EU responsible for extinction domino effect on frog populations

New study shows EU frogs’ legs imports put a serious risk to frogs in Southeast Asia and Eastern Europe

In Europe, frogs’ legs are mostly offered as appetizers. © Pixabay

Between 2010 and 2019, total imports of frog’s legs into the EU numbered 40.7 million kg, which equals to up to roughly 2 billion frogs. While Belgium is the main importer, France is the main consumer. These insights are part of a new study, published in the journal Nature Conservation, which found “inexplicable volatility” in the trade of frog legs and an extreme dependency of the EU on other countries to meet its demand.

Leading author Dr. Auliya of the Leibniz Institute for the Analysis of Biodiversity Change in Bonn, Germany, outlines the manifold uncertainties underlying this trade: “The international trade in frogs’ legs is a black box, whether it is the lack of species-specific trade data, which would be needed to ensure sustainability, or the large-scale mislabeling in trade and the challenges to identify species when it comes to processed, skinned and frozen frogs’ legs.”

Frogs’ legs from large ranids at a large-scale reptile collector in North Sumatra, Indonesia. Photo by Mark Auliya

Frogs have a central role in the ecosystem as insect predators – and where frogs disappear, the use of toxic pesticides increases. Hence, the frogs’ legs trade has direct consequences not only for the frogs themselves, but for biodiversity and ecosystem health as a whole. The extent to which pesticide residues in frogs’ legs are traded internationally remains unclear.

In the 1970s and 1980s, India and Bangladesh were the top suppliers of frogs’ legs to Europe, but when their wild frog populations collapsed, both countries banned exports. Since then, Indonesia has taken over as the largest supplier. In the Southeast Asian country, as now also in Turkey and Albania, large-legged frog species are dwindling in the wild, one after the other, causing a fatal domino effect for species conservation. This increasingly threatens frog populations in the supplier countries.

“The EU is by far the world’s largest importer of frogs’ legs, and large-legged species such as the crab-eating grass frog (Fejervarya cancrivora), the giant Javan frog (Limnonectes macrodon) and the East Asian bullfrog (Hoplobatrachus rugulosus) are in particular demand among supposed gourmets in Europe”, points out co-author Dr. Sandra Altherr, a biologist and wildlife trade expert of the Germany-based charity Pro Wildlife.                                         

Frozen frogs’ legs on sale in a French supermarket, August 2022. Photo by Sandra Altherr / Pro Wildlife

While commercial frog farms, like those operated in Viet Nam, may at first glance seem to be an alternative that can relieve the pressure from wild frog populations, ongoing restocking of frog farms with native species from the wild and, in the case of non-native species, such as the American bullfrog (Lithobates catesbeianus) the risk of escape, invasion and potential risk of disease spread, are serious risks for the environment.

The harvest of wild frog populations and species produced at commercial frog farms for the purpose of consumption also leaves disease control and hygiene measures by the wayside; additionally, the cross-border trade of species for consumption has led to genetic pollution and hybridization between species.  

Limnonectes blythii species complex from a large-scale collector in North Sumatra. Photo by Mark Auliya

„During the course of this study, it became clear just how difficult it is to obtain concrete data on the current international trade in frogs’ legs. Specifically, relevant data are scattered across different unconnected databases,“ the researchers write in their paper.

In the course of their review, they were not able to find any published data out whether pesticide residues and other potentially toxic substances in (processed) frogs or their legs imported into the EU have been monitored. “This in itself is shocking and in view of the situation in exporting countries and the lack of transparency and management in the application of agrochemicals and veterinary medicinal substances within commercial farms, we strongly recommend that this monitoring become an urgent near-future task for importing countries,” they write.

“The complexity of issues underlying the frogs’ legs trade is not a priority policy item for the EU,” the authors conclude. They add that a listing of the most-affected frog species under CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, would help to monitor trade and ensure its sustainability, and the EU as the main destination should take the lead on that.

Research article:

Auliya M, Altherr S, Nithart C, Hughes A, Bickford D (2023) Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer. Nature Conservation 51: 71-135. https://doi.org/10.3897/natureconservation.51.93868

Follow Nature Conservation on Facebook and Twitter.

