Alien land snail species are increasing exponentially

A new study compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean.

Invasive land snail species can displace native species and harm human health. A recent study by the Leibniz Institute for Biodiversity Change Analysis (LIB) compiles an overview of the exponential increase and dynamic spread of land snail species introduced to Europe and the Mediterranean from other continents.

Laevicaulis alte, an invasive species from tropical Africa that was introduced into Egypt in 2018. © Reham F. Ali

To date, there is a lack of information for the spread of alien species, especially invertebrates such as snails. “Despite efforts to compile lists of alien species, there is not even a well-documented inventory of alien invertebrate species for Europe,” emphasizes Prof. Dr. Bernhard Hausdorf, section leader Mollusca at LIB. His study, just published in the journal NeoBiota, provides a basis for decisions on further measures to control or eradicate introduced populations.

Alien land snail species in the Western Palaearctic Region: Zonitoides arboreus, Hawaiia minuscula, Guppya gundlachii, Polygyra cereolus

Land snails play a supporting role in ecosystems. They decompose decaying plants and thus play an important role in nutrient cycling and soil formation. However, more and more species are being spread beyond their native range, usually by humans, sometimes intentionally, but often unintentionally by goods or travellers.

The study examines 22 land snail species introduced to Europe and the Mediterranean from other continents. Most of them are small, live on decaying plant parts and apparently cause few problems. In contrast, carnivorous species can threaten native species; and species that feed on living plants can cause damage to agriculture. Some even serve as hosts and vectors of parasites that can cause brain encephalitis, for example, and thus can indirectly harm human health.

Alien land snail species in the Western Palaearctic Region: Paralaoma servilis and Helicodiscus parallelus.

Harmful species include the Laevicaulis species recently introduced to the Mediterranean from tropical Africa and the African giant snail Lissachatina fulica. They can cause economic damage on irrigated farmland or in greenhouses by destroying or contaminating crops, making them unsaleable.

Hausdorf’s study compiles records of land snail species introduced to the Western Palearctic region, Europe and the Mediterranean, from other regions after 1492 and established in the wild. In doing so, he observes that the number of alien species has increased steadily since the 19th century, even exponentially from the 1970s onward, and that the introduced species have become more widespread.

Within Europe, alien species generally spread from south to north and from west to east. Thirteen of the 22 species studied were from North America, three from sub-Saharan Africa, two from the Australian region, three probably from the Oriental region, and one from South America.

Alien land snail species in the Western Palaearctic Region: llopeas clavulinum, Allopeas gracile, Lissachatina fulica, Paropeas achatinaceum, and Discocharopa aperta.

Even if trade relations and the spread of species can be correlated, Hausdorf believes that the prevailing climate is primarily decisive: “The spread of many of the introduced species, especially the tropical species dispersing in Mediterranean, is probably favored by climate change.”

Bernhard Hausdorf, “Distribution patterns of established alien land snail species in the Western Palaearctic Region”, NeoBiota, Pensoft
https://doi.org/10.3897/neobiota.81.96360

Press release originally published by Leibniz Institute for the Analysis of Biodiversity Change. Republished with permission.

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Festschrift for Dr Jason Londt at African Invertebrates invites submissions

African Invertebrates invites any submissions linked to Jason, new species descriptions, revisions of taxa he has worked on, or any work based on specimens he collected.

From 1976 to 1994, Jason Londt was Assistant Director at the Natal Museum (now KwaZulu-Natal Museum) in South Africa, publisher of the African Invertebrates journal. Then, he became Director before retiring in 2003.

During his career at the Museum and well after that, Jason described more than 570 species and 46 genera of insects from the Afrotropics. While the majority of his work was on the robber fly family (Asilidae), Jason also worked on hangingflies (Bittacidae) and ticks. He was also a prolific collector of many other insects, still kept in the collection of the KwaZulu-Natal Museum. 

