Pensoft blog - Part 53

Citizen scientists help expose presence of invasive Asian bamboo longhorn beetle in Europe

A worryingly high number of Asian bamboo longhorn beetles turn out to have been emerging across Europe for about a century already, finds an international research team. Curiously, the records of the invasive, non-native to the Old Continent species are mostly sourced from citizen scientists and online platforms, which proves the power of involving the public in species monitoring. The study is published in the open-access, peer-reviewed scientific journal BioRisk.

A worryingly high number of Asian bamboo longhorn beetles (Chlorophorus annularis) turn out to have been emerging across Europe for about a century already, finds an international research team, headed by researchers from the Center of Natural History, University of Hamburg, Germany. Curiously, the recent records of the invasive, non-native to the Old Continent species are mostly sourced from citizen scientists and online platforms, which proves the power of involving the public in species monitoring. The study is published in the open-access, peer-reviewed scientific journal BioRisk.

In our globalised world, which has already become victim to climate change and biodiversity loss, non-native species present a further threat to our ecosystems. Thus, the rising accounts of newly recorded alien species are of serious concern to both scientists and (inter)national institutions. However, surveying non-native species remains limited to a small fraction of species: those known to be particularly invasive and harmful.

One of the multitude of non-native species that are currently lacking efficient and coordinated surveying efforts is the Asian bamboo longhorn beetle (Chlorophorus annularis). Naturally occurring in temperate and tropical Southeast Asia, the insect feeds on a variety of plants, but prefers bamboo. Thus, due to the international trade of bamboo and the insects ‘travelling’ with the wood, the species has continuously been expanding its distribution around the world. Its first appearance in Europe was recorded back in 1924, when it was identified in England.

Bamboo longhorn beetle captured in Braintree, United Kingdom
**Photo by** Stephen Rolls

Back to our days, during a fieldwork practice for students at the University of Hamburg, held within the city because of the COVID-19 travelling restrictions, the team stumbled across a longhorn beetle, later identified by scientists as the Asian bamboo borer. Furthermore, it became clear that there were even more recent records published across different citizen science platforms, such as iNaturalist, iRecord and Waarneming.nl. Having taken the contacts of the citizen scientists from there, the researchers approached them to ask for additional collection details and images, which were readily provided. As a result, the researchers formally confirmed the presence of the Asian bamboo borer in Belgium and the Netherlands. In total, they reported thirteen new introductions of the species in Europe, which translates to a 42% increase of the records of the species for the continent.

“In light of the warming climate and a growing abundance of ornamental bamboo plants in Europe, the beetle might get permanently established. Not only could it become a garden pest, but it could also incur significant costs to the bamboo-processing industry,”
comments Dr Matthias Seidel, lead author of the study.

Having realised the potential of citizen science for bridging the gaps in invasive species monitoring, the researchers now propose for specialised platforms to be established with the aim to familiarise non-professional scientists with non-native species of interest and provide them with more sophisticated reporting tools. The aim is to speed up the identification of important alien species by collating records of specific species of interest, which are flagged and regularly exported from other citizen science databases and platforms.

Bamboo longhorn beetle captured in Lincoln, United Kingdom
**Photo by** Sheena Cotter

Original source:

Seidel M, Lüttke M, Cocquempot C, Potts K, Heeney WJ, Husemann M (2021) Citizen scientists significantly improve our knowledge on the non-native longhorn beetle Chlorophorus annularis (Fabricius, 1787) (Coleoptera, Cerambycidae) in Europe. BioRisk 16: 1–13. https://doi.org/10.3897/biorisk.16.61099

Two species and a single name: ‘Double identity’ revealed in a venomous banana spider

Phoneutria boliviensis in the Peruvian Amazon
Photo by N. Hazzi

Spiders from the genus Phoneutria – also known as banana spiders – are considered aggressive and among the most venomous spiders in the world, with venom that has a neurotoxic action. These large nocturnal spiders usually inhabit environments disturbed by humans and are often found in banana plantations in the Neotropical region.

One of these spiders, P. boliviensis, is a medically important species widely distributed in Central and South America, whose behaviour, habitat, venom composition, toxicity and bites on humans have already been paid considerable attention in previous research work. Nevertheless, after examining a large pool of museum specimens, biologists from The George Washington University (N. Hazzi and G. Hormiga) began to wonder if samples named P. boliviensis were actually belonging to one and the same species.