Endemic frogs in Himalayan region exhibit site fidelity

The Murree Hills Frog and Hazara Torrent Frog show minimum movement out of their habitat, which makes them more unique from an ecology and conservation perspective

Amongst tetrapods, amphibians entail the highest number of threatened and data deficient species, which has put them in the limelight of research in animal ecology and conservation. Endemic species have evolved and adapted to a particular set of environmental conditions. Hence, these are more vulnerable to environmental changes and are susceptible to population declines because of their restricted distribution ranges.

Murree Hills Frog (Nanorana vicina). Photo by Herpetology Lab, Arid Agriculture University, Rawalpindi

The Murree Hills Frog and Hazara Torrent Frog are endemic to Pakistan and South Asian countries. They are associated with the torrential streams and nearby clear water pools situated at high elevation. These frogs are susceptible to threats like habitat degradation, urbanization, and climate change. A recent study published in the-open access journal Biodiversity Data Journal reports that these endemic frogs do not show much movement within and outside their habitat.

Hazara Torrent Frog (Allopaa hazarensis). Photo by Herpetology Lab, Arid Agriculture University, Rawalpindi

“We have, for the first time, used radio-transmitters (VHF) on frogs endemic to Himalayan region to understand their ecology,” explains Dr. Muhammad Rais, Assistant Professor at the Herpetology Lab in the Arid Agriculture University, Rawalpindi, and lead author of the study. “Surprisingly, the Murree Hills Frog and Hazara Torrent Frog depend heavily for their survival on particular stream(s).”

“We suggest carrying out additional long term studies by incorporating multiple adjacent stream systems to better understand dispersal and colonization in these frogs,” he says in conclusion.

Research article:

Akram A, Rais M, Saeed M, Ahmed W, Gill S, Haider J (2022) Movement Paradigm for Hazara Torrent Frog Allopaa hazarensis and Murree Hills Frog Nanorana vicina (Anura: Dicroglossidae). Biodiversity Data Journal 10: e84365. https://doi.org/10.3897/BDJ.10.e84365

Tadpoles for dinner? Indigenous community in Mexico reveals a favorite recipe for a particular frog

Tadpoles of the Sierra Juarez brook frog Duellmanohyla ignicolor are consumed in caldo de piedra in the Chinantla region, in Oaxaca, Mexico.

Stone soup (caldo de piedra) is a traditional meal from the Indigenous Chinantla region in the state of Oaxaca, Mexico. Prepared by men, it is made by placing tomato, cilantro, chili peppers, onion, raw fish, salt, and water in a jicara (a bowl made from the fruit of the calabash tree) in a hole dug near a river. Then, the ingredients are cooked by adding red hot rocks to the “pot”.

In 2019, members of the CIIDIR-Oaxaca Amphibian Ecology Laboratory visited Santa Cruz Tepetotutla in the Chinantla region as part of their continued research work in the community’s forests and streams. 

“As we observed and recorded the presence of tadpoles, our guide, Mr. Pedro Osorio-Hernández, remarked that one such tadpole was eaten in stone soup”, says Dr Edna González Bernal, one of the researchers.

Local landscape. Photo by Carlos A. Flores

Although not much attention is paid to tadpoles, they are more important than you might think. They are perfect indicators of the health of bodies of water, due to their sensitivity to changes in the aquatic environment where they develop. When tadpoles are present in a stream, river, or even a puddle, they indicate an acceptable concentration of oxygen, pH, conductivity, and temperature, or overall good dynamics of sediments and plant matter. And, above all, finding tadpoles is the easiest way to know about the presence of an amphibian species that reproduces in that site, regardless of whether or not an adult has been observed. Hence, the identification of the unique characteristics of the tadpoles of each species is an important task that is currently drawing more attention amongst scientists. 

Duellmanohyla ignicolor tadpoles. Photo by Edna González-Bernal

“For us, as Oaxacans, Don Pedro’s words were an eye-opener”, biologist Carlos A. Flores, also part of the study,  continues. “Although we knew about the tradition of stone soup, we would have never imagined that it could be prepared with tadpoles of the Sierra Juárez Brook frog (Duellmanohyla ignicolor)!”

Duellmanohyla ignicolor. Photo by Edna González-Bernal

“As scientists, we wondered: why this species and not another? Since when have these tadpoles been eaten? In what other places are tadpoles consumed and in what form? Does this consumption have a negative effect on amphibian populations?”

To answer these questions, the researchers monitored several streams in the community, collecting data on the structure of these sites, such as depth, water velocity, temperature, etc. They wanted to identify the characteristics of the habitat where the tadpoles of this little known species are found. Their research was recently published in the open-access journal ZooKeys.