Dr Jason Gilbert Hayden Londt

Jason’s fieldwork was extensively targeting the diverse habitats in South Africa: from the subtropical coast of KwaZulu-Natal, the grasslands in the Midlands around Pietermaritzburg – where the museum is based – and further north in the Highveld, to the higher elevations of the Drakensberg Mountains bordering Lesotho, and from the Succulent and Nama Karoo, to the diverse Fynbos habitats along the south-western coast of South Africa. Additional major fieldwork took place in Namibia, Kenya, Malawi, and to a lesser extent: Eswatini (Swaziland) and Cote d’Ivoire. In addition to utilising the collected material for taxonomic work, Jason also used his field trips to publish behavioural observations and prey selection of Asilidae species.

To celebrate Jason’s career achievements and his 80th birthday, African Invertebrates will be publishing a Festschrift in his honour in April 2023. We invite any submissions linked to Jason, new species descriptions, revisions of taxa he has worked on, or any work based on specimens collected by Jason.

This issue will be edited by Dr Torsten Dikow (Smithsonian National Museum of Natural History, USA), Dr Kirstin Williams (KwaZulu-Natal Museum) and Dr John Midgley (KwaZulu-Natal Museum). 

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Submission deadline: 31 December 2022

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Find more about the upcoming Festschrift on the African Invertebrates’ journal website. 

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Journal Alpine Entomology calls for contributions in a new topical collection

“Trends in Arthropods of Alpine Aquatic Ecosystems” is the first topical collection for the journal of the Swiss Entomological Society

“Trends in Arthropods of Alpine Aquatic Ecosystems” is the first topical collection for the journal of the Swiss Entomological Society

The open-access, peer-reviewed scholarly journal Alpine Entomology, published by Pensoft on behalf of the Swiss Entomological Society, announced its very first topical collection of articles, which will be focusing on arthropods associated with aquatic ecosystems in mountainous regions.

The journal is currently inviting scientists, working on aquatic fauna from alpine habitats, to openly publish their research articles and short notices that provide evidence how arthropods’ biogeography, species communities, distribution, behaviour and morphology have changed in recent times. 

“Aquatic invertebrates are key indicators of global or local changes. Furthermore, many aquatic ecosystems are closely linked to mountains because they originate in them. Many valuable unpublished datasets on aquatic arthropod fauna may therefore be available from mountainous regions,”

explain the rationale behind the newly opened topical article collection guest editors Dr. Jean-Luc Gattolliat (Museum of Zoology, Lausanne and University of Lausanne, Switzerland) and Dr. David Muranyi (Eszterházy Károly Catholic University, Hungary).

The aim of the “Trends in Arthropods of Alpine Aquatic Ecosystems” collection is to bring together data and findings about what many agree is the most impacted type of environment on Earth: aquatic ecosystems, especially running waters.

The collection will remain open for submissions for the next two years. In the meantime, the accepted manuscripts will be published on a rolling basis, as soon as they are ready for publication.

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Visit the journal’s website at: https://alpineentomology.pensoft.net/ 
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48 years of Australian collecting trips in one data package

From 1973 to 2020, Australian zoologist Dr Robert Mesibov kept careful records of the “where” and “when” of his plant and invertebrate collecting trips. Now, he has made those valuable biodiversity data freely and easily accessible via the Zenodo open-data repository, so that future researchers can rely on this “authority file” when using museum specimens collected from those events in their own studies. The new dataset is described in the open-access, peer-reviewed Biodiversity Data Journal.

While checking museum records, Dr Robert Mesibov found there were occasional errors in the dates and places for specimens he had collected many years before. He was not surprised.

“It’s easy to make mistakes when entering data on a computer from paper specimen labels”, said Mesibov. “I also found specimen records that said I was the collector, but I know I wasn’t!”

One solution to this problem was what librarians and others have long called an “authority file”.

“It’s an authoritative reference, in this case with the correct details of where I collected and when”, he explained.

“I kept records of almost all my collecting trips from 1973 until I retired from field work in 2020. The earliest records were on paper, but I began storing the key details in digital form in the 1990s.”

The 48-year record has now been made publicly available via the Zenodo open-data repository after conversion to the Darwin Core data format, which is widely used for sharing biodiversity information. With this “authority file”, described in detail in the open-access, peer-reviewed Biodiversity Data Journal, future researchers will be able to rely on sound, interoperable and easy to access data, when using those museum specimens in their own studies, instead of repeating and further spreading unintentional errors.

