Further conservation measures are required to protect Vietnamese reptiles, such as the psychedelic rock gecko (Cnemaspis psychedelica), from habitat loss and overharvesting, concludes a new report, published in the open-access scientific journalNature Conservation.
Having identified areas of high reptile diversity and large numbers of endangered species, the study provides a list of the 50 most threatened species as a guide for further research and conservation action in Vietnam.
The study, based on the bachelor thesis of Lilli Stenger (University of Cologne, Germany), recommends IUCN CPSG’s One Plan Approach to Conservation measures, which, next to improved habitat conservation, also involves increasing the number of threatened species in breeding stations and zoos to maintain populations suitable for restocking.
The scientists identified 484 reptile species known to Vietnam, aiming to provide a baseline to authorities, conservationists, rescue centers, and zoos, so they can follow up with appropriate conservation measures for endangered species. They note that the number is likely to go up, as the country is regarded as a top biodiversity hotspot, and the rate of new reptile species discoveries remains high.
According to the IUCN Red List, 74 of the identified species are considered threatened with extinction, including 34 endemic species. For more than half of Vietnam’s endemic reptiles (85 of 159), the IUCN Red List status is either missing or outdated, and further research is imperative for these species, the researchers say.
Vietnam has a high level of reptile diversity and an outstanding number of endemic species. The species richness maps in the study revealed the Central Annamites in central Vietnam to harbor the highest endemic species diversity (32 species), which highlights it as a site of particular importance for reptile conservation. Alarmingly, a protected area analysis showed that 53 of the 159 endemic species (33.2%) including 17 threatened species, have been recorded exclusively from unprotected areas, such as the Psychedelic Rock Gecko.
In General, Vietnam is considered a country with high conservation priority due to habitat loss and overharvesting for trade, traditional medicine and food.
Globally, reptiles are considered a group of special conservation concern, as they play an important role in almost all ecosystems and often have relatively small distribution ranges, making them especially vulnerable to human threats.
Stenger L, Große Hovest A, Nguyen TQ, Pham CT, Rauhaus A, Le MD, Rödder D, Ziegler T (2023) Assessment of the threat status of reptile species from Vietnam – Implementation of the One Plan Approach to Conservation. Nature Conservation 53: 183 221. https://doi.org/10.3897/natureconservation.53.106923
A spectacular crocodile newt from the Central Highlands of Vietnam was just published in the international peer-reviewed open-access academic journal ZooKeys.
“It is an exceptional discovery as it is one of the most colourful species in the genus Tylototriton. This is also the first time that a crocodile newt species is recorded from the Central Highlands of Vietnam. Occurring at elevations from 1,800 to 2,300 m above sea level, this discovery sets an elevational record for the genus in the country, with former distribution ranges between 250 m and 1,740 m.”
says discoverer and first author of the study Trung My Phung.
The habitat of the new species is located approximately 370 air km away from the nearest Tylototriton population, which makes it an important discovery in terms of evolution and zoogeography.
The name “ngoclinhensis” refers to the type locality of the new species, Ngoc Linh Mountain. Restricted to evergreen montane forest, the Ngoc Linh Crocodile Newt is currently known only from the Ngoc Linh Nature Reserve, Kon Tum Province, in the Central Highlands of Vietnam. This is the eighth salamander taxon described from Vietnam, and is the thirty-ninth Tylototriton species officially recognized.
Crocodile newts, scientifically known as the genus Tylototriton,include nearly 40 species inhabiting montane forest areas throughout the Asian monsoon climate zone. Remarkably, 15 of these species have been described in the past five years, and there remain several unnamed taxa, which contain cryptic species that are morphologicallydifficult to distinguish.
Established in 1986, Ngoc Linh Nature Reserve is a key biodiversity area for rare species like the endangered Golden-winged Laughingthrush and the Truong Son Muntjac. The Ngoc Linh Crocodile Newt certainly will represent another flagship species of this protected area and its surroundings, say the researchers.
This recent discovery is another remarkable case, “demonstrating that the Central Highlands play a special role in Vietnamese amphibian diversification and evolution,” by the words of co-author Dr. Cuong The Pham from IEBR.
The Ngoc Linh Crocodile Newt belongs to the group of range-restricted, so-called micro-endemic species, which face the greatest risk of extinction because of their presumably small population size. Unfortunately, on top of its special zoogeographic situation and rarity, its particularly colorful appearance will likely make it highly attractive to illegal collectors.