The team’s primary interest in the stone soup with tadpoles was to accurately document human interaction with this amphibian species. 

“It is common in anthropological literature to document the consumption of tadpoles in Mexico, but rarely does such documentation reach the species level. Even in some ethnoherpetological works, the consumption of tadpoles is mentioned only anecdotally”, Dr González Bernal explains.  

A boy collects tadpoles. Photo by Edna González-Bernal

“We learned that these larvae tend to form schools: aggregations of several tens to hundreds of individuals. They swim on the surface of the water and move their mouths to feed on suspended particles, which may be remains of plant matter, pollen or insect parts”, she continues. 

“This behavior, as has been documented in other species, biologically implies a strategy to feed more efficiently, control body temperature, protect themselves from predators and even to encourage social interaction. At the same time, it makes it easier for humans to capture several tadpoles using nets, hats, bags or even their own hands.”

This tadpole soup is consumed during the hottest months (April and May), when people go swimming in the river. The rest of the year, it is prepared with fish. Local people described the tadpoles as having a delicious fish-like flavor.

Why do people eat these particular tadpoles? Community members remarked that, because they are found at the surface of the water, they are considered cleaner than those found at the bottom, such as the tadpoles of the the coastal toad (Incilius valliceps) and the gloomy mountain frog (Ptychohyla zophodes). In addition, the tadpoles consumed in the stone broth reach sizes of up to 5 centimeters, which makes them a better choice for the dish.

Tadpoles caught using caps. Photo by Edna González-Bernal

Is stone soup a dish that only exists in the Chinantla region? “We found that while the dish has primarily been documented in this region, it is also consumed in some Indigenous Ayuk (Mixe) municipalities,” Dr González Bernal says. 

The cooking principle itself is a technique that has been used throughout history by different cultures around the world. The particularity of the caldo de piedra lies in its preparation with tomato, cilantro, and chili peppers, as well as prawns or particular species of fish such as the bobo (Joturus prichardi).

In the case of the Sierra Juarez Brook frog’s tadpoles, the researchers concluded that since they are consumed locally and for non-commercial purposes, the species is not at risk. However, the behavior of these tadpoles and their preference for deeper water bodies make them vulnerable to being caught in large quantities.

“In the context of the global amphibian crisis, it is of utmost importance to continue increasing our knowledge about the diversity of species and above all to delve deeper into their ecology, both at the adult and larval stages. Only in this way can we gain a greater understanding of each species’ needs and develop conservation strategies that take into account the biology of species with a complex life cycle, such as amphibians”, the research team says in conclusion. 

Research article:

Flores CA, Arreortúa M, González-Bernal E (2022) Tadpole soup: Chinantec caldo de piedra and behavior of Duellmanohyla ignicolor larvae (Amphibia, Anura, Hylidae). ZooKeys 1097: 117-132. https://doi.org/10.3897/zookeys.1097.76426

Simplified method to survey amphibians will aid conservation

Researchers developed a method to determine which amphibians inhabit a specific area. The new technique will resolve some of the issues with conventional methods, such as capture and observational surveys.

Ryukyu Sword Tailed Newt, or Firebellied Newt. Photo by Neil Dalphin via Creative Commons CC0.

An international collaborative research group of members from seven institutions has developed a method to determine which amphibians (frogs, newts and salamanders) inhabit a specific area. Their work was published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics (MBMG).

To do so, the scientists amplified and analysed extra-organismal DNA (also known as environmental DNA or eDNA) found in the water. This DNA ends up in the water after being expelled from the amphibian’s body along with mucus and excrement. 

The research group included Postdoctoral Researcher Sakata K. Masayuki and Professor Minamoto Toshifumi (Kobe University), Associate Professor Kurabayashi Atsushi (Nagahama Institute of Bio-Science and Technology), Nakamura Masatoshi (IDEA Consultants, Inc.) and Associate Professor Nishikawa Kanto (Kyoto University). 

The newly developed technique will resolve some of the issues with conventional methods, such as capture and observational surveys, which require a specialist surveyor who can visually identify species. Conventional surveys are also prone to discrepancies due to environmental factors, such as climate and season.

The researchers hope that the new method will revolutionise species monitoring, as it will enable anyone to easily monitor the amphibians that inhabit an area by collecting water samples.  

