Brazilian Caves Research Articles

Bats (Mammalia, Chiroptera) and bat flies (Diptera, Streblidae) found in the largest sandstone cave of Brazil

Abstract Bats provide essential ecosystem services and some are cave dependent. Caves favour the association of bats with ectoparasite Diptera, however, they are poorly sampled in the Amazon biome. Here we present the first description of a community of bats and bat flies from the largest sandstone cave in Brazil, the Planaltina cave, located in the municipality of Brasil Novo, state of Pará. Diptera were removed from captured bats and taken to the laboratory for identification. From nine species of bats belonging to four families we recorded 17 species of Diptera, 13 were monoxenous. A possible explanation for the monoxenous parasites collected is that flies have poor survival in unusual hosts. These results are an indicator that the Streblid species are host-specific since even if the hosts take refuge in the same cave, they will not share their parasites. Therefore, the present study provides important information on the parasite-host dynamics in a cave, thus highlighting the importance of cave as are essential shelters for bat species and, despite reported cases of cohabitation, mixed colonies are unlikely to form.

Two new species of Brazilian Johnstonianidae (Trombidiformes: Parasitengona)

Two new species, Newellia xakriaba sp. nov. and Centrotrombidium krenak sp. nov. (Trombidiformes: Parasitengona: Johnstonianidae) from Brazilian caves, are described based on vouchering material for which sequences from multiple genes are available. This article expands the geographical range of the genus Newellia André, 1962 known previously only from Angola.

Diversity and conservation of fishes from karstic areas of the Jandaíra Formation in the Brazilian semiarid

Few studies have focused on non-troglomorphic fishes occurring in Brazilian caves, especially those in the Caatinga region. The present study is the first survey of fishes from karstic areas of the Jandaíra Formation in Rio Grande do Norte State, northeastern Brazil. This region is characterized by a high concentration of caves and a rich subterranean biodiversity, especially of troglobitic invertebrates, but remains considered a gap on the knowledge of the subterranean ichthyofauna in Brazil. Four field expeditions were carried out covering two dry and two rainy seasons, in 2018 and 2019, in 23 localities in small river basins along the western part of the Jandaíra Formation. A total of 829 fish specimens, none of them troglomorphic, was captured and identified as belonging to 25 species of 12 families and five orders. Amongst them, four species are endemic of the Mid-Northeastern Caatinga ecoregion, and two non-native species were recorded. Habitats were classified into three categories: superficial, associated to cave, and cave. Although no troglomorphic fish species was found in this study, we recorded 64.1% of the Apodi-Mossoró river ichthyofauna occurring in caves or associated to caves, corroborating the hypothesis that part of the ichthyofauna exploits these environments as a refuge during the dry season. In addition, we suggest conservation policies for the maintenance of subterranean and aquatic semiarid ecosystems in the Jandaira formation, which is currently under threat due to anthropogenic activities, such as mining and deforestation.

Tudo é parecido, tudo é diferente! Trichorhina (Oniscidea, Platyarthridae) de cavernas brasileiras, com descrições de 11 novas espécies

Abstract The present work describes 11 new species of the genus Trichorhina from Brazilian caves in the states of Bahia, Mato Grosso do Sul, Minas Gerais, Pará, and São Paulo. Moreover, the distribution of T. tomentosa has been expanded to include the states of Mato Grosso and Minas Gerais. Additionally, a distribution map and a key for all Brazilian species of Trichorhina, including epigean ones, are provided.

Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species.