Everything started when N. Hazzi was examining specimens of banana spiders identified in the past by experts as P. boliviensis. The research team quickly realized that the morphological features currently used to identify this species were not sufficient. Then, they discovered two well-defined morphological groups of P. boliviensis that were separated by the Andean mountain range, a geographic barrier that separates many other species.

To prove that these two “forms” were different species, the authors conducted fieldwork in the Amazon, Andes, and Central America, collecting specimens of these venomous spiders to explore if the genomic signal also suggests two species. They discovered that genetic differences separating these two forms were similar compared to the genetic differences separating other recognized species of banana spiders. Using morphological, genomic and geographic distribution data, the authors concluded that P. boliviensis represents not a single species, but two different ones. They uncovered that the true P. boliviensis was only found in the Amazonian region, and the second species, P. depilata (an old name revalidated by the research team), was found in the Andes, Chocó and Caribbean regions. Their findings are published in the open-access, peer-reviewed journal ZooKeys.

To obtain more distribution records for these species, the research team used the citizen science platform iNaturalist. Since the two species are among the few spiders that can be identified using only images, the platform turned out to be a very helpful tool. Data submitted by the iNaturalist community helped identify where the two species of Phoneutria are found. Curiously enough, for these two species, iNaturalist presented higher and more widely distributed records than the scientists’ own database.

“To our knowledge, this is the first study that has used iNaturalist to gather occurrence records on venomous species to estimate distribution models,”
the researchers say.

This is how the two spiders can be distinguished using only photographs: P. boliviensis has two lateral white-yellow bands in the anterior area of the carapace, while P. depilata has four series of yellow dots in the ventral side of the abdomen. In addition, for P. depilata’s identification, information is needed on where the image was taken, because this is the only species of Phoneutria found in the Andes, Chocó, and Central America. However, the most reliable approach to identify these species requires examination under a stereomicroscope.

Interestingly, P. depilata has been mislabeled as P. boliviensis throughout many studies, including works on venom composition and toxicity, ecology, geographic distribution, and human epidemiology of bites. There have been human bite records of this species reported in Costa Rica and in banana plantations in Colombia, most of them with mild to moderate envenomation symptoms. Except for brief anecdotal mentions by field explorers in the Amazon, little is known about P. depilata.

Genetic evolutionary tree of the banana spiders genus *Phoneutria*
Photo by N.Hazzi

The study provides detailed diagnoses with images to distinguish both species and distribution maps.

“This valuable information will help identify risk areas of accidental bites and assist health professionals in determining the identity of the species involved, especially for P. depilata. This is a significant discovery that will affect studies about toxicology, opening new opportunities to compare the venom composition and the effect of these two species,” the authors conclude.

Research article:

Hazzi NA, Hormiga G (2021) Morphological and molecular evidence support the taxonomic separation of the medically important Neotropical spiders Phoneutria depilata (Strand, 1909) and P. boliviensis (F.O. Pickard-Cambridge, 1897) (Araneae, Ctenidae). ZooKeys 1022: 13-50. https://doi.org/10.3897/zookeys.1022.60571

Agents of food-borne zoonoses confirmed to parasitise newly-recorded in Thailand snails

Parasitic flatworms known as agents of food-borne zoonoses were confirmed to use several species of thiarid snails, commonly found in freshwater and brackish environments in southeast Asia, as their first intermediate host. These parasites can cause severe ocular infections in humans who consume raw or improperly cooked fish that have fed on infected snails. The study, conducted in South Thailand by Thai and German researchers and led by Kitja Apiraksena, Silpakorn University, is published in the peer-reviewed open-access journal Zoosystematics and Evolution.

“Trematode infections are major public health problems affecting humans in southeast Asia. Trematode infections depend not only on the habit of people, but also on the presence of first and second intermediate host species, resulting in the endemic spread of parasites, such as intestinal and liver flukes in Thailand”.
explain the scientists.

The snails of concern belong to the genus Stenomelania, have elongated and pointed shells and can be found near and in the brackish water environment of estuaries in the Oriental Region, from India to the Western Pacific islands. Worryingly enough, science does not know much else about these snails to date. Further, these species are hard to distinguish from related trumpet snails, because of the similarities in their shell morphology.