While monitoring in general is crucial to conserve the natural ecosystems, the importance of surveying amphibians is even more pressing, given the pace of their populations’ decline.

Amongst major obstacles to amphibian monitoring, however, are the facts that they are nocturnal; their young (e.g. tadpoles) and adults live in different habitats; and that specialist knowledge is required to capture individuals and identify their species. These issues make it particularly difficult to accurately survey amphibians in a standardised way, and results of individual efforts often contradict each other.

On the other hand, eDNA analysis techniques have already been established in programmes targeted at monitoring fish species, where they are already commonplace. So, the researchers behind the present study joined forces to contribute towards the development of a similar standardised analysis method for amphibians.

First of all, the researchers designed multiple methods for analysing the eDNA of amphibians and evaluated their performance to identify the most effective method. Next, they conducted parallel monitoring of 122 sites in 10 farmlands across Japan using the developed eDNA analysis along with the conventional methods (i.e. capture surveys using a net and observation surveys). 

As a result, the newly developed method was able to detect all three orders of amphibians: Caudata (the newts and salamanders), Anura (the frogs), and Gymnophiona (the caecilians). 

Furthermore, this novel eDNA analysis method was able to detect more species across all field study sites than the conventional method-based surveys, indicating its effectiveness.

Research Background

Amphibian biodiversity is continuing to decline worldwide and collecting basic information about their habitats and other aspects via monitoring is vital for conservation efforts. Traditional methods of monitoring amphibians include visual and auditory observations, and capture surveys.

However, amphibians tend to be small in size and many are nocturnal. The success of surveys varies greatly depending on the climate and season, and specialist knowledge is required to identify species. Consequently, it is difficult to monitor a wide area and assess habitats. The last decade has seen the significant development of environmental DNA analysis techniques, which can be used to investigate the distribution of a species by analysing external DNA (environmental DNA) that is released into the environment along with an organism’s excrement, mucus and other bodily fluids. 

The fundamentals of this technique involve collecting water from the survey site and analysing the eDNA contained in it to find out which species inhabit the area. In recent years, the technique has gained attention as a supplement for conventional monitoring methods. Standardised methods of analysis have already been established for other species, especially fishes, and diversity monitoring using eDNA is becoming commonplace. 

However, eDNA monitoring of amphibians is still at the development stage. One reason for this is that the proposed eDNA analysis method must be suitable for the target species or taxonomic group, and there are still issues with developing and implementing a comprehensive method for detecting amphibians. If such a method could be developed, this would make it possible for monitoring to be conducted even by people who do not have the specialised knowledge to identify species nor surveying experience.

Hopefully, this would be established as a unified standard for large-scale monitoring surveys, such as those on a national scale. This research group’s efforts to develop and evaluate analysis methods will hopefully lay the foundations for eDNA analysis to become a common tool for monitoring amphibians, as well as fish. 

***

Follow Metabarcoding and Metagenomics (MBMG) journal on Twitter and Facebook.

***

Research article: 

Sakata MK, Kawata MU, Kurabayashi A, Kurita T, Nakamura M, Shirako T, Kakehashi R, Nishikawa K, Hossman MY, Nishijima T, Kabamoto J, Miya M, Minamoto T (2022) Development and evaluation of PCR primers for environmental DNA (eDNA) metabarcoding of Amphibia. Metabarcoding and Metagenomics 6: e76534. https://doi.org/10.3897/mbmg.6.76534

Pakistan’s amphibians need more research efforts and better protection

In Pakistan, amphibians have long been neglected in wildlife conservation, management decisions and research agendas. To counter this, scientists have now published the first comprehensive study on all known amphibian species in the country in the open-access scholarly journal ZooKeys. The little we currently know about the occurrence of the chytrid fungus, which has already eradicated many amphibian species globally, is a grim example of how urgent it is to acquire further information.

Amphibians are bioindicators of an ecosystem’s health and may also serve as biological control of crop and forest pests. The First Herpetological Congress, organized in 1989, presented alarming findings about the decline in amphibian populations. Currently, amphibians include the highest percentage of threatened species (>40%), as well as the highest number of data deficient species (>1500 species). The little we currently know about the occurrence of the chytrid fungus, which has already eradicated many amphibian species globally, is a grim example of how urgent it is to acquire further information.