“There are 3829 collecting events in the authority file”, said Mesibov, “from six Australian states and territories. For each collecting event there are geospatial and date details, plus notes on the collection.”

Mesibov hopes the authority file will be used by museums to correct errors in their catalogues.

“It should also save museums a fair bit of work in future”, he explained. “No need to transcribe details on specimen labels into digital form in a database, because the details are already in digital form in the authority file.”

Mesibov points out that in the 19th and 20th centuries, lists of collecting events were often included in the reports of major scientific expeditions.

“Those lists were authority files, but in the pre-digital days it was probably just as easy to copy collection data from specimen labels.”

“In the 21st century there’s a big push to digitise museum specimen collections”, he said. “Museum databases often have lookup tables with scientific names and the names of collectors. These lookup tables save data entry time and help to avoid errors in digitising.”

“Authority files for collecting events are the next logical step,” said Mesibov. “They can be used as lookup tables for all the important details of individual collections: where, when, by whom and how.”

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Research paper:

Mesibov RE (2021) An Australian collector’s authority file, 1973–2020. Biodiversity Data Journal 9: e70463. https://doi.org/10.3897/BDJ.9.e70463

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Robert Mesibov’s webpage: https://www.datafix.com.au/mesibov.html

Robert Mesibov’s ORCID page: https://orcid.org/0000-0003-3466-5038

Dwarfs under dinosaur legs: 99-million-year-old millipede discovered in Burmese amber

A 3D reconstruction of the fossil allowed for the description of an entirely new suborder


The newly described millipede (Burmanopetalum inexpectatum) rendered using 3D X-ray microscopy. Image by Leif Moritz.

Even though we are led to believe that during the Cretaceous the Earth used to be an exclusive home for fearsome giants, including carnivorous velociraptors and arthropods larger than a modern adult human, it turns out that there was still room for harmless minute invertebrates measuring only several millimetres.

Such is the case of a tiny millipede of only 8.2 mm in length, recently found in 99-million-year-old amber in Myanmar. Using the latest research technologies, the scientists concluded that not only were they handling the first fossil millipede of the order (Callipodida) and also the smallest amongst its contemporary relatives, but that its morphology was so unusual that it drastically deviated from its contemporary relatives.

As a result, Prof. Pavel Stoev of the National Museum of Natural History (Bulgaria) together with his colleagues Dr. Thomas Wesener and Leif Moritz of the Zoological Research Museum Alexander Koenig (Germany) had to revise the current millipede classification and introduce a new suborder. To put it in perspective, there have only been a handful of millipede suborders erected in the last 50 years. The findings are published in the open-access journal ZooKeys.

To analyse the species and confirm its novelty, the scientists used 3D X-ray microscopy to ‘slice’ through the Cretaceous specimen and look into tiny details of its anatomy, which would normally not be preserved in fossils. The identification of the millipede also presents the first clue about the age of the order Callipodida, suggesting that this millipede group evolved at least some 100 million years ago. A 3D model of the animal is also available in the research article.

Curiously, the studied arthropod was far from the only one discovered in this particular amber deposit. On the contrary, it was found amongst as many as 529 millipede specimens, yet it was the sole representative of its order. This is why the scientists named it Burmanopetalum inexpectatum, where “inexpectatum” means “unexpected” in Latin, while the generic epithet (Burmanopetalum) refers to the country of discovery (Myanmar, formerly Burma).

Lead author Prof. Pavel Stoev says:

We were so lucky to find this specimen so well preserved in amber! With the next-generation micro-computer tomography (micro-CT) and the associated image rendering and processing software, we are now able to reconstruct the whole animal and observe the tiniest morphological traits which are rarely preserved in fossils. This makes us confident that we have successfully compared its morphology with those of the extant millipedes. It came as a great surprise to us that this animal cannot be placed in the current millipede classification. Even though their general appearance have remained unchanged in the last 100 million years, as our planet underwent dramatic changes several times in this period, some morphological traits in Callipodida lineage have evolved significantly.


The newly described millipede seen in amber. Image by Leif Moritz.