“This has already been successfully implemented for another recently discovered, micro-endemic crocodile newt species from Vietnam, Tylototriton vietnamensis, of which already more than 350 individuals could have successfully been reproduced at the Cologne Zoo in Germany and also at the Melinh Station for Biodiversity in Vietnam, which is a promising example for IUCN’s Reverse the Red campaign and the idea of the conservation zoo”,
says Prof. Dr. Thomas Ziegler, Vietnam conservation team member and coordinator from Cologne Zoo, Germany.
Phung TM, Pham CT, Nguyen TQ, Ninh HT, Nguyen HQ, Bernardes M, Le ST, Ziegler T, Nguyen TT (2023) Southbound – the southernmost record of Tylototriton (Amphibia, Caudata, Salamandridae) from the Central Highlands of Vietnam represents a new species. ZooKeys 1168: 193-218. https://doi.org/10.3897/zookeys.1168.96091
Now, the first author of the study, PhD student Camila G. Meneses (University of Kansas), who was awarded at SAGE 2022 for her poster: “A New Species of Fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines” joins us for an interview, sharing some further insights into her research and recent publication.
Congratulations for your Best Poster award at SAGE 2022! Can you introduce the topic of your poster to our readers? How does it fit in the broader context of your research?
The poster is entitled “A New Species of Fringed Forest Gecko, Genus Luperosaurus (Squamata: Gekkonidae), from Sibuyan Island, Central Philippines”. We are currently describing a new species of one of the rarest endemic Philippine lizards which corresponds to the Sibuyan Island population in central Philippines.
It is a poorly understood Southeast Asian and Southwest Pacific genus Luperosaurus, known popularly as fringed geckos, wolf geckos, or flap-legged geckos, and is documented here for the first time.
In the context of my research, visualizing historical, dry land connections that were once shared among modern islands has been crucial for understanding the distribution of biodiversity in the Philippines, an archipelago in which sea level oscillations during the Pleistocene undoubtedly influenced the assembly of regionalized floras and faunas. Sibuyan Island, separated by deep-water channels from neighboring landmasses, harbors distinct communities of amphibians and reptiles, many of which are island endemics.
Happy to see your Annotated List of Species for amphibians and reptiles from the central Philippines, which just got published in the open-access journal Check List. Can you tell us a bit more about the biodiversity of the region and what made you and your co-authors choose it for your survey?
Centers of endemism in the Philippine archipelago coincide with the physiography of the greater Pleistocene Aggregate Islands Complexes (PAICs) of Luzon, Palawan, Negros-Panay (West Visayan islands), Mindoro, Mindanao, and the Sulu Archipelago during Pliocene and Pleistocene sea level regressions according to Inger (1954) and Voris ( 2000). However, until relatively recently, little attention was paid to fully inventorying smaller islands like those in central Romblon Province. The province is not only known for its beautiful landscapes but also the seascape.
Sibuyan was identified as a focal site for this study because of its unique complex ecosystem with notable geologic history that contributed to its high endemism—oceanic origin, geographic isolation, elevational relief, and relatively intact forests. In addition, Sibuyan Island presents biogeographically compelling questions relating to the colonization history of organisms that could only have arrived on Sibuyan by dispersing over water .
We also considered that a comprehensive characterization of the diversity and distribution of amphibians and reptiles of Mount Guiting-Guiting would be highly desirable on the part of the local government, specifically the Protected Management Board and the regional Department of Environment and Natural Resources (Region IV-B) for future management planning. The additional information and data will strengthen their existing conservation programs, ideally by engaging local communities, wildlife managers, ecotourists, and university researchers in Romblon Province.
What are some of the unique or unexpected challenges you encounter in doing biogeographic research? How do you tackle them?
This is my first co-led (with the late young mammalogist, James Alvarez) big expedition in the country. The most challenging aspects for us as students this time are getting funding to do ridge to reef sampling for each season (wet and dry season), the inaccessibility of the area, and the unexpected natural calamities when we are at the peak of the mountain.
Biodiversity conservation efforts often depend on cooperation with non-experts in the field and wider support within the local community. What is the most important message that you hope your research helps transmit to the general audience?
Our knowledge of the endemic species diversity in these islands is still incomplete. It is of crucial importance to continue long-term, repeated biodiversity survey efforts that utilize a multifaceted approach and integration of an independent data stream for the understanding of small islands’ species community composition.