Asian Common Toad. Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

Researchers just published the first comprehensive study on all known amphibian species of Pakistan in the open-access journal ZooKeys. In it, they report 21 species from the country, providing their identification key and photographic guide. However, as many of Pakistan’s potential amphibian habitats are difficult to access and study, especially the high-altitude northern and arid western mountains, it is highly likely that a lot of species are yet to be discovered.

Burrowing Frog (in amplexus). Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

In particular, the authors point out that habitats facing destruction, urbanization, pollution, unsustainable utilization and other human-caused threats need to be put on high priority, so that suitable conservation strategies can be devised. This way, amphibian populations would be better controlled with less financial, administrative, and human resources.

So far, amphibians have been excluded from all current legislative and policy decisions in the country. Likewise, they are not protected under any law. Hence, the legislation pertaining to rare and endemic species needs to be updated. Schedule III, which includes protected species, provincial and federal wildlife laws, and CITES appendices are in particular need of revision.

Common Skittering Frog. Photo by Herpetology Lab, Arid Agriculture University Rawalpindi

Currently, wildlife conservation projects in Pakistan mainly focus on carnivores, ungulates and birds. Therefore, the authors of the study propose adopting an inclusive wildlife conservation approach in Pakistan. This approach would advocate the integration of poorly documented taxa, such as amphibians, in wildlife conservation and management projects. It is by highlighting the significance of their existence and the intrinsic values of all wildlife species that local ecosystems can remain healthy in the long run.

“There is also a dire need to change social attitudes towards the appreciation and significance of amphibians in our society. This could be achieved by initiating community awareness, outreach and school classrooms, and through citizen science programs,” add the researchers.

Research article:
Rais M, Ahmed W, Sajjad A, Akram A, Saeed M, Hamid HN, Abid A (2021) Amphibian fauna of Pakistan with notes on future prospects of research and conservation. ZooKeys 1062: 157-175. https://doi.org/10.3897/zookeys.1062.66913

Shining like a diamond: a new species of diamond frog from northern Madagascar

Despite the active ongoing taxonomic progress on the Madagascar frogs, the amphibian inventory of this hyper-diverse island is still very far from being complete. More new species are constantly being discovered, often within already well-studied areas. So, in one of the relatively well-studied parks in northern Madagascar, a new species of diamond frog, Rhombophryne ellae, was found in 2017. Now, the discovery is published in the open-access journal Zoosystematics and Evolution.

Despite the active ongoing taxonomic progress on Madagascar’s frogs, the amphibian inventory of this hyper-diverse island is still very far from being complete. The known diversity of the diamond frog genus Rhombophryne in Madagascar has increased significantly (more than doubled!) over the last 10 years, but still there are several undescribed candidate species awaiting description. New species are constantly being discovered in Madagascar, often even within already well-studied areas. One such place is the Montagne d’Ambre National Park in northern Madagascar.

Montagne d’Ambre National Park is widely known for its endemic flora and fauna, waterfalls and crater lakes, and considered to be a relatively well-studied area. Yet, only two studies have been published so far on the reptiles and amphibians of the Park.

Rhombophryne ellae was captured just as Cyclone Ava began to make itself felt across Madagascar with high winds and heavy rain. The camp where Dr. Scherz and his team were based became flooded, with rivers running through the kitchen and sleeping area. Miserable weather for humans, but a time of increased activity for some of the more elusive amphibians of the forest.
Credit: Mark D. Scherz
License: CC-BY 4.0

Serving the pursuit of knowledge of the herpetofauna in the region, Germany-based herpetologist Dr. Mark D. Scherz (Bavarian State Collection of Zoology, Technical University of Braunschweig, University of Konstanz) published a description of a new diamond frog species: Rhombophryne ellae, in the open-access journal Zoosystematics and Evolution.

Rhomobphryne ellae
Credit: Mark D. Scherz
License: CC-BY 4.0

“As soon as I saw this frog, I knew it was a new species. The orange flash-markings on the legs and the large black spots on the hip made it immediately obvious to me. During my Master’s and PhD research, I studied this genus and described several species, and there are no described species with such orange legs, and only few species have these black markings on the hip. It’s rare that we find a frog and are immediately able to recognise that it is a new species without having to wait for the DNA sequence results to come back, so this was elating”,

shares Dr. Scherz.

