plain above it. Subaerial denudation and slope processes have opened the cave to the surface during the mid-late Pleistocene. Manot Cave is compared with other caves in the region, demonstrating its unique character. It may have been selected due to the small entrance facing to the SW, and the large inner chamber which could be used for non-domestic purposes. This suggests a possible role of a unique behavioral and cultural suite of characters which influenced hominin preferences. The cave was used by hominins and animals until being closed again by colluvium and possibly collapse, ∼30 ka. Clastic, chemical, archaeozoological and anthropogenic accumulations reflect the various stages of cave development and gradual sealing of the entrance.

Morphological malleability of the lateral line allows for surface fish (Astyanax mexicanus) adaptation to cave environments.

The lateral line is the primary modality fish use to create a hydrodynamic image of their environment. These images contribute to a variety of behaviors, from rheotaxis to escape responses. Here we discern the contributions of visual and lateral line modalities in hunting behavior of larvae that have developed under different photic conditions. In particular, cave animals have a hypertrophied sense of mechanosensation, and we studied the common animal model cavefish Astyanax mexicanus and its closest related surface relative. We raised larvae in a diurnal light-dark regimen and in complete darkness. We then examined the distribution of neuromasts in their lateral lines, and their hunting performance in light and dark conditions, with and without the contribution of the lateral line. We report that all larva depend on the lateral line for success in hunting and that surface fish raised in the dark have a greater dependency on the lateral line.

Pseudomonas karstica sp. nov. and Pseudomonas spelaei sp. nov., isolated from calcite moonmilk deposits from caves.

A taxonomic study of two fluorescent Pseudomonas strains (HJ/4T and SJ/9/1T) isolated from calcite moonmilk samples obtained from two caves in the Moravian Karst in the Czech Republic was carried out. Results of initial 16S rRNA gene sequence analysis assigned both strains into the genus Pseudomonas and showed Pseudomonas yamanorum 8H1T as their closest neighbour with 99.8 and 99.7 % 16S rRNA gene similarities to strains HJ/4T and SJ/9/1T, respectively. Subsequent sequence analysis of rpoD, rpoB and gyrB housekeeping genes confirmed the highest similarity of both isolates to P. yamanorum 8H1T, but phylogeny and sequences similarities implied that they are representatives of two novel species within the genus Pseudomonas. Further study comprising whole-genome sequencing followed by average nucleotide identity and digital DNA-DNA hybridization calculations, repetitive sequence-based PCR fingerprinting with the REP and ERIC primers, automated ribotyping with the EcoRI restriction endonuclease, cellular fatty acid analysis, quinone and polar lipid characterization, and extensive biotyping confirmed clear separation of both analysed strains from the remaining Pseudomonas species and showed that they represent two novel species within the genus Pseudomonas for which the names Pseudomonas karstica sp. nov. (type strain HJ/4T=CCM 7891T=LMG 27930T) and Pseudomonas spelaei sp. nov. (type strain SJ/9/1T=CCM 7893T=LMG 27931T) are suggested.