Leonesiella tetratriches sp. nov. from the Cantabrian Mountains (León, Spain)—first species of Cantabrian Leptodirini found in mesovoid shallow substratum (MSS) (Coleoptera, Leiodidae, Cholevinae, Leptodirini)

The mesovoid shallow substratum (MSS) is a unique habitat that shelters and serves as a microrefuge for epigean, endogean and hypogean invertebrate species. Understanding the MSS community′s spatio-temporal structure and species diversity patterns in relation to the environmental parameters plays a crucial role in conservation. In this study we investigated: i) the diversity and community structure of oribatid mites from edaphic habitat, superficial MSS (i.e., the upper layer of MSS) and deep MSS (i.e., lower layer of MSS) in an alpine region of Southern Carpathians, Romania, and ii) the relationships between the oribatid mite communities and the environmental variables, such as temperature and humidity. The composition and the structure of oribatid communities differed along the three habitats indicating possible habitat specialization. The structure of the oribatid community was influenced by temperature and humidity. The rich and mixed oribatid communities in the MSS and the oribatid communities' response to surface and subsurface environmental variables suggest that the MSS may offer a micro-refuge for edaphic species when the conditions in the surface habitats become too harsh. Thus, we suggest that MSS should be prioritized for conservation because it may be the key component in maintaining biodiversity.

Temporal and spatial dynamics of arthropod groups in terrestrial subsurface habitats in central Portugal

Mountain slopes covered with stone debris have been of special interest for zoologists since the pioneer work of Juberthie et al. (1980) who defined and described the Milieu Souterrain Superficiel, most popularly referred to in English as the Mesovoid Shallow Substratum (MSS). Today this particular habitat is classified as one of the several types of MSS, namely the colluvial MSS. In a number of recent publications, the MSS is considered as one of the Superficial Subterranean Habitats (SSHs) within a broader concept of the subterranean domain. According to a widely accepted idea, the SSHs are different in their nature but are all characterized by the absence of light which is regarded as the main factor responsible for the occurrence of troglomorphic fauna in these habitats, along with epigean species that are able to live in such conditions. The present study focuses on two julid millipedes — Typhloiulus orpheus Vagalinski, Stoev & Enghoff, 2015 and a yet undescribed genus and species of the tribe Typhloiulini — occurring in the transitional layer of fine rubble between the soil stratum and the MSS in limestone taluses in the Western Rhodope Mtn. It was revealed that the spatial distributions of the two species in the studied sites were remarkably confined and follow the same pattern, which is suggested to reflect narrow microhabitat specialization. This assumption is further supported by certain traits in the morphology and biology of the two diplopods. It can be concluded that both T. orpheus and the new genus and species are essentially stenotopic endogean elements with strict requirements for an aphotic, mesophilous, limestone environment. Given the specific ecological conditions, which differ from both the overlying soil layer and the underlying colluvial MSS, together with the existence of certain narrowly adapted species, it is worth considering the recognition of the intermediate “microvoid” breakstone layer as a separate shallow subterranean habitat.

Hidden biodiversity in the Iberian Mesovoid Shallow Substratum (MSS): New and poorly known species of the millipede genus Archipolydesmus Attems, 1898 (Diplopoda, Polydesmidae)

A special type of pitfall trap for sampling the MSS is presented, explaining in detail its design and installation. This trap can be used repeatedly for a long time, with minimal disturbance of the habitat once the system is stabilized. It is made of a PVC pipe with abundant small holes in its lower half, with a jar inside at the bottom containing the bait and preservative liquid. The pipe is set vertically underground in such way that the holes reach the MSS, and the top remains a few centimetres below surface, closed with a cap and covered by soil. The use of this trap in the volcanic MSS on the Canary Islands (Spain) has shown surprising results.