In order to provide some basic knowledge about the parasitic worms in Thailand and neighbouring countries, the research team collected a total of 1,551 Stenomelania snails, identified as four species, from streams and rivers near the coastline of the south of Thailand in Krabi, Trang and Satun Provinces. Of them, ten were infected with trematodes. The parasites were found at seven of the studied localities and belonged to three different species. In Krabi Province, the researchers observed all three species.

Speculating on their presence, the scientists suspect that it could be related to the circulation of sea currents, as the flow of water along the Andaman coast is affected by the monsoon season.

In conclusion, the researchers note that it is a matter of public health that further research looks into the biodiversity and biology of these snails, in order to improve our knowledge about the susceptibility of Stenomelania snails to food-borne zoonotic.

“This finding indicated that the resulting parasitic diseases are still largely neglected in tropical medicine, so further studies should be performed on the prevalence of various trematode-borne diseases in locations with snail occurrences in Thailand,”
they say.

Research article:

Apiraksena K, Namchote S, Komsuwan J, Dechraksa W, Tharapoom K, Veeravechsukij N, Glaubrecht M, Krailas D (2020) Survey of Stenomelania Fisher, 1885 (Cerithioidea, Thiaridae): The potential of trematode infections in a newly-recorded snail genus at the coast of Andaman Sea, South Thailand. Zoosystematics and Evolution 96(2): 807-819. https://doi.org/10.3897/zse.96.59448

Under Extinction Pressure: Rare Australian bee found after 100 years

A widespread field search for a rare Australian native bee (Pharohylaeus lactiferus) that had not been recorded for almost a century found the species has been there all along – but is probably under increasing pressure to survive. Prior to this study, only six individuals had been found, with the last published record of this Australian endemic bee species, from 1923 in Queensland.

Male *Pharohylaeus lactiferus* bee. Photo by James Dorey.

A widespread field search for a rare Australian native bee (Pharohylaeus lactiferus) that had not been recorded for almost a century found the species has been there all along – but is probably under increasing pressure to survive. Prior to this study, only six individuals had been found, with the last published record of this Australian endemic bee species, from 1923 in Queensland.

“This is concerning because it is the only Australian species in the Pharohylaeus genus and nothing was known of its biology,”
Flinders University researcher and biological sciences PhD candidate James Dorey says in the new scientific paper in the peer-reviewed, open-access Journal of Hymenoptera Research.

The ‘hunt’ began after bee experts Olivia Davies and Dr Tobias Smith raised the possibility of the species’ extinction based on the lack of any recent sightings. The ‘rediscovery’ followed an extensive sampling of 225 general and 20 targeted sampling sites across New South Wales and Queensland.

Along with extra bee and vegetation recordings from the Atlas of Living Australia, which lists 500 bee species in New South Wales and 657 in Queensland, the Flinders researchers sought to assess the latest levels of true diversity, warning that habitat loss and fragmentation of Australia’s rainforests, along with wildfires and climate change, are likely to put extinction pressure on this and other invertebrate species.

“Three populations of P. lactiferous were found by sampling bees visiting their favoured plant species along much of the Australian east coast, suggesting population isolation,”
Mr Dorey reports.

Highly fragmented habitat and potential host specialisation might explain the rarity of P. lactiferus.

Additionally, the scientists remind of previous findings that Australia has already cleared more than 40% of its forests and woodlands since European colonisation, leaving much of the remainder fragmented and degraded.

“My geographical analyses used to explore habitat destruction in the Wet Tropics and Central Mackay Coast bioregions indicate susceptibility of Queensland rainforests and P. lactiferus populations to bushfires, particularly in the context of a fragmented landscape,”
Mr Dorey says.

The study also warns the species is even more vulnerable as they appear to favour specific floral specimens and were only found near tropical or sub-tropical rainforest – a single vegetation type.

“Collections indicate possible floral and habitat specialisation with specimens only visiting firewheel trees (Stenocarpus sinuatu), and Illawarra flame trees (Brachychiton acerifolius), to the exclusion of other available floral resources.”

Known populations of P. lactiferus remain rare and susceptible to habitat destruction (e.g. caused by changed land use or events such as fires), the paper concludes.

“Future research should aim to increase our understanding of the biology, ecology and population genetics of P. lactiferus.”

Female *Pharohylaeus lactiferus* bee. Photo by James Dorey.

“If we are to understand and protect these wonderful Australian species, we really need to increase biomonitoring and conservation efforts, along with funding for the museum curation and digitisation of their collections and other initiatives,”
Mr Dorey says.