We encourage the conservation of the island’s seascape and landscape (one of the well-known tourist spots in the country), and we highly encourage interested students in nearby universities to continue studying the richly biodiverse areas in the province.
Finding excitement in your work is one of the great gifts of doing what you are passionate about. What brings you the most excitement?
For me, gradually getting answers for your own questions and making new discoveries are exciting, but of course the outstanding scenery, journey, experiences, skill sets being developed, and the stories we come to create during each expedition are priceless.
Did you happen to encounter your favorite species during the field surveys in Mount Guiting-Guiting Natural Park?
Honestly, when I am studying the diversity of amphibians and reptiles of Mt. Guiting-Guiting Natural Park, I consider every species that we collect my favorite.
Each survey site brings new knowledge (i.e., new elevation site recording, morphological variation, new distribution records, varied habitat type preferences of secretive species, etc). There are observations that have not been documented for some species in previous studies (even going back over 50 years ago in Brown and Alcala field collection, or more recently in the 2012 study by Siler et al.). This is especially the case for secretive RIG island endemics of amphibian and reptile species.
However, there are three species I can definitely say are my favorites — Brachymeles dalawangdaliri, Pseudogekko isapa, and the undescribed species of Fringed Forest Gecko These are very rare and secretive species of Philippine endemic lizards that can be found, we assumed, on Romblon Island Group and nowhere else in the world. Hence, the new collections are, we can say, very highly significant.
The first two have very few museum specimens, but we were lucky enough to document and collect enough samples to redescribe both species in terms of their morphological variations and know their first ever phylogenetic placement in relation to its related congeners (see Meneses et al. 2020). The third one is our new discovery of the Fringed-forest Gecko.
“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems.
“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists at Gauhati University (Assam, India) before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems. Furthermore, some of those effects may take longer than others to identify and confirm.
This is how the research team of doctoral research fellow Somoyita Sur, Dr Prasanta Kumar Saikia and Dr Malabika Kakati Saikia decided to study roadkill along a 64-kilometre-long stretch of one of the major highways in India: the National Highway 715.
What makes the location a particularly intriguing choice is that it is where the highway passess between the Kaziranga National Park, a UNESCO World Heritage site in Assam and the North Karbi Anglong Wildlife Sanctuary, thus tempting animals to move to and from the floodplains of Kaziranga and the hilly terrain of the Sanctuary to escape the annual floods or – on a daily basis – in search for food and mating partners.
In the beginning, they looked into various groups, including mammals, birds, reptiles, and amphibians, before realising that the death toll amongst frogs, toads, snakes and lizards was indeed tremendous, yet overlooked. Their findings were recently published in the peer-reviewed scholarly journal Nature Conservation.
In conclusion, the scientists agree that roads and highways cannot be abandoned or prevented from construction and expansion, as they are crucial in connecting people and transporting goods and necessities.
Sur S, Saikia PK, Saikia MK (2022) Speed thrills but kills: A case study on seasonal variation in roadkill mortality on National highway 715 (new) in Kaziranga-Karbi Anglong Landscape, Assam, India. In: Santos S, Grilo C, Shilling F, Bhardwaj M, Papp CR (Eds) Linear Infrastructure Networks with Ecological Solutions. Nature Conservation 47: 87-104. https://doi.org/10.3897/natureconservation.47.73036
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.
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 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.
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).
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.
Follow Metabarcoding and Metagenomics (MBMG) journal on Twitter and Facebook.
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
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 byNavapol 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.
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.
Our observations on the quite small-bodied Asian kukri snakes in Thailand have documented a feeding behaviour which differs from anything ever described in snakes.
Normally, snakes would swallow their prey whole. However, this particular species: the Small-banded Kukri Snake (Oligodon fasciolatus), would instead use its enlarged posterior maxillary teeth to cut open the abdomen of large poisonous toads, then inserts its entire head into the cavity to pull out and eat the organs one by one, while the prey is still alive!
During those macabre attacks, we managed to capture on camera three times, the toads struggled vigorously to escape and avoid being eviscerated alive, but, on all occasions, this was in vain. The fights we saw lasted for up to a few hours, depending on the organs the snake would pull out first.
The toads observed belong to the quite common species called Asian Black-spotted Toad (Duttaphrynus melanostictus), which is known to secrete a potent toxin from their prominent parotid glands, located on the neck and all over the back. Could it be that the snakes have adopted this sophisticated and gory approach to avoid being poisoned?