Co-author Dr. Thomas Wesener adds:

“We are grateful to Patrick Müller, who let us study his private collection of animals found in Burmese amber and dated from the Age of Dinosaurs. His is the largest European and the third largest in the world collection of the kind. We had the opportunity to examine over 400 amber stones that contain millipedes. Many of them are now deposited at the Museum Koenig in Bonn, so that scientists from all over the world can study them. Additionally, in our paper, we provide a high-resolution computer-tomography images of the newly described millipede. They are made public through MorphBank, which means anyone can now freely access and re-use our data without even leaving the desk.”

Leading expert in the study of fossil arthropods Dr. Greg Edgecombe (Natural History Museum, London) comments:

“The entire Mesozoic Era – a span of 185 million years – has until now only been sampled for a dozen species of millipedes, but new findings from Burmese amber are rapidly changing the picture. In the past few years, nearly all of the 16 living orders of millipedes have been identified in this 99-million-year-old amber. The beautiful anatomical data presented by Stoev et al. show that Callipodida now join the club.”

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Original source:

Stoev P, Moritz L, Wesener T (2019) Dwarfs under dinosaur legs: a new millipede of the order Callipodida (Diplopoda) from Cretaceous amber of Burma. ZooKeys 841: 79-96. https://doi.org/10.3897/zookeys.841.34991

Conservation and nameless earthworms: Assessors in the dark?

Species that live exclusively in a single region are at a particular risk of extinction. However, for them to be protected, thorough assessments of the environmental impacts need to be performed.

There are more than 100 earthworm species living in the soil and dead wood of KwaZulu-Natal Province, South Africa. Most of them live exclusively in small regions in the province, which makes them extremely vulnerable.

To scientists Dr Adrian J. Armstrong, Ezemvelo KZN Wildlife, and Ms Thembeka Nxele, KwaZulu-Natal Museum, the problem is twofold. Firstly, they note that the expression “out of sight, out of mind” is very suitable for the case of the endemic earthworms in South Africa. Secondly, they point out that the lack of common names for these species is a stumbling block that hinders their inclusion in conservation assessments.

As a result, the researchers try to rectify this situation by assigning standardised English names to the endemic earthworms in KwaZulu-Natal. Their article is published in the open access journal African Invertebrates.

Scientific names are often intractable to non-specialists, and the lack of common names leaves environmental assessors in the dark when they need to figure out which earthworms may occur at a development site. In the meantime, it has been found that about 50% of the native vegetation in KwaZulu-Natal has already been removed as a result of infrastructure construction and the figure is rising.

“The indigenous earthworms generally don’t survive in developed areas,” say the authors.

For instance, the informal use of an English name (green giant wrinkled earthworm) for the species Microchaetus papillatus, has facilitated the inclusion of this species in environmental impact assessments in KwaZulu-Natal.

While the green giant wrinkled earthworm does occur in a relatively large and rapidly developing area in KwaZulu-Natal, other species live in smaller areas that have been urbanised even more.

The extinction of these earthworms is not only undesirable from the point of view of biodiversity advocates – the role of this group of soil organisms is impossible to replace fully with non-native earthworms. For example, some of the large indigenous earthworms (more than 1 m in length) burrow much deeper than the non-native species, thereby enriching and aerating the soil at greater depth.

The authors are hopeful that by giving the indigenous earthworms in KwaZulu-Natal common names, the threatened and endemic species will be conserved through inclusion in environmental impact assessments. Furthermore, they believe that earthworms could draw attention to the areas where they occur whenever a choice for new protected areas is to be made.

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Original source:

Armstrong AJ, Nxele TC (2017) English names of the megadrile earthworms (Oligochaeta) of KwaZulu-Natal. African Invertebrates 58(2): 11-20. https://doi.org/10.3897/AfrInvertebr.58.13226

Hidden diversity: 3 new species of land flatworms from the Brazilian Araucaria forest

A huge invertebrate diversity is hidden on the forest floor in areas of the Araucaria moist forest, Brazil. Land flatworms constitute a numerous group among these invertebrates occurring in the Neotropical region. Flatworms are considered to be top predators within the soil ecosystem, preying on other invertebrates.

fig_1_c_aureomaculataThe Araucaria moist forest is part of the Brazilian Atlantic Rain Forest and is considered a hotspot of land flatworm diversity, harboring many yet undescribed species. Study recently published in the open access journal ZooKeys describes three new species from areas covered by Araucaria moist forest in South Brazil, which belong to the Neotropical genus Cratera.