The new species is most closely related to a poorly-known and still undescribed species from Tsaratanana in northern Madagascar, but is otherwise quite different from all other diamond frogs. With the orange colouration on its legs, Rhombophryne ellae joins the growing list of frogs that have red to orange flash-markings. The function of this striking colouration remains unknown, despite having evolved repeatedly in frogs, including numerous times in Madagascar’s narrow-mouthed frogs alone.

The new species, Rhombophryne ellae, is well camouflaged among the rainforest leaflitter
Credit: Mark D. Scherz
License: CC-BY 4.0

“The discovery of such a distinctive species within a comparatively well-studied park points towards the gaps in our knowledge of the amphibians of the tropics. It also highlights the role that bad weather, especially cyclones, can play in bringing otherwise hidden frogs out of hiding—Rhombophryne ellae was caught just as Cyclone Ava was moving in on Madagascar, and several other species my colleagues and I have recently described were also caught under similar cyclonic conditions”,

says Dr. Scherz.
Rhombophryne ellae is a small, probably semi-fossorial (sub-terranean-dwelling) species of diamond frog, at home amongst the leaf litter of Montagne d’Ambre National Park, north Madagascar
Credit: Mark D. Scherz
License: CC-BY 4.0

The species is known so far only from a single specimen, making it difficult to estimate its conservation status. Yet, based on the status of other, related frogs from the same area, it will probably be Red-listed as Near Threatened due to its presumably small range and micro-endemicity.

Original source:

Scherz MD (2020) Diamond frogs forever: a new species of Rhombophryne Boettger, 1880 (Microhylidae, Cophylinae) from Montagne d’Ambre National Park, northern Madagascar. Zoosystematics and Evolution 96(2): 313-323. https://doi.org/10.3897/zse.96.51372


‘Social distancing’ saves frogs: New approach to identify individual frogs noninvasively

aitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

A Beautiful stream frog (Amolops formosus) in a Himalayan torrent stream
Photo by Naitik Patel

Globally, 41% amphibian species are regarded as threatened with extinction. However, when it comes to the case of India, the majority of the species falls in the Data Deficient group, according to the criteria of the International Union for Conservation of Nature‘s (IUCN) Red List of Threatened Species.

This means that we hardly have any population data for Indian amphibians, which leads to a serious conservation bottleneck, especially when you are dealing with elusive herpiles. Therefore, there is the pressing priority to obtain demographic trends to prompt and support conservation actions for endemic and habitat-dependent species.

While demographics of natural populations is best estimated with the mark-recapture technique, used in animals, where individuals have distinct body markings, such as the stripes in a tiger, the dots in a whale shark and the fingerprints in a human. In the meantime, while frogs are well known for their individual-specific markings and colour patterns, this kind of technique has never been used in amphibians, even though they have long been recognised as some of the most vulnerable animals on Earth.

On the other hand, it is hardly possible to capture and mark individual frogs in the wild. So, Naitik Patel and Dr Abhijit Das of the Wildlife Institute of India came up with one of the very first non-invasive approaches to identify individual frogs using photos from their natural habitats, which are then processed with the animal recognition software HotSpotter. Their unique method is described in the open-access, peer-reviewed scientific journal Herpetozoa.

“Capturing each frog is not possible in the field, so to address this problem, we conducted a short study on Beautiful stream frogs (Amolops formosus), a species that, just like many other amphibians, has variable body markings amongst individuals. As this species inhabits the Himalayan torrent stream, which is difficult to access, we tried our best to photograph each frog from a distance to avoid any kind of physical contact,”

explains Naitik Patel, a PhD student at the Wildlife Institute of India.

A Beautiful stream frog (Amolops formosus)
Photo by Abhijit Das

Having concluded their study with a success rate of 94.3%, the research team is hopeful that their protocol could be effectively implemented in rapid population estimation for many endangered species of frogs.

“We conducted photographic documentation to capture the unique markings of each frog, and then compared them, using computer-assisted individual identification. With this method, the number of individuals can be counted to estimate the population structure. This study is exceptional, owing to the minimal disturbance it causes to the frogs. Such a technique has rarely been tried on amphibians and is a promising method to estimate their numbers. It can also be used in citizen science projects,”

comments senior scientist Dr Abhijit Das.