Research paper:

Dorey JB (2021) Missing for almost 100 years: the rare and potentially threatened bee, Pharohylaeus lactiferus (Hymenoptera, Colletidae). Journal of Hymenoptera Research 81: 165-180. https://doi.org/10.3897/jhr.81.59365

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Guest blog post: Unique feeding behaviour of Asian kukri snakes gutting frogs and toads

Guest blog post by Henrik Bringsøe

In September 2020, we reported the first evidence for a newly discovered behaviour in snakes, as we provided extensive photographic documentation, demonstrating a macabre feeding strategy of Asian kukri snakes of the species Oligodon fasciolatus, the Small-banded Kukri Snake: a snake cutting open the abdomen of a toad, inserting its head and pulling out the toad’s organs which are then swallowed.

A Small-banded Kukri Snake attacking a Painted Burrowing Frog, which is inflating its lungs. The snake makes rotations about its own longitudinal body axis (“death rolls”), as it is biting and holding the belly of the frog. Video by Navapol Komanasin.

This is done while the toad is alive and it may take several hours before it dies! We have now provided new evidence that two other species of kukri snakes also exhibit this highly unusual behaviour: Oligodon formosanus, the Taiwanese Kukri Snake, and Oligodon ocellatus, the Ocellated Kukri Snake. These three species are closely-related and belong to the same species group in the genus Oligodon.

On two occasions in Hong Kong, a Taiwanese Kukri Snake was observed eviscerating frogs of the species Kaloula pulchra, the Painted Burrowing Frog or Banded Bullfrog. In one case, the snake had cut open the belly of the frog and inserted its head deep into the frog’s abdomen. In this position, the snake performed repeated rotations about its own longitudinal body axis, also called “death rolls”! We believe that the purpose of these death rolls was to tear out organs to be subsequently swallowed. In the other case, the organs of the frog had been forced out of its abdomen.

A Taiwanese Kukri Snake with its head buried deep into the abdomen of a Painted Burrowing Frog. Initially, the frog moves its long fourth toe of the left hind foot up and down 21 times. During the subsequent active struggle, the snake makes three “death rolls”. Video by Jonathan Rotbart.

A Small-banded Kukri Snake was also observed eating a Painted Burrowing Frog in Northeast Thailand, but it swallowed the frog whole. That snake also performed death rolls, although we have never before seen that behaviour in this species of kukri snake (this species was treated in our 2020 paper). This frog is not considered toxic and is also eaten by other snakes. We believe that prey size is crucial in determining whether the gape width allows large prey to be swallowed whole by kukri snakes. If the prey is too large, the snake may eviscerate a frog or toad, in order to swallow the organs. Afterwards, the snake will perhaps be able to swallow the rest of the frog or toad.

In another new paper, we describe and illustrate the Ocellated Kukri Snake eating the toxic toad Asian Black-spotted Toad (Duttaphrynus melanostictus) in Vietnam. Initially, the large snake’s head was buried past its eyes into the abdomen of the toad, but eventually the snake swallowed the toad whole despite its toxicity. We interpret this behaviour that kukri snakes are in fact resistant to the toads’ cardiac glycoside toxins. Furthermore, toads are only eviscerated if they prove too large to be swallowed whole.

An Ocellated Kukri Snake first pierced this poisonous Asian common toad and buried its head deeply into the abdomen of the amphibian, as it was probably eating the organs. However, as seen in the photo, the kukri snake proceeded to swallow the toad whole.
Photo by James Holden.

We suggest that the unique behaviour of eviscerating frogs and toads and eating their organs may have evolved specifically in a group of kukri snakes named the Oligodon cyclurus group or clade because it has now been recorded in three of its species, namely Oligodon fasciolatus, Oligodon formosanus and Oligodon ocellatus. We hope that future observations may uncover additional aspects of the fascinating feeding habits of kukri snakes though we may indeed call them gruesome.

See more video recordings of the snakes’ unique, even if quite gruesome, behaviours provided as supplementary files to one of the discussed research papers.

Follow Herpetozoa on Twitter and Facebook.