Land flatworms lack a water retention mechanism and have a low tolerance to intense changes in temperature and humidity. Their low vagility leads to the existence of a high number of endemic species. Thus, they are considered good bioindicators of the degree of impact on their habitat.

The new species are named after characteristics of their color pattern and are probably endemic for the study areas. Besides differing from each other, as well as from other species of the genus, by their characteristic color pattern, they also show other distinguishing features in the reproductive system. The study provides an identification key to the species of the genus.

The work was conducted by the south Brazilian research group on triclads, led by Dr. Ana Leal-Zanchet, of the Universidade do Vale do Rio dos Sinos (UNISINOS), in southern Brazil. The study was supported by the Brazilian Research Council (CNPq).fig_2_c_nigrimarginata

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Original source:

Rossi, I, Leal-Zanchet, A. (2017) Three new species of Cratera Carbayo et al., 2013 from Araucaria forests with a key to species of the genus (Platyhelminthes, Continenticola). ZooKeys 643 (2017): 1-32. doi: 10.3897/zookeys.643.11093

Unfamiliar bloodline: New family for an earthworm genus with exclusive circulatory system

New earthworm family, named Kazimierzidae, has been established for a South African indigenous genus of 21 species. Although the circulatory system in the group has been regarded as exclusive upon their original description in 2006, their raising to a family status have only recently been confirmed by a research team from South Africa.

Scientists Mrs Thembeka Nxele, Dr Danuta Plisko (original discoverer of the genus Kazimierzus, now known as family Kazimierzidae), affiliated with Natal Museum (NMSA), Oliver Tendayi Zishiri, affiliated with University of KwaZulu-Natal, and Dr Taro Mwabvu, University of Mpumalanga, looked into the earthworm collection at the NMSA, as well as the type material and the available literature. Their study is published in the open access journal African Invertebrates.

When compared to the rest of the members in the family Microchaetidae, where the former genus had been placed, the studied earthworms show a number of distinct characters, including an “exclusive” circulatory system. In these species it is a simple single tube stretching along the whole body.

All 21 earthworm species, now members of the newly established family, can only be found in small areas restricted in the western and south-western Atlantic coast of South Africa. These locations have long been known for their endemic invertebrates and diverse flora.

In their paper, the authors note that it is actually the restricted range, and therefore the specific ecological requirements, that might have led these earthworms to become that different from other species. Their distribution and, hence, poor dispersal ability, are also the reason why the newly established group would be particularly vulnerable if the habitat is transformed.

“The species distribution of earthworms in Southern Africa is presently poorly known hence the urgency for extended study on earthworm diversity and their distribution patterns,” point out the scientists. “Extensive earthworm collection in the western Atlantic coast may bring more data on this and other taxa.”

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Original source:

Nxele TC, Plisko JD, Mwabvu T, Zishiri TO (2016) A new family Kazimierzidae for the genus Kazimierzus, earlier recorded to the composite Microchaetidae (Annelida, Oligochaeta). African Invertebrates 57(2): 111-117. doi: 10.3897/AfrInvertebr.57.10042

Flightless survivors: Incredible invertebrate diversity in Los Angeles metropolitan area

Urban wildlife is surprisingly understudied. We tend to know more about animals in exotic places than about those that live in our cities.

This is why researchers Emile Fiesler, president of Bioveyda Biological Inventories, Surveys, and Biodiversity Assessments, USA, and Tracy Drake, manager of the Madrona Marsh Preserve, looked into the fauna of the Madrona Marsh Preserve, California, a small nature preserve in one of the world’s largest metropolitan areas.

Consequently, they published the astonishing number of 689 species of invertebrates, which have managed to survive decades of farming and oil exploration, followed by development pressures, in the open access Biodiversity Data Journal. The study was minimally invasive as the live animals have been recorded with macro-photography.

