eDNA in subterranean ecosystems: Applications, technical aspects, and future prospects.

Monitoring of biota is pivotal for the assessment and conservation of ecosystems. Environments worldwide are being continuously and increasingly exposed to multiple adverse impacts, and the accuracy and reliability of the biomonitoring tools that can be employed shape not only the present, but more importantly, the future of entire habitats. The analysis of environmental DNA (eDNA) metabarcoding data provides a quick, affordable, and reliable molecular approach for biodiversity assessments. However, while extensively employed in aquatic and terrestrial surface environments, eDNA-based studies targeting subterranean ecosystems are still uncommon due to the lack of accessibility and the cryptic nature of these environments and their species. Recent advances in genetic and genomic analyses have established a promising framework for shedding new light on subterranean biodiversity and ecology. To address current knowledge and the future use of eDNA methods in groundwaters and caves, this review explores conceptual and technical aspects of the application and its potential in subterranean systems. We briefly introduce subterranean biota and describe the most used traditional sampling techniques. Next, eDNA characteristics, application, and limitations in the subsurface environment are outlined. Last, we provide suggestions on how to overcome caveats and delineate some of the research avenues that will likely shape this field in the near future. We advocate that eDNA analyses, when carefully conducted and ideally combined with conventional sampling techniques, will substantially increase understanding and enable crucial expansion of subterranean community characterisation. Given the importance of groundwater and cave ecosystems for nature and humans, eDNA can bring to the surface essential insights, such as study of ecosystem assemblages and rare species detection, which are critical for the preservation of life below, as well as above, the ground.

Ecotoxicological effects of anthropogenic stressors in subterranean organisms: A review.

How anthropogenic stressors affect biodiversity is a central question in a changing world. Subterranean ecosystems and their biodiversity are particularly vulnerable to change, yet, these species are frequently neglected in analyses of global biodiversity and assessments of ecological status and risk. Are these hidden species affected by anthropogenic stressors? Do they survive outside of the current thermal limits of their ecosystems? These and other important questions can be addressed with ecotoxicological testing, relating contaminants and temperature resistance of species with measured environmental concentrations and climatic data. Ecotoxicological knowledge specific to subterranean ecosystems is crucial for establishing thresholds for their protection, but such data are both scarce and scattered. Here, we review the existing ecotoxicological studies of these impacts to subterranean-adapted species. An effort that includes 167 measured endpoints and presents a database containing experimentally derived species' tolerance data for 28 contaminants and temperature, for 46 terrestrial and groundwater species, including fungi and animals. The lack of standard data among the studies is currently the major impediment to evaluate how stressors affect subterranean-adapted species and how differently they respond from their relatives at surface. Improving understanding of ecotoxicological effects on subterranean-adapted species will require extensive analysis of physiological responses to a wide range of untested stressors, standardization of testing protocols and evaluation of exposures under realistic scenarios.

Review of Eyeless Pseudosinella Schäffer (Collembola, Entomobryidae, and Lepidocyrtinae) from Brazilian Caves.

Herein, eyeless Pseudosinella species from Brazilian caves are reviewed, including the description of 23 new species, new records plus additional notes on the descriptions of P. ambigua Zeppelini, Brito, and Lima and of P. guanhaensis Zeppelini, Brito, and Lima. We also provide an identification key to 27 eyeless species recorded from Brazil. To organize the 26 Brazilian eyeless taxa analyzed in this work, we organize them in apparently artificial groups: 11 species have one larger tooth on the unguiculus outer lamella (petterseni group); one presents unguiculus outer lamella smooth or serrated (never with a larger tooth), with 9 held prelabral chaetae undivided and the last 6 held prelabral chaetae bifurcated. The Brazilian species of eyeless Pseudosinella herein described present a remarkably conservate dorsal chaetotaxy; therefore, the main diagnostic characters are related to other features like prelabral, labral, and ventral head chaetotaxy and empodial complex morphology. In addition, our study suggests that Brazilian caves possibly shelter a great diversity of Pseudosinella taxa, several of them potentially cave dependent.

Shedding light on the hidden world of subterranean fauna: A transdisciplinary research approach.