###

Original source:

Patel NG, Das A (2020) Shot the spots: A reliable field method for individual identification of Amolops formosus (Anura, Ranidae). Herpetozoa 33: 7-15. https://doi.org/10.3897/herpetozoa.33.e47279

New puddle frog species leaps into the spotlight from an unexplored mountain, Ethiopia

Two females and eggs of the newly described species (Phrynobatrachus bibita). Photo by S. Goutte and J. Reyes-Velasco.

A new species of puddle frog has just been discovered by NYU Abu Dhabi researchers at the unexplored and isolated Bibita Mountain in southwestern Ethiopia. The research team named the new species Phrynobatrachus bibita sp. nov., or Bibita Mountain dwarf puddle frog, inspired by its home.

In summer 2018, NYU Abu Dhabi Postdoctoral Associates Sandra Goutte and Jacobo Reyes-Velasco explored an isolated mountain in southwestern Ethiopia where some of the last primary forest of the country remains. Bibita Mountain was under the radars of the team for several years due to its isolation and because no other zoologist had ever explored it before.

“Untouched, isolated, and unexplored: it had all the elements to spike our interest,” says Dr. Reyes-Velasco, who initiated the exploration of the mountain. “We tried to reach Bibita in a previous expedition in 2016 without success. Last summer, we used a different route that brought us to higher elevation,” he added.

Female (Phrynobatrachus bibita) next to egg clutches. Photo by S. Goutte and J. Reyes-Velasco.

Their paper, published in ZooKeys journal, reports that the new, tiny frog (17 mm for males and 20 mm for females) is unique among Ethiopian puddle frogs. Among other morphological features, a slender body with long legs, elongated fingers and toes, and a golden coloration, set this frog apart from its closest relatives.

“When we looked at the frogs, it was obvious that we had found a new species, they look so different from any Ethiopian species we had ever seen before!” explains Dr. Goutte.

Back in NYU Abu Dhabi, the research team sequenced tissue samples from the new species and discovered that Phrynobatrachus bibita sp. nov. is genetically different from any frog species in the region.

“The discovery of such a genetically distinct species in only a couple of days in this mountain is the perfect demonstration of how important it is to assess the biodiversity of this type of places. The Bibita Mountain probably has many more unknown species that await our discovery; it is essential for biologists to discover them in order to protect them and their habitat properly,” explains NYU Abu Dhabi Program Head of Biology and the paper’s lead researcher Stéphane Boissinot, who has been working on Ethiopian frogs since 2010.

/Original text by New York University Abu Dhabi, UAE./

###

Original source:

Goutte S, Reyes-Velasco J, Boissinot S (2018) A new species of puddle frog from an unexplored mountain in southwestern Ethiopia (Anura, Phrynobatrachidae, Phrynobatrachus). ZooKeys 824: 53–70. https://doi.org/10.3897/zookeys.824.31570

Life in the fast flow: Tadpoles of new species rely on ‘suction cups’ to keep up

The frogs living in the rainforest of Sumatra also represent a new genus

Indonesia, a megadiverse country spanning over 17,000 islands located between Australia and mainland Asia, is home to more than 16% of the world’s known amphibian and reptile species, with almost half of the amphibians found nowhere else in the world. Unsurprisingly, biodiversity scientists have been feverishly discovering and describing fascinating new animals from the exotic island in recent years.

Sumatran forest

Such is the case of an international team from the University of Hamburg, Germany, University of Texas at Arlington, USA, University of Bern, Switzerland and Bandung Institute of Technology, Indonesia, who came across a curious tadpole while collecting amphibian larvae from fast-flowing streams as part of an arduous expedition in the remote forests on the island of Sumatra.

To the amazement of the scientists, it turned out that the tadpoles possess a peculiar cup-like structure on their bellies, in addition to the regular oral disk found in typical tadpoles. As a result, the team described two new species and a genus in the open access journal Zoosystematics and Evolution. A previously known, but misplaced in an unsuitable genus, frog was also added to the group, after it was proved that it takes advantage of the same modification.

This phenomenon where tadpoles display ‘belly suckers’ is known as gastromyzophory and, albeit not unheard of, is a rare adaptation that is only found in certain toads in the Americas and frogs in Asia,” explains lead author Umilaela Arifin.

The abdominal sucker, it is hypothesized, helps these tadpoles to exploit a very special niche – fast-flowing streams – where the water would otherwise be too turbulent and rapid to hang around. Gastromyzophorous species, however, rely on the suction provided by their modified bellies to secure an exclusive access to plentiful food, such as algae, while the less adapted are simply washed away.