Caves are special environments that harbour an incredible diversity of life, including fungal species. Brazilian caves have been demonstrated to be biodiversity hotspots for known and unknown fungal species. We investigated the richness of culturable fungi in a tropical cave in Brazil by isolating these microorganisms from the sediment and air. The fungal abundance of colony-forming units (CFUs) was 3178 in sediment and 526 in air. We used morphological features and phylogenetic analyses of actin (actA), calmodulin (cmdA), internal transcribed spacer regions and intervening 5.8S rRNA (ITS), large subunit (LSU) rDNA, RNA polymerase II second largest subunit (rpb2), translation elongation factor 1-alpha (tef1), and β-tubulin (tub2) genes to identify these isolates. Forty-one species belonging to 17 genera of Ascomycota and two of Basidiomycota were identified, and the genus Aspergillus was most commonly observed in the cave (13 taxa). Twenty-four species were found in sediment (16 exclusives) and 25 species were found in air (17 exclusives). In this study, we introduced a new genus (Pseudolecanicillium gen. nov.) in the family Cordycipitaceae and six new species (14 % of the total taxa identified) of fungal isolates obtained from sediment and air: Aspergillus lebretii sp. nov., Malbranchea cavernosa sp. nov., Pseudohumicola cecavii sp. nov., Pseudolecanicillium caatingaense sp. nov., Talaromyces cavernicola sp. nov., and Tritirachium brasiliense sp. nov. In addition, we built a checklist of the fungal taxa reported from Brazilian caves. Our results highlight the contribution of Brazilian caves to the estimation of national and global fungal diversity. Citation: Alves VCS, Lira RA, Lima JMS, Barbosa RN, Bento DM, Barbier E, Bernard E, Souza-Motta CM, Bezerra JDP (2022). Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species. Fungal Systematics and Evolution 10: 139-167. doi: 10.3114/fuse.2022.10.06.

High genetic connectivity among large populations of Pteronotus gymnonotus in bat caves in Brazil and its implications for conservation

Bat caves in the Neotropical region harbor exceptional bat populations (> 100,000 individuals). These populations play a wider role in ecological interactions, are vulnerable due to their restriction to caves, and have a disproportionate conservation value. Current knowledge of bat caves in Brazil is still small. However, systematic monitoring of some bat caves in northeastern Brazil shows that they experience strong population fluctuations over short periods of time, suggesting large-scale movements between roosts and a much broader use of the landscape than previously considered. Spatio-temporal reproductive connectivity between distant populations would change our understanding of the use of roosts among bat species in Brazil, and important gaps in knowledge of long-distance bat movements in the country would be filled. Here, we used ddRADseq data to analyze the genetic structure of Pteronotus gymnonotus across nine bat caves over 700 km. Our results indicate the lack of a clear geographic structure with gene flow among all the caves analyzed, suggesting that P. gymnonotus uses a network of bat caves geographically segregated hundreds of kilometers apart. Facing strong anthropogenic impacts and an underrepresentation of caves in conservation action plans worldwide, the genetic connectivity demonstrated here confirms that bat caves are priority sites for bat and speleological conservation in Brazil and elsewhere. Moreover, our results demonstrate a warning call: the applied aspects of the environmental licensing process of the mining sector and its impact must be reviewed, not only in Brazil, but wherever this licensing process affects caves having exceptional bat populations.

A new genus and two new species of chigger mites (Trombidiformes: Leeuwenhoekiidae) from Brazilian caves with notes about the genus Whartonia Ewing, 1944

ABSTRACT The family Leeuwenhoekiidae has a worldwide distribution. In Brazil, it is represented by five genera and 10 species parasitising all groups of terrestrial vertebrates. Examination of material housed in the Acari Collection of the Instituto Butantan revealed undescribed species belonging to this family. In the present study, we describe a new genus, Caramuruacarus gen. nov., with the type species Caramuruacarus carnavalesca sp. nov. from the Minas Gerais State and a new species for the genus Whartonia, Whartonia parauapebensis sp. nov., from Pará State, both from the soil of Brazilian caves. In addition, a discussion of the genus Whartonia and its subgenera is provided. http://www.zoobank.org/urn:lsid:zoobank.org:pub:B4D09A27-D163-4772-B4FA-79949D5FEC9F http://www.zoobank.org/urn:lsid:zoobank.org:pub:F3533B72-8643-467F-A348-63534EB67AAA http://www.zoobank.org/urn:lsid:zoobank.org:pub:3BC85F16-1E6D-4FFB-9B71-465A2689D9EE

Going Underground: What the Natural History Traits of Cave Users Can Tell Us about Cave Use Propensity