Many species in the spider genus Cybaeodes Simon, 1878 have been described from caves and show marked adaptive characters to the underground environment, being considered troglobitic species. They have also recently been captured in the MSS (Mesovoid Shallow Substratum), a poorly known but species-rich habitat that lies between the superficial ground and the deep ground environment. Given the particular habitat of Cybaeodes and the difficulty of studying it, the diversity, biology and geographic distribution of this genus remain poorly known. The Prebaetic Mountain Range, in the Iberian Peninsula, appears to be a suitable region for this genus, from which three species are described from caves. In this work, we report on the taxonomic results of MSS samplings focused on the genus Cybaeodes in the region. Specimens were collected in alluvial and colluvial MSS using subterranean sampling devices. Samplings provided two new species for science, namely Cybaeodes bernia Ribera & Domènech sp. nov. and Cybaeodes gallinera Ribera & Domènech sp. nov. We also describe the male of Cybaeodes magnus Ribera & De Mas, 2015, previously unknown, and contribute new biogeographic data for Cybaeodes dosaguas Ribera & De Mas, 2015. This work increases our knowledge on the diversity and distribution of this still poorly known genus, and it highlights the importance of studying undersampled habitats such as the MSS.

Arthropod biodiversity patterns point to the Mesovoid Shallow Substratum (MSS) as a climate refugium

<>Earlier studies suggested that the Mesovoid Shallow Substratum (MSS), a subterranean network of voids immediately under the soil and scree horizon, might play an important role in the life cycle of some troglobitic species. No ecological studies have been conducted to test whether this terrestrial shallow subterranean habitat only plays an important role for a few subterranean or preferential species, or whether it is also important for the soil faunal structure and dynamics. We investigated the spatial and temporal patterns of the arthropod community in the MSS and sub-alpine scree and analysed the correlations with environmental variables. We identified 140 soil-dwelling, characteristic and troglobitic species that inhabited the MSS in different seasonal assemblages. Combined statistical analyses of the environmental factors and seasonal variation in arthropod abundance and biomass emphasized the importance of the MSS as an ecological microrefuge for many soil-dwelling species (including important predators and detritivores) which usually live in the adjacent forests or mountain pastures. Conservation plans for invertebrates should include the protection of the MSS.

Millipedes (Diplopoda), with a few notable exceptions, are poor dispersers, showing a very high degree of endemicity, not the least in mountains. The first samplings of the Mesovoid Shallow Substratum (MSS) of the higher altitudes of the Sierra Nevada Mountains (Baetic System, Southern Spain) have led to the discovery of a high number of millipedes, each of the species present showing a different degree of establishment in this subterranean environment. An update of the knowledge on the millipedes of this region, the first data of the millipede communities in the MSS and the description of Ceratosphys cryodeserti Gilgado, Mauriès & Enghoff n. sp. are here provided, as well as the first data on the humidity and temperature fluctuations in the MSS of this high mountain. The new species is similar to other Baetico-Riffan species, while the only previously known congener from the region, C. soutadei Mauriès, 1969, has more similarities to certain Pyrenean species. Biogeographical relationships of all the captured species are also discussed.

Summary The Iberian endemic genus Tinautius Mateu, 1997 (Carabidae: Pterostichinae: Pterostichini) is distributed in subterranean habitats of the Betic Systems (SE Spain). It is represented by two hypogean species with different grades of troglobiomorphism: Tinautius troglophilus Mateu, 1997 and T. exilis Mateu, 2001. New records are provided for the two species; in the case of T. exilis, it is for first time recorded from the mesovoid shallow substratum (MSS) of the Sierra de Gádor. Morphological and morphometric differences between species were thorough assessed and compared in collection material from type and new localities (caves and MSS). The results support the segregation of both species in different genera. The genus Gadorites n. gen. is proposed, in which Gadorites exilis (Mateu, 2001) n. comb. is placed. Characters of taxonomical relevance are described and illustrated in detail. Similarities and differences to Caucasian subterranean Pterostichini are discussed. Implications of the presence of G. exilis n. comb. in the MSS are exposed.

Simple SummaryThe interest in the fauna of the colluvial mesovoid shallow substratum (MSS) led us to install a series of pitfall traps (subterranean sampling devices or SSDs) for a full year in the Sierra de Guadarrama. This paper presents the comparative results between the captures at two different periods of the year and allows the description of a new species, found only in one of those periods. It seems proven that there are species present throughout the year, but others also predominate, or are exclusive, to just one of them. This study indicates, again, that the colluvial MSS has a particular species composition for the taxon Collembola, different from the surface, a perfectly differentiated habitat.An intensive sampling in a colluvial mesovoid shallow substratum (MSS) of the Sierra de Guadarrama National Park, using 33 subterranean sampling devices (SSDs) is the origin of the Collembola studied in this paper. The data were obtained from the second extraction of the traps, in operation between October of 2015 and May of 2016. This paper presents the faunistic and diversity data along with the entire park (mostly at sampling points above 200 m a.s.l.) for this period, compares the data between the first extraction of the traps and the second one, and describes one species of the genus Pseudosinella that appears as new in the second campaign.