Research papers:

Bringsøe H, Suthanthangjai M, Suthanthangjai W, Lodder J, Komanasin N (2021) Gruesome twosome kukri rippers: Oligodon formosanus (Günther, 1872) and O. fasciolatus (Günther, 1864) eat Kaloula pulchra Gray, 1831 either by eviscerating or swallowing whole. Herpetozoa 34: 49-55. https://doi.org/10.3897/herpetozoa.34.e62688

Bringsøe H, Holden J (2021) Yet another kukri snake piercing an anuran abdomen: Oligodon ocellatus (Morice, 1875) eats Duttaphrynus melanostictus (Schneider, 1799) in Vietnam. Herpetozoa 34: 57-59. https://doi.org/10.3897/herpetozoa.34.e62689

New DNA barcoding project aims at tracking down the “dark taxa” of Germany’s insect fauna

**New dynamic article collection at Biodiversity Data Journal is already accumulating the project’s findings**

About 1.4 million species of animals are currently known, but it is generally accepted that this figure grossly underestimates the actual number of species in existence, which likely ranges between five and thirty million species, or even 100 million.

Meanwhile, a far less well-known fact is that even in countries with a long history of taxonomic research, such as Germany, which is currently known to be inhabited by about 48,000 animal species, there are thousands of insect species still awaiting discovery. In particular, the orders Diptera (flies) and Hymenoptera (especially the parasitoid wasps) are insect groups suspected to contain a strikingly large number of undescribed species. With almost 10,000 known species each, these two insect orders account for approximately two-thirds of Germany’s insect fauna, underlining the importance of these insects in many ways.

The conclusion that there are not only a few, but so many unknown species in Germany is a result of the earlier German Barcode of Life projects: GBOL I and GBOL II, both supported by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF) and the Bavarian Ministry of Science under the project Barcoding Fauna Bavarica.

In its previous phases, GBOL aimed to identify all German species reliably, quickly and inexpensively using DNA barcodes. Since the first project was launched twelve years ago, more than 25,000 German animal species have been barcoded. Among them, the comparatively well-known groups, such as butterflies, moths, beetles, grasshoppers, spiders, bees and wasps, showed an almost complete coverage of the species inventory.

In 2020, another BMBF-funded DNA barcoding project, titled GBOL III: Dark Taxa, was launched, in order to focus on the lesser-known groups of Diptera and parasitoid Hymenoptera, which are often referred to as “dark taxa”. The new project commenced at three major German natural history institutions: the Zoological Research Museum Alexander Koenig (Bonn), the Bavarian State Collection of Zoology (SNSB, Munich) and the State Museum of Natural History Stuttgart, in collaboration with the University of Würzburg and the Entomological Society Krefeld. Together, the project partners are to join efforts and skills to address a range of questions related to the taxonomy of the “dark taxa” in Germany.

As part of the initiative, the project partners are invited to submit their results and outcomes in the dedicated GBOL III: Dark Taxa article collection in the peer-reviewed, open-access Biodiversity Data Journal. There, the contributions will be published dynamically, as soon as approved and ready for publication. The articles will include taxonomic revisions, checklists, data papers, contributions to methods and protocols, employed in DNA barcoding studies with a focus on the target taxa of the project.

“The collection of articles published in the Biodiversity Data Journal is an excellent approach to achieving the consortium’s goals and project partners are encouraged to take advantage of the journal’s streamlined publication workflows to publish and disseminate data and results that were generated during the project,”
says the collection’s editor Dr Stefan Schmidt of the Bavarian State Collection of Zoology.

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Find and follow the dynamic article collection GBOL III: Dark Taxa in Biodiversity Data Journal.

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Failure to respond to a coral disease epizootic in Florida: causes and consequences

By 2020, losses of corals have been observed throughout Florida and into the greater Caribbean basin in what turned out to be likely the most lethal recorded case of Stony Coral Tissue Loss Disease. A Perspectives paper, published in the open-access peer-reviewed journal Rethinking Ecology, provides an overview of how Florida ended up in a situation, where the best that could be done is rescuing genetic material from coral species at risk of regional extinction.

Guest blog post by William F. Precht

A colony of the large grooved brain coral, Colpophyllia natans, infected by Stony Coral Tissue Loss Disease. The photo shows the progressive, rapid advance of disease, left-to-right, across the colony.
Image by William Precht.

Dredging projects conducted in association with coral reefs typically generate concern by environmental groups, resulting in careful monitoring by government agencies. Even though the aim of those dredge projects is to widen or deepen existing ship channels, while minimizing damage to coral reef resources, there are often the intuitive negative assumptions that dredging kills corals.

The recent Port Miami Dredge Project started as an uncomplicated case story. However, significant problems arose, caused by a concurrent and unprecedented coral disease epidemic that killed large numbers of corals, which was initiated following a regional thermal anomaly and coral bleaching event.