In a fourth, and equally important, case, an adult kukri snake attacked a somewhat smaller individual of the same toad species. However, this time, the snake swallowed the entire toad. Why did the snake swallow the juvenile toad, we still don’t know. Perhaps smaller toads are less toxic than adults? Or, could it be that kukri snakes are indeed resistant to the Asian Black-spotted toad’s poison, yet the large size of the adult toads prevented the snakes from swallowing them in the three afore-mentioned cases?
At present, we cannot answer any of these questions, but we will continue to observe and report on these fascinating snakes in the hope that we will uncover further interesting aspects of their biology.
Perhaps you’d be pleased to know that kukri snakes are, thankfully, harmless to humans. However, I wouldn’t recommend being bitten by one of those. The thing is that they can inflict large wounds that bleed for hours, because of the anticoagulant agent these snakes inject into the victim’s bloodstream. Their teeth are designed to inflict lacerations rather than punctures, so your finger would feel as if cut apart! This secretion, produced by two glands, called Duvernoy’s glands and located behind the eyes of the snakes, are likely beneficial while the snakes spend hours extracting toad organs.
Bringsøe H, Suthanthangjai M, Suthanthangjai W, Nimnuam K (2020) Eviscerated alive: Novel and macabre feeding strategy in Oligodon fasciolatus (Günther, 1864) eating organs of Duttaphrynus melanostictus (Schneider, 1799) in Thailand. Herpetozoa 33: 157-163. https://doi.org/10.3897/herpetozoa.33.e57096
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.
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,”
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,”
A new study, published in the peer-reviewed open-access journal ZooKeys, describes two new to science species and one subspecies of crocodile newts from northern Vietnam. However, this manifestation of the incredible diversity of life hosted on our planet comes as an essential reminder of how fragile Earth’s biodiversity really is.
In time for the International Day for Biological Diversity 2020, the date (22 May) set by the United Nations to recognise biodiversity as “the pillars upon which we build civilizations”, a new study, published in the peer-reviewed open-access journal ZooKeys, describes two new to science species and one subspecies of crocodile newts from northern Vietnam. However, this manifestation of the incredible diversity of life hosted on our planet comes as an essential reminder of how fragile Earth’s biodiversity really is.
Until recently, the Black knobby newt (Tylototriton asperrimus) was known to be a common species inhabiting a large area stretching all the way from central and southern China to Vietnam. Much like most of the other members of the genus Tylototriton, colloquially referred to as crocodile newts or knobby newts, it has been increasingly popular amongst exotic pet owners and traditional Chinese medicine practitioners. Meanwhile, authorities would not show much concern about the long-term survival of the Black knobby newt, exactly because it was found at so many diverse localities. In fact, it is still regarded as Near Threatened, according to the International Union for Conservation of Nature‘s Red List.
However, over the past decade, the increasing amount of research conducted in the region revealed that there are, in fact, many previously unknown to science species, most of which would have been assumed to be yet another population of Black knobby newts. As a result, today, the crocodile newts represent the most species-rich genus within the whole family of salamanders and newts (Salamandridae).
Even though this might sound like great news for Earth’s biodiversity, unfortunately, it also means that each of those newly discovered species has a much narrower distributional range, making them particularly vulnerable to habitat loss and overcollection. In fact, the actual Black knobby newt turns out to only exist within a small area in China. Coupled with the high demand of crocodile newts for the traditional Chinese medicine markets and the exotic pet trade, this knowledge spells a worrying threat of extinction for the charming 12 to 15-centimetre amphibians.
In order to help with the answer of the question of exactly how many Vietnamese species are still being mistakenly called Black knobby newt, the German-Vietnamese research team of the Cologne Zoo (Germany), the universities of Hanoi (Vietnam), Cologne and Bonn (Germany), and the Vietnam Academy of Science and Technology analysed a combination of molecular and detailed morphological characters from specimens collected from northern Vietnam. Then, they compared them with the Black knobby newt specimen from China used to originally describe the species back in 1930.
Thus, the scientists identified two species (Tylototriton pasmansi and Tylototriton sparreboomi) and one subspecies (Tylototriton pasmansi obsti) previously unknown to science, bringing the total of crocodile newt taxa known from Vietnam to seven. According to the team, their discovery also confirms northern Vietnam to be one of the regions with the highest diversity of crocodile newts.