Amphibians and reptiles use caves in different lithologies and biomes. However, the ecological reasons for such behavior have so far not been investigated in a broad scale. We surveyed 945 Brazilian caves in three biomes (Caatinga, Cerrado, and the Amazon), from which 269 had frogs and reptiles. We classified species of amphibians (34) and reptiles (19) according to natural history traits including habit, activity, diet composition, foraging strategy, and developmental mode (anurans). We used IUCN species distribution maps to predict what species occur in the vicinities of the caves but did not use them to test whether specific life history traits were distributed differently between species using and not using caves. We also tested seasonality and occurrence of bodies of water inside caves used by anurans, as well as the area occupied by man-made building and infrastructure around caves as explanatory factors for cave use intensity. Anurans with direct development were more likely to use caves than those with a tadpole stage. Terrestrial anurans were more likely to use caves than arboreal and semiarboreal anurans. No fossorial, semifossorial, or semiaquatic species used caves. Among reptiles, sit-and-wait foragers were more likely to use caves than active foragers. Semiaquatic and terrestrial reptiles were the most likely to use caves. Anurans were most likely to use caves with perennial bodies of water and during the dry season. Our results indicate that species of the herpetofauna are likely to search for resources in the cave habitat as indicated by the relationship between specific life history traits and cave use.

Revisiting the cave-dwelling sand flies (Diptera, Psychodidae, Phlebotominae) from Brazil: Diversity and potential role in the transmission of Leishmania Ross, 1903 (Kinetoplastida: Trypanosomatidae).

Brazilian caves, one of the many tourist attractions of the country, may act as a shelter for insects, such as sand flies (Diptera: Psychodidae), natural hosts of various microorganisms including parasites of the genus Leishmania Ross, 1903. In the last decades, with the increasing global need for sustainable development, ecotourism has emerged as one of the major activities in Brazil. However, the constant monitoring in environmentally protected areas is not often carried out, endangering visitors and professionals, especially due to the occurrence of zoonoses. Several sand fly species have already been recorded in Brazilian caves, drawing attention to the possibility of Leishmania transmission at this ecotope. Indeed, this current systematic review summarizes the fauna of cave-dwelling sand flies in Brazil, focusing on their biological behaviour and the occurrence of potential vectors of Leishmania parasites.

A new species of Chaimowiczia from the karstic Serra do Ramalho plateau, Brazil (Oniscidea, Synocheta, Styloniscidae)

Chaimowiczia belongs to the subfamily Iuiuniscinae, family Styloniscidae, and is currently composed of two troglobitic species: C. tatus and C. uai, both occurring in Brazil. A new species of Styloniscidae found in Brazil (Bahia state, Serra do Ramalho, Serra Verde cave) was allocated into this genus by the antenna flagellum with three articles; rectangular-shaped lateral pereonites epimera not apically acute and apex of pleopod 2 endopod with an acute tip and an acute or rounded lobe directed outwards. The new species, C. obybytyrasp. nov., is here described and rises to 25 the number of troglobitic styloniscidean species known for Brazilian caves.

Estimates of insect consumption and guano input in bat caves in Brazil

Estimates of insect consumption and guano input in bat caves in Brazil

Two new larval species of Birjandtrombella (Neotrombidiidae) from Brazil

Two new larval species of Birjandtrombella minae sp. nov. and Birjandtrombella pataxo sp. nov., (Acari: Trombidiformes: Prostigmata: Neotrombidiidae) are described and illustrated from neotropical caves in Brazil (South America). The generic diagnosis of Birjandtrombella is modified and a key to larvae is presented.

Absolute configuration of cytotoxic anthraquinones from a Brazilian cave soil-derived fungus, Aspergillus sp. SDC28.

Microbial strains isolated from extreme and understudied environments, such as caves, are still poorly investigated for the production of bioactive secondary metabolites. Investigation of the ethyl acetate extract from the growth medium produced by the soil-derived fungus Aspergillus sp. SDC28, isolated from a Brazilian cave, yielded two anthraquinones: versicolorin C (1) and versiconol (2). The complete assignment of nuclear magnetic resonance and mass spectroscopic data of 1 and 2 was performed for the first time. Moreover, the yet unreported absolute configuration of both compounds was unambiguously established by analysis of experimental and theoretical electronic circular dichroism data. Vibrational circular dichroism was also applied to confirm the absolute stereochemistry of 2. Compounds 1 and 2 showed cytotoxic activity against human ovarian cancer cells (OVCAR3).