The coral disease, known as Stony Coral Tissue Loss Disease (SCTLD), was first observed in September 2014 near Virginia Key, Florida. In roughly six years, the disease has spread throughout Florida and into the greater Caribbean basin. The high prevalence of SCTLD and the resulting high mortality in coral populations, coupled with the large number of susceptible species affected, suggest that this disease outbreak is one of the most lethal ever recorded on contemporary coral reefs. The disease is still presently active and continues to ravage coral reefs throughout the region.

The initial response to this catastrophic disease by resource managers with purview over the ecosystem in Southeast Florida was slow. There is generally a noticeably short window of opportunity to intervene in disease amelioration or eradication in the marine environment. This slow response enabled the disease to spread unchecked. Why was the response to the loss of our coral reefs to a coral disease epidemic such a massive failure? This includes our failure as scientists, regulators, resource managers, local media, and policy makers alike. With this Perspectives paper, published in Rethinking Ecology, my intention was to encapsulate the numerous reasons for our failures during the first few years of the outbreak, reminiscent of the early failures in the U.S. response to the COVID-19 pandemic.

First, the Port Miami dredging project was ongoing when the coral disease epidemic began. Some managers and local environmental groups blamed dredging, rather than SCTLD for the coral losses, reported in the project’s compliance monitoring program. Second, this blame was amplified in the media, because dredging projects are intuitively assumed to be bad for coral reefs. Third, during this same time, the State of Florida prohibited government employees from acknowledging global warming in their work. This was problematic because ocean warming is a proximal cause of many coral diseases.

As a result, some managers ignored the well-known links between warming and coral disease. A consequence of this policy was that the dredging project provided an easy target to blame for the coral mortality noted in the monitoring program, despite convincing data that suggested otherwise.

Specifically, the intensive compliance monitoring program, conducted by trained scientific divers, was statistically significant. SCTLD that was killing massive numbers of corals throughout the region was also killing corals at the dredge site. Further, this was happening in the same proportions and among the same suite of species.

Finally, when the agencies responded to the outbreak, their efforts were too little and much too late to make a meaningful difference. While eradication of the disease was never a possibility, early control measures may have slowed its spread, or allowed for the rescue of significant numbers of large colonies of iconic species. Because of the languid management response to this outbreak, we are now sadly faced with a situation where much of our management efforts are focused on the rescue of genetic material from coral species already at risk of regional extinction.

The delayed response to this SCTLD outbreak in Southeast Florida has many similarities to the COVID-19 pandemic response in the United States and there are lessons learned from both that will improve disease response outcomes in the future, to the benefit of coral reefs and human populations.

Publication:

Precht W (2021) Failure to respond to a coral disease epizootic in Florida: causes and consequences. Rethinking Ecology 6: 1-47. https://doi.org/10.3897/rethinkingecology.6.56285

Eurasian eagle owl diet reveals new records of threatened giant bush-crickets

Bird diets provide a real treasure for research into the distribution and conservation of their prey, conclude scientists after studying the Eurasian Eagle Owl in southeastern Bulgaria. In their paper, published in the open-access, peer-reviewed journal Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa”, they report the frequent presence of the threatened Big-Bellied Glandular Bush-Cricket, and conclude that studies on the Eurasian Eagle Owl could be used to identify biodiversity-rich areas in need of protection.

Male specimen of the Big-Bellied Glandular Bush-Cricket (Bradyporus macrogaster)
Photo by Dragan Chobanov

Bird diets provide a real treasure for research into the distribution and conservation of their prey, such as overlooked and rare bush-cricket species, point out scientists after studying the diet of the Eurasian Eagle Owl (Bubo bubo) in southeastern Bulgaria.

In their paper, published in the open-access, peer-reviewed journal Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa”, Dr Dragan Chobanov (Institute of Biodiversity and Ecosystem Research, Bulgaria) and Dr Boyan Milchev (University of Forestry, Bulgaria) report the frequent presence of the threatened with extinction Big-Bellied Glandular Bush-Cricket (Bradyporus macrogaster) in the diet of Eurasian Eagle Owls, and conclude that the predatory bird could be used to identify biodiversity-rich areas in need of protection.