Even though it is the insects that first developed the ability to fly, long before the dinosaurs became birds, the latter have always received the most of our attention. This major evolutionary breakthrough, which has occurred more than once in the past, is also a reason why insects are currently the most diverse animals on earth in terms of number of species.

“Insects and other invertebrates have filled all ecological niches and all corners of our planet,” explain the authors. “No surprise that these small creatures conquered our cities and invaded our homes as well.”

Most of the urban dwellers, however, have been introduced – accidentally or deliberately – by humans.

“The remainder – native ‘wild’ species – are able to survive in the city mainly due to their adaptivity,” they point out. “It is therefore surprising to find a number of flightless species in a small area surrounded by urbanization.”

The Madrona Marsh Preserve is located in Torrance, which is part of the Los Angeles metropolitan area. The greater Los Angeles Metropolitan area is one of the world’s largest, with a human population of more than 17 million.

Figure 2 = Bradynobaenid Wasp Fiesler-2016The Madrona Marsh Preserve, boasting seasonal wetlands, is well known as a birdwatchers’ paradise. Besides birds, its other vertebrates (mammals, reptiles, amphibians, and fishes), as well as its flowering plants, are relatively well known. The invertebrate fauna of the Preserve, on the other hand, aside from butterflies and dragonflies, was virtually unknown.

Interestingly, night surveys revealed the presence of a ‘second shift’ diversity, or creatures seemingly complementary to those active during the day.

Among the long-time survivors are wingless camel crickets as well as velvet ants, which are wasps whose flightless females look like furry ants. Another curiosity that intrigued the researchers is an obscure flightless female bradynobaenid wasp.

The researchers were especially surprised by their encounter with a large Solifugid [image 3] – also known as Camel Spider or Wind Scorpion. Solifugids are little-known arachnids that are neither spiders, nor scorpions, and can grow up to 15 cm (6 in). Their order’s name Solifugae translates from Latin as “those that flee from the sun”.Figure 3 = Solifugid Fiesler-2016

All in all, the biodiversity study resulted in 689 species without a backbone, belonging to 13 classes, 39 orders, and 222 families, found on this island surrounded by urbanization.

“Not unlike the moas and dodos, these ‘island’ inhabitants stayed grounded through the ages,” acknowledge the researchers.

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Original source:

Fiesler E, Drake T (2016) Macro-invertebrate Biodiversity of a Coastal Prairie with Vernal Pool Habitat. Biodiversity Data Journal 4: e6732. doi: 10.3897/BDJ.4.e6732

 

About the authors:

Emile Fiesler is president of Bioveyda Biodiversity Inventories, Surveys, and Studies, and Tracy Drake is manager of the Madrona Marsh Preserve.

Underground gourmet: Selected terrestrial cave invertebrates and their meal preferences

Doubting whether terrestrial cave invertebrates feed on just anything they can find in the harsh food-wise environment underground, Dr. Jaroslav Smrz, fromCharles University, Vinicna, and his international team conducted a research in Slovakian and Romania caves. They tested the hypothesis that these species have rather negligible selection of food. Their microanatomical research into the gut content of several microwhip scorpions, oribatid mites, millipedes, springtails and crustaceans showed, however, that there is an evident meal preference among the species.

The results confirmed that the studied groups can adapt and develop under the pressure of extreme environmental factors. Therefore, the researchers concluded a low level of food competition. The study is available in the Subterranean Biology open-access journal.

The scientists studied the cells and tissues of the selected invertebrates and found out that the gut contents were nearly identical between the representatives of each group. This was the case even when the specimens had been collected from various locations. For instance, all microwhip scorpions proved a preference for cyanobacteria, while the mites favored the bacteria found in bat guano and the millipedes – fungi.

“The limited food offer seems to be used very unambiguously and thoroughly by the invertebrate communities,” the research team explained. “Therefore, the competition for food can be actually regarded as very low,” they concluded.

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Original source:

Smrz J, Kovac L, Mikes J, Sustr V, Lukesova A, Tajovsky K, Novakova A, Reznakova P (2015) Food sources of selected terrestrial cave arthropods. Subterranean Biology 16: 37-46. doi:10.3897/subtbiol.16.8609