Two extraordinary troglobitic species of Allokoenenia (Eukoeneniidae: Palpigradi) from Brazil: first records of this initially monotypic genus more than a century after its description

The diversity of Palpigradi is not evenly distributed among its different branches. The widespread genus Eukoenenia includes 80% of the species, while the other genera are poorly known. Allokoenenia certainly is the most understudied genus because it is represented only by the African species Allokoenenia afra Silvestri, 1913. Its description is short and does not include many features depicted in modern taxonomy of Palpigradi. In this paper, we describe two troglobitic species of Allokoenenia, report the occurrence of a third species represented by an immature specimen from Brazilian caves, and provide brief notes on the morphology of A. afra. Allokoenenia canhembora sp. nov., A. stygia sp. nov., and Allokoenenia sp. differ from A. afra by several morphological features, including more elongated appendages and a greater number of blades on lateral organs. Thus, they are considered troglomorphic. These new species are vulnerable to extinction because they are endemic to a single or few caves directly impacted by mining activities and groundwater exploitation. This study represents the first step for the conservation of these species and their habitats, since Brazilian caves with rare troglobites cannot be irreversibly impacted. Also, it brings important contributions on the distribution and morphology of this enigmatic genus.

Unique and fragile diversity emerges from Brazilian caves – two new amphibious species of Xangoniscus Campos-Filho, Araujo & Taiti, 2014 (Oniscidea, Styloniscidae) from Serra do Ramalho karst area, state of Bahia, Brazil

Two new troglobitic species of Xangoniscus are described from two caves of Serra do Ramalho karst area, Bambuí geomorphological group, state of Bahia. Xangoniscus lapaensissp. nov. is described from Gruna Boca da Lapa cave, and X. loboisp. nov. from Gruna da Pingueira II cave. Both species are blind and depigmented and show amphibious habits, as observed for all species of Xangoniscus described until now. Xangoniscus lapaensissp. nov. occurs in travertine pools fed by water of the upper aquifer, and X. loboisp. nov. occurs in a small stream, an upper vadose tributary. Both species occur in fragile microhabitats. Ecological and behavioral data, conservation remarks, and IUCN conservation assessments are included to provide background data for conservation efforts in this unique karst area.

Scarabs in the dark: occurrence of Scarabaeoidea beetles (Insecta: Coleoptera) in Brazilian caves

Scarabeoidea (Insecta: Coleoptera) present more than 2000 species recorded from all over Brazil. They have been scarcely recorded from caves, and truly troglobitic species are yet to be found in the country. In this study, we carried out a review of all existing scarab beetles deposited until 2017 in the Coleção de Invertebrados Subterrâneos de Lavras (ISLA), at the Universidade Federal de Lavras (UFLA) (Minas Gerais, Brazil), one of the most important collections of subterranean invertebrates in South America. Ninety-two individuals belonging to 52 species were recorded, distributed in six families (Cetoniidae, Hybosoridae, Melolonthidae, Passalidae, Scarabaeidae and Trogidae). Scarabaeidae was the most diverse of them, representing more than 50% of the total of species recorded. We found Scarabeoidea beetles in 51 of the ~ 1600 caves examined, distributed in nine Brazilian states: Alagoas, Bahia, Distrito Federal, Espírito Santo, Goiás, Minas Gerais, Pará, Piauí, and Tocantins. Our results provide evidence that Scarabaeoidea beetles are not frequent in Brazilian caves, and their records in this kind of environment are mostly accidental. Exceptions include Trogidae and Aphodiinae species, which may be associated with bat guano. Our study presents the first list of Scarabaeoidea species sampled in Brazilian caves.

A karstic model of the generation of tablelands landscapes in sandstones in Eastern Amazonia

Tablelands are typical reliefs in many cratons of the world, particularly in the eastern portion of South America. Until recently, tablelands have been interpreted as resulting from initial superficial fluvial erosion that segmented wide plateaus and subsequent slope retreat that decreased plateau areas into smaller mesas and buttes. Based on morphological observations and isotopic measurements in sandstone caves in Brazil, we present an alternative scenario in which such sandstone landscapes may result from karst processes. This study relies on cosmogenic nuclide pair concentrations (10Be and 26Al) measured in river-borne, modern fluvial sediments, suggesting that these fluvial sediments may have actually undergone complex exposure-burial histories. Collapse of cave ceilings and associated karst processes in sandstones may thus represent an initial step responsible for the morphogenesis of the regional tablelands landscape. The widespread occurrence of similar karst geoforms in tablelands in several areas in eastern/northern South America suggests that this model may have a general implication.