While the Balkan Peninsula has already been recognised as the area with the highest diversity of orthopterans (grasshoppers, crickets and bush-crickets) in Europe and one of the generally most biologically diverse areas in the whole Palearctic realm, it is also home to a worrying number of threatened species. Additionally, a thorough and updated country assessment of the conservation status of the orthopterans found in Bulgaria is currently lacking. This is why the Bulgarian team undertook a study on the biodiversity of these insects by analysing food remains from pellets of Eurasian Eagle Owls, collected from 53 breeding sites in southeastern Bulgaria.

As a result, the scientists reported three species of bush crickets that have become a significant part of the diet of the studied predatory birds. Curiously enough, all three species are rare or threatened in Bulgaria. The case of the Big-Bellied Glandular Bush-Cricket is of special concern, as it is a species threatened by extinction. Meanwhile, the local decline in mammals and birds that weigh between 0.2 and 1.9 kg, which are in fact the preferred prey for the Eurasian Eagle Owl, has led the highly opportunistic predator to increasingly seek large insects for food. The researchers even suspect that there might be more overlooked species attracting the owls.

Taking into account the hereby reported interconnected inferences of conservation concern, as well as the vulnerability of the Big-Bellied Glandular Bush-Cricket, a species with a crucial role in the food chain, the scientists call for the newly provided data to prompt the designation of a new Natura 2000 site. Additionally, due to the species’ requirements for habitats of low disturbance and high vegetation diversity, and its large size and easy location via singing males, they point out that it makes a suitable indicator for habitat quality and species community health.

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Original source:

Chobanov D, Milchev B (2020) Orthopterans (Insecta: Orthoptera) of conservation value in the Eurasian Eagle Owl Bubo bubo food in Bulgaria. Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 63(2): 161-167. https://doi.org/10.3897/travaux.63.e53867

King of the Cave: New centipede on top of the food chain in the sulphurous-soaked Movile

A new species of endemic, troglobiont centipede was discovered by an international team of scientists in the Romanian cave Movile: a unique underground ecosystem, isolated several millions years ago during the Neogene, whose animal life only exists because of the chemosynthetic bacteria. As the largest Movile’s inhabitant, the new species can easily be crowned as the ‘king’ of this ‘hellish’ ecosystem. Aptly named Cryptops speleorex, the cave-dweller is described in the open-access, peer-reviewed journal ZooKeys.

A photo of the newly discovered species (*Cryptops speleorex*), the largest inhabitant of the Movile cave (Romania) known to date
Photo by Mihai Baciu

Deemed to never see the light of the day, a new species of endemic, troglobiont centipede was discovered by an international team of scientists in the Romanian cave Movile: a unique underground ecosystem, where the oxygen in the air might be half of the amount of what we’re used to, yet the sulphurous abounds; and where the animal life only exists because of chemosynthetic bacteria feeding on carbon dioxide and methane.

This hellish ecosystem–where breathing alone could be lethal for most of us–seems to have finally crowned its king. At a size of between 46 and 52 mm in length, the centipede Cryptops speleorex is the largest of the cave’s inhabitants known to date. The new species is described in the open-access, peer-reviewed journal ZooKeys.

Already isolated from the outside world several millions years ago during the Neogene, the Movile cave has been drawing the attention of scientists ever since its unexpected discovery in 1986 by Romanian workers, searching for locations suitable for building a power plant in the southeastern parts of the country.

Surprisingly enough, despite its harsh living conditions, the Movile ecosystem was soon found to harbor a diverse and unique fauna, characterised by exceptional species endemism and specific trophic links. So far, the cave has been known to give home to the troglobiont water scorpion, liocranid and nesticid spiders, cave leeches and certainly many more yet to be discovered.

In fact, it was long thought that this unique underground ecosystem was also inhabited by surface-dwelling species widespread in Europe. Convinced that this scenario is highly unlikely, scientists Dr Varpu Vahtera (University of Turku, Finland), Prof Pavel Stoev (National Museum of Natural History, Bulgaria) and Dr Nesrine Akkari (Museum of Natural History Vienna, Austria) decided to examine a curious centipede, collected by speleologists Serban Sarbu and Alexandra Maria Hillebrand, during their recent expedition to Movile.

“Our results confirmed our doubts and revealed that the Movile centipede is morphologically and genetically different, suggesting that it has been evolving from its closest surface-dwelling relative over the course of millions of years into an entirely new taxon that is better adapted to life in the never-ending darkness,” explain the researchers.