Subterranean environments contain a diverse and unique obligate fauna: either aquatic living in the groundwater or terrestrial living in voids above the water table. In the arid region of the western part of the Australian continent, a particularly rich subterranean fauna coincides with a concentration of natural resource extraction operations. Since the inclusion of subterranean fauna in assessments of environmental impact in the mid-1990s, taxonomic research in Australia on this group of mainly invertebrates has grown exponentially. However, remaining knowledge gaps continue to frustrate both environmental regulators and development proponents due to high uncertainty in the decision-making process. In early 2017, the Western Australian Biodiversity Science Institute was tasked with leading the development of a research program to improve on the current state of knowledge of subterranean fauna. To balance the diverse environmental, economic and social needs of a range of stakeholders, transdisciplinary principles were applied to program development. A clear consensus on five broad focus areas to progress include: (1) data consolidation; (2) resilience to disturbance; (3) survey and sampling protocols; (4) abiotic and biotic habitat requirements; and (5) species delineation. In the context of these focus areas; we describe the research program development, reviewing the status of knowledge within each focus area, and the research initiatives to close the gaps in knowledge. We argue that, by adopting a transdisciplinary approach, the likelihood of success of the research program, as measured by the effective translation and adoption of research findings, will be maximized. This review is timely given the ever-increasing demand on groundwater systems for water extraction worldwide. A holistic understanding of the influence of anthropogenic activities on these ecosystems, and the functional role of organisms within them, will help to ensure that their health is not compromised.

Speciation in fractured rock landforms: towards understanding the diversity of subterranean cockroaches (Dictyoptera: Nocticolidae: Nocticola) in Western Australia.

Three new species of subterranean cockroach of the genus Nocticola from the Pilbara region of Western Australia are described on morphological characters of males. Nocticola quartermainei n. sp., Nocticola cockingi n. sp. and Nocticola currani n. sp. occur in fractured rock landforms and have varying degrees of troglomorphies. Sequence divergence of mitochondrial cytochrome c oxidase subunit I (COXI) clearly demonstrated populations are reproductively isolated over very short distances for the highly troglomorphic Nocticola cockingi n. sp. and Nocticola currani n. sp. and conversely, there is less isolation within the same landforms for the less troglomorphic Nocticola quartermainei n. sp.

Terrestrial Gastropoda from the caves of Presidente Olegário, southeastern Brazil / Gastrópodes terrestres de cavernas da região de Presidente Olegário no sudeste brasileiro

Abstract: Samples of terrestrial gastropods were collected year-round in seven caves in Presidente Olegário municipality, Minas Gerais state, southeastern Brazil, during several expeditions from 2012 to 2014. Twenty-four taxa (plus a single freshwater species), mainly stylommatophorans, were found in the material. The following species are reported for the first time for Minas Gerais state: Alcadia iheringi Wagner, 1910 and Helicina sordida King, 1831 (Helicinidae); Cecilioides consobrina (d'Orbigny, 1841) (Ferussaciidae); Entodina gionensis Morretes, 1940 and Scolodonta interrupta (Suter, 1900) (Scolodontidae); Megalobulimus sanctipauli (Ihering & Pilsbry, 1900) (Strophocheilidae); Drymaeus coarctatus (Pfeiffer, 1845) (Bulimulidae); Habroconus semenlini (Moricand, 1846) (Euconulidae); and Solaropsis aff. rosaria (Pfeiffer, 1849) (Solaropsidae). Furthermore, the species Drymaeus iracema (Simone, 2015) and Drymaeus terreus (Simone, 2015) are synonymized with Drymaeus coarctatus (L. Pfeiffer, 1845).

Resumo: Amostras de gastrópodes terrestres foram coletadas em sete cavernas na região do município de Presidente Olegário, Minas Gerais, Brasil, durane múltiplas expedições ao longo dos anos de 2012 a 2014. Vinte-e-quatro táxons (mais uma única espécie dulciaquícola) foram encontrados, em sua maioria Stylommatophora. As seguintes espécies são aqui reportadas pela primeira vez para o estado de Minas Gerais: Alcadia iheringi Wagner, 1910 e Helicina sordida King, 1831 (Helicinidae); Cecilioides consobrina (d'Orbigny, 1841) (Ferussaciidae); Entodina gionensis Morretes, 1940 e Scolodonta interrupta (Suter, 1900) (Scolodontidae); Megalobulimus sanctipauli (Ihering & Pilsbry, 1900) (Strophocheilidae); Drymaeus coarctatus (Pfeiffer, 1845) (Bulimulidae); Habroconus semenlini (Moricand, 1846) (Euconulidae); e Solaropsis aff. rosaria (Pfeiffer, 1849) (Solaropsidae). Além disso, as espécies Drymaeus iracema (Simone, 2015) e Drymaeus terreus (Simone, 2015) são aqui sinonimizadas com Drymaeus coarctatus (L. Pfeiffer, 1845).