Iron Formations (IF) are threatened by mining, particularly the Mesovoid Shallow Substratum (MSS), an understudied subterranean environment. We evaluate the spatiotemporal patterns of subterranean fauna in MSS of iron duricrust (canga)in the Iron Quadrangle and Southern Espinhaço Range, southeastern Brazil. Samplings took place between July 2014 and June 2022 using five trap types. We sampled 108,005 individuals, 1,054 morphospecies, and seven phyla, globally the largest dataset on MSS in IF. Arthropoda represented 97% of all invertebrates sampled. We identified 31 troglomorphic organisms, primarily Arthropoda and Platyhelminthes. MSS traps were the most efficient method, capturing 80% of all invertebrates. Morphospecies were more prevalent in each locality than shared among localities. Species replacement was the main processes to spatial differences. Over time, we found a decrease of total dissimilarity and importance of species replacement for troglomorphic organisms. A positive correlation between spatial distance and compositional dissimilarity of invertebrates was found. Iron Quadrangle and Southern Espinhaço Range showed marked differences in the spatiotemporal patterns of subterranean fauna. Brazilian IF are threatened, with their biological significance not fully understood but highly endangered due their limited distribution. Conservation efforts require a comprehensive understanding of both biotic and abiotic factors shaping the entire IF ecosystem.

In siliceous landscapes, study of the mesovoid shallow substratum (MSS) provides interesting species records. The Cholevinae Kirby, 1837 are normally found in the forest litter, and they also are a constant element in underground habitats. However, their knowledge is totally lacking in relation to the underground realm of Sierra de Guadarrama National Park (Spain). Over the period of a year, the MSS of this mountain range was prospected to acquire first insights into the Cholevinae species established in this habitat. The prior literature was reviewed to establish an initial checklist of the Cholevinae species in the National Park, and distributional maps of the captured species were provided for the area. Twelve species of Cholevinae were captured, five of which are new records for the National Park, four for the province of Segovia, and one for the province of Madrid. All the species present wide Iberian ranges, except Choleva (Choleva) cisteloides (Frölich, 1799), whose new record notably expands its known distribution range. Ten species had been identified in subterranean habitats before, six of which have been previously reported in the MSS. The species accumulation curve built for the observed species richness showed that the inventory was not complete. Finally, the collection of Choleva (Cholevopsis) punctata Brisout, 1866 facilitated detailed study of the taxonomic characters used for the identification of Choleva (C.) punctata and Choleva (C.) securiformis Blas, 1980, allowing us to propose the synonymisation of C. (C.) securiformis n. syn. into C. (C.) punctata. This study highlights the importance of investigating hidden habitats, such as the MSS in siliceous landscapes, so as to uncover the previously unknown biodiversity, even in protected natural areas supposedly well studied.

En este trabajo se documenta por primera vez el hallazgo de ejemplares de un crustáceo (Malacostraca, Bathynellacea) que vive exclusivamente en las aguas subterráneas de todo el mundo, en un hábitat inusual: el medio subterráneo superficial (MSS), un medio terrestre sin luz y saturado de humedad. Especímenes de la familia Parabathynellidae han sido encontrados en dispositivos de muestreo dispuestos para la recogida de fauna subterránea terrestre en el MSS del Parque Nacional de la Sierra de Guadarrama (Madrid, España). Se han identificado dos especies, de dos géneros diferentes, Hexabathynella nicoleiana Camacho, 1986 y Hexaiberobathynella mateusi (Galhano, 1967), mediante estudio morfológico. Las secuencias del gen 18S de varios ejemplares confirman su adscripción genérica. Estas especies eran ya conocidas en la provincia de Madrid.

Poduromorpha (Collembola) from a sampling in the mesovoid shallow substratum of the Sierra de Guadarrama National Park (Madrid and Segovia, Spain): Taxonomy and Biogeography