“The taxonomic separation of a single widespread species into multiple small-ranged taxa (…) has important implications for the conservation status of the original species,”
comment the researchers.
The newly discovered crocodile newts were named in honour of the specialist on salamander chytrid fungi and co-discoverer Prof. Dr. Frank Pasmans and, sadly, the recently deceased salamander enthusiasts and experts Prof. Fritz-Jurgen Obst and Prof. Dr. Max Sparreboom.
In light of their findings, the authors conclude that the current and “outdated” Near Threatened status of the Black knobby newt needs to be reassessed to reflect the continuous emergence of new species in recent years, as well as the “severe threats from international trade and habitat loss, which have taken place over the last decade.”
Meanwhile, thanks to the commitment to biodiversity conservation of Marta Bernardes, lead author of the study and a PhD Candidate at the University of Cologne under the supervision of senior author Prof Dr Thomas Ziegler, all crocodile newts were included in the list of internationally protected species by the Convention on International Trade in Endangered Species (CITES) last year.
Today, some of the threatened crocodile newt species from Vietnam are already kept at the Cologne Zoo as part of conservation breeding projects. Such is the case for the Ziegler’s crocodile newt (Tylototriton ziegleri), currently listed as Vulnerable on the IUCN Red List and the Vietnamese crocodile newt (Tylototriton vietnamensis), currently considered as Endangered. Fortunately, the latter has been successfully bred at Cologne Zoo and an offspring from Cologne was recently repatriated.
Bernardes M, Le MD, Nguyen TQ, Pham CT, Pham AV, Nguyen TT, Rödder D, Bonkowski M, Ziegler T (2020) Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam. ZooKeys 935: 121-164. https://doi.org/10.3897/zookeys.935.37138
The species was discovered by Thy Neang during Wild Earth Allies field surveys in June-July 2019 on an isolated mountain named Phnom Chi in the Prey Lang Wildlife Sanctuary when he encountered an unusual species of bent-toed gecko. “It was an extremely unexpected discovery. No one thought there were undescribed species in Prey Lang,” said Neang.
The geckos were found to belong to the C. irregularis species complex that includes at least 19 species distributed in south¬ern and central Vietnam, eastern Cambodia, and southern Laos. This is the first member of the complex to be found west of the Mekong River, demonstrating how biogeographic barriers can lead to speciation. Additionally, the geckos were unique in morphological characters and mitochondrial DNA, and distinct from C. ziegleri to which they are most closely related. Researchers have named the species Cyrtodactylus phnomchiensis after Phnom Chi mountain where it was found.
Bent-toed geckos of the genus Cyrtodactylus are one of the most species-diverse genera of gekkonid lizards, with 292 recognized species. Much of the diversity within Cyrtodactylus has been described only during the past decade and from mainland Southeast Asia, and many of these newly recognized species are thought to have extremely narrow geographic ranges. As such, Cyrtodactylus phnomchiensis is likely endemic to Phnom Chi, which consists of an isolated small mountain of rocky outcrops (peak of 652 m elevation) and a few associated smaller hills, altogether encompassing an area of approximately 4,464 hectares in Kampong Thom and Kratie Provinces within the Prey Lang Wildlife Sanctuary, Cambodia.
The forest habitat in Phnom Chi remains in relatively good condition, but small-scale illegal gold extraction around its base threatens the newly discovered species. A second species of lizard, the scincid Sphenomorphus preylangensis, was also recently described from Phnom Chi by a team of researchers including Neang. These new discoveries underscore the importance of Prey Lang Wildlife Sanctuary for biodiversity conservation and the critical need to strengthen its management.
Further, an assessment of C. phnomchiensis is urgently warranted by the IUCN Red List of Threatened Species (IUCN 2020) because of its small area of occupancy, status as relatively uncommon, and ongoing threats to its habitat.
“This exciting discovery adds another reptile species to science for Cambodia and the world. It also highlights the global importance of Cambodia’s biodiversity and illustrates the need for future exploration and biological research in Prey Lang,”
“When [Neang] first returned from fieldwork and told me that he had found a species in the C. irregularis group so far west of the Mekong River in Cambodia, I did not believe it. His discovery underscores how much unknown biodiversity remains out there in unexpected places. Clearly, Prey Lang Wildlife Sanctuary is important for biodiversity and deserves attention,”
said Neang’s co-author Stuart of the North Carolina Museum of Natural Sciences.