“The centipede we described is a venomous predator, by far the largest of the previously described animals from this cave. Thinking of its top rank in this subterranean system, we decided to name the species Cryptops speleorex, which can be translated to the “King of the cave”, they add.

The scientists exploring the Movile cave (Romania)
Photo by Mihai Baciu

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Original Source:

Vahtera V, Stoev P, Akkari N (2020) Five million years in the darkness: A new troglomorphic species of Cryptops Leach, 1814 (Chilopoda, Scolopendromorpha) from Movile Cave, Romania. ZooKeys 1004: 1-26. https://doi.org/10.3897/zookeys.1004.58537

Scientists took a rare chance to prove we can quantify biodiversity by ‘testing the water’

Recent study conducted at a UK fishery farm provides new evidence that DNA from water samples can accurately determine fish abundance and biomass

Organisms excrete DNA in their surroundings through metabolic waste, sloughed skin cells or gametes, and this genetic material is referred to as environmental DNA (eDNA).

As eDNA can be collected directly from water, soil or air, and analysed using molecular tools with no need to capture the organisms themselves, this genetic information can be used to report biodiversity in bulk. For instance, the presence of many fish species can be identified simultaneously by sampling and sequencing eDNA from water, while avoiding harmful capture methods, such as netting, trapping or electrofishing, currently used for fish monitoring.

While the eDNA approach has already been applied in a number of studies concerning fish diversity in different types of aquatic habitats: rivers, lakes and marine systems, its efficiency in quantifying species abundance (number of individuals per species) is yet to be determined. Even though previous studies, conducted in controlled aquatic systems, such as aquaria, experimental tanks and artificial ponds, have reported positive correlation between the DNA quantity found in the water and the species abundance, it remains unclear how the results would fare in natural environments.

However, a research team from the University of Hull together with the Environment Agency (United Kingdom), took the rare opportunity to use an invasive species eradication programme carried out in a UK fishery farm as the ultimate case study to evaluate the success rate of eDNA sampling in identifying species abundance in natural aquatic habitats. Their findings were published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics.

“Investigating the quantitative power of eDNA in natural aquatic habitats is difficult, as there is no way to ascertain the real species abundance and biomass (weight) in aquatic systems, unless catching all target organisms out of water and counting/measuring them all,”
explains Cristina Di Muri, PhD student at the University of Hull.

Drained pond after fish translocation.
Photo by Dr. Watson H.V.

During the eradication, the original fish ponds were drained and all fish, except the problematic invasive species: the topmouth gudgeon, were placed in a new pond, while the original ponds were treated with a piscicide to remove the invasive fish. After the eradication, the fish were returned to their original ponds. In the meantime, all individuals were counted, identified and weighed from experts, allowing for the precise estimation of fish abundance and biomass.

“We then carried out our water sampling and ran genetic analysis to assess the diversity and abundance of fish genetic sequences, and compared the results with the manually collected data. We found strong positive correlations between the amount of fish eDNA and the actual fish species biomass and abundance, demonstrating the existence of a strong association between the amount of fish DNA sequences in water and the actual fish abundance in natural aquatic environments,”
reports Di Muri.

Environmental DNA sampling using water collection bottles
Photo by Dr. Peirson G.

The scientists successfully identified all fish species in the ponds: from the most abundant (i.e. 293 carps of 852 kg total weight) to the least abundant ones (i.e. one chub of 0.7 kg), indicating the high accuracy of the non-invasive approach.

“Furthermore, we used different methods of eDNA capture and eDNA storage, and found that results of the genetic analysis were comparable across different eDNA approaches. This consistency allows for a certain flexibility of eDNA protocols, which is fundamental to maintain results comparable across studies and, at the same time, choose the most suitable strategy, based on location surveyed or resources available,”
elaborates Di Muri.

“The opportunity of using eDNA analysis to accurately assess species diversity and abundance in natural environments will drive a step change in future species monitoring programmes, as this non-invasive, flexible tool is adaptable to all aquatic environments and it allows quantitative biodiversity surveillance without hampering the organisms’ welfare.”

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Original publication:

Di Muri C, Lawson Handley L, Bean CW, Li J, Peirson G, Sellers GS, Walsh K, Watson HV, Winfield IJ, Hänfling B (2020) Read counts from environmental DNA (eDNA) metabarcoding reflect fish abundance and biomass in drained ponds. Metabarcoding and Metagenomics 4: e56959. https://doi.org/10.3897/mbmg.4.56959