When the scientists took a closer look at the peculiar tadpoles and their adult forms, using a powerful combination of molecular and morphological data, they realized that they had not only stumbled upon a rare amphibian trait, but had also discovered two brand new species of frogs in the process.

Sumaterana crassiovis

Moreover, the animals turned out so distinct in their evolutionary makeup, compared to all other frogs, that the scientists had to create a whole new genus to accommodate them. Formally named Sumaterana, the genus is to be commonly referred to as Sumatran Cascade Frogs.

We decided to call the new genus Sumaterana after Sumatra, to reflect the fact that these new species, with their rare evolutionary adaptation are endemic to Sumatra’s rainforests and, in a sense, are emblematic of the exceptional diversity of animals and plants on the island,” says co-author Dr. Utpal Smart. “Tragically, all of them are in peril today, given the current rate of deforestation.

The authors agree that much more taxonomic work is still needed to determine and describe Sumatra’s herpetofaunal diversity, some of which they fear, could be irreversibly lost well before biologists have the chance to discover it.

###

Original source:

Arifin U, Smart U, Hertwig ST, Smith EN, Iskandar DT, Haas A (2018) Molecular phylogenetic analysis of a taxonomically unstable ranid from Sumatra, Indonesia, reveals a new genus with gastromyzophorous tadpoles and two new species. Zoosystematics and Evolution 94(1): 163-193. https://doi.org/10.3897/zse.94.22120

New species of frog from the Neotropics carries its heart on its skin

In the Neotropics, there is a whole group of so-called glassfrogs that amaze with their transparent skin covering their bellies and showing their organs underneath. A recently discovered new species from Amazonian Ecuador, however, goes a step further to fully expose its heart thanks to the transparent skin stretching all over its chest as well as tummy.

The new amphibian is described by a team of scientists led by Dr. Juan M. Guayasamin, Universidad San Francisco de Quito, Ecuador, in the open access journal ZooKeys.

It can also be distinguished by the relatively large dark green spots at the back of its head and the foremost part of the body. Additionally, the species has a characteristic long call.

The new frog is named Hyalinobatrachium yaku, where the species name (yaku) translates to ‘water’ in the local language Kichwa. Water and, more specifically, slow-flowing streams are crucial for the reproduction of all known glassfrogs.

The reproductive behaviour is also quite unusual in this species. Males are often reported to call from the underside of leaves and look after the egg clutches.

Having identified individuals of the new species at three localities, the researchers note some behavioural differences between the populations. Two of them, spotted in the riverine vegetation of an intact forest in Kallana, have been calling from the underside of leaves a few metres above slow-flowing, relatively narrow and shallow streams. Another frog of the species has been observed in an area covered by secondary forests in the Ecuadorian village of Ahuano. Similarly, the amphibian was found on the underside of a leaf one metre above a slow-flowing, narrow and shallow stream.

oo_135330However, at the third locality – a disturbed secondary forest in San José de Payamino – the studied frogs have been perching on leaves of small shrubs, ferns, and grasses some 30 to 150 cm above the ground. Surprisingly, each of them has been at a distance greater than 30 metres from the nearest stream.

The researchers note that, given the geographic distance of approximately 110 km between the localities where the new species has been found, it is likely that the new species has a broader distribution, including areas in neighbouring Peru.

The uncertainty about its distributional range comes from a number of reasons. Firstly, the species’ tiny size of about 2 cm makes it tough to spot from underneath the leaves. Then, even if specimens of the species have been previously collected, they would be almost impossible to identify from museum collection, as many of the characteristic traits, such as the dark green marks, are getting lost after preservation. This is why the conservation status of the species has been listed as Data Deficient, according to the IUCN Red List criteria.

Nevertheless, the scientists identify the major threats to the species, including oil extraction in the region and the related water pollution, road development, habitat degradation and isolation.

“Glassfrogs presumably require continuous tracts of forest to interact with nearby populations, and roads potentially act as barriers to dispersal for transient individuals,” explain the authors.

###

Original source:

Guayasamin JM, Cisneros-Heredia DF, Maynard RJ, Lynch RL, Culebras J, Hamilton PS (2017) A marvelous new glassfrog (Centrolenidae, Hyalinobatrachium) from Amazonian Ecuador. ZooKeys 673: 1-20. https://doi.org/10.3897/zookeys.673.12108