A new species of Spelunconiscus (Isopoda: Oniscidea: Styloniscidae) for Brazilian caves: new record for the type species and an emended diagnosis for the genus

Spelunconiscus Campos-Filho, Araujo and Taiti, 2014 is a monotypic genus of the family Styloniscidae represented by a troglobitic species, Spelunconiscus castroi Campos-Filho, Araujo and Taiti, 2014, from the cave MOC-32, in the state of Minas Gerais, southeastern Brazil. New representatives of this family were found in three additional caves, which revealed a new species, Spelunconiscus septemlacuum sp. nov., from Taboa and Tatuzinhos caves and a new occurrence for the type-species in Retiro cave. The original diagnosis of Spelunconiscus is emended due to the discovery of a spur-like structure in the male pereopod VII ischium, as well as some supplementary traits that have not been previously considered. Spelunconiscus septemlacuum sp. nov. differs from S. castroi in the number of articles of the antennal flagellum, in the proportion between this flagellum and 5th article of peduncle of antenna, in the size of maxilliped endite, in the morphology of male pleopod II and in body size. A discussion is provided for both taxonomic and ecological concerns.

Bringing order to a complex system: phenotypic and genotypic evidence contribute to the taxonomy of Tityus (Scorpiones, Buthidae) and support the description of a new species.

We present a molecular phylogenetic analysis including a survey for overlooked phenotypic characters. Based on both analysis and characters a new cave-dwelling species is described: Tityus (Tityus) spelaeussp. nov. from the Russão II cave, Posse, state of Goiás, Central Brazil. Characters such as the glandular regions of the female pectinal basal piece and basal middle lamellae of pectines, and the distribution of the ventral setae of telotarsi I–IV proved to be useful to constructing the taxonomy of species and species groups of Tityus. The new species is a member of the Tityustrivittatus species-group of Tityus (Tityus) and can be readily recognized by the immaculate coloration pattern and the more developed glandular region on the female pectinal basal piece. In addition, we provide a discussion of the phylogenetic relationships observed within Tityus, on the relevance of the new phenotypic characters to the modern taxonomy of the genus Tityus, and to the records of Brazilian cave scorpions.

Potential of cave isolated bacteria in self-healing of cement-based materials

Cementitious materials suffer from cracking, decreasing their durability. As a solution, crack self-healing materials using CaCO3 precipitating bacteria began to be studied worldwide. This research aimed to select the environmental bacterium with the most significant self-healing potential among samples isolated from a Brazilian cave in the Amazon region, besides providing a better understanding of the genome and its influence in crystal precipitation. For this purpose, 11 bacteria were tested in vitro for CaCO3 precipitation, using B4 medium (0.4% yeast extract, 0.5% glucose and 0.25% calcium acetate). The bacterium with the most significant precipitation potential was analyzed by SEM and EDS. Moreover, complete genome sequencing (CGS) was carried out for a better understanding of the precipitation mechanism. Afterward, a preliminary test was performed in mortars with cave-isolated bacteria to analyze self-healing ability and compressive strength. Besides that, the precipitated crystals were analyzed by XRD and SEM. The results showed that B. subtilis CV16 strain, isolated from a cave in the Oriental Amazon (Brazil), presented the most significant capacity of CaCO3 precipitation among the tested ones. Besides, the crystals analyzed by SEM presented typical calcite morphology. The CGS showed that CV16 is a Bacillus subtilis with several genes involved in CaCO3 precipitation. Moreover, the preliminary addition of this strain in mortars demonstrates their cracks self-healing ability and increased compressive strength after 63 days curing, without urea or calcium source. The precipitated crystals were identified by XRD as calcite and vaterite. This way, the strain CV16 has sustainable application potential in cementitious materials due to CaCO3 precipitation.