Tag: anurans

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

‘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

Eleven new species of rain frogs discovered in the tropical Andes

One of the newly described species: *Pristimantis chomskyi*.
Its name honors Noam Chomsky, a renowned linguist from ASU.
Image by David Velalcázar, BIOWEB-PUCE.

Eleven new to science species of rain frogs are described by two scientists from the Museum of Zoology of the Pontifical Catholic University of Ecuador in the open-access journal ZooKeys. Discovered in the Ecuadorian Andes, the species are characterized in detail on the basis of genetic, morphological, bioacoustic, and ecological features.

On the one hand, the publication is remarkable because of the large number of new species of frogs. Regarding vertebrate animals, most studies only list between one and five new to science species, because of the difficulty of their collection and the copious amount of work involved in the description of each. To put it into perspective, the last time a single article dealt with a similar number of newly discovered frogs from the western hemisphere was in 2007, when Spanish scientist Ignacio de la Riva described twelve species from Bolivia.

The Rain frogs comprise a unique group lacking a tadpole stage of development. Their eggs are laid on land and hatch as tiny froglets.
Image by BIOWEB-PUCE.

On the other hand, the new paper by Nadia Paez and Dr Santiago Ron is astounding due to the fact that it comes as part of the undergraduate thesis of Nadia Paez, a former Biology student at the Pontifical Catholic University, where she was supervised by Professor Santiago Ron. Normally, such a publication would be the result of the efforts of a large team of senior scientists. Currently, Nadia Paez is a PhD student in the Department of Zoology at the University of British Columbia in Canada.

Unfortunately, amongst the findings of concern is that most of the newly described frog species are listed as either Data Deficient or Threatened with extinction, according to the criteria of the International Union for Conservation of Nature (IUCN). All of the studied amphibians appear to have very restricted geographic ranges, spanning less than 2,500 km2. To make matters worse, their habitats are being destroyed by human activities, especially cattle raising, agriculture, and mining.

Amongst the newly described species, there is the peculiar Multicolored Rain Frog, where the name refers to its outstanding color variation. Individuals vary from bright yellow to dark brown. Initially, the studied specimens were assumed to belong to at least two separate species. However, genetic data demonstrated that they represented a single, even if highly variable, species.

Variations of the Multicolored Rain Frog. Its name makes reference to the outstandingly varied colorations within the species.
Image by BIOWEB-PUCE.

The rest of the previously unknown frogs were either named after scientists, who have made significant contributions in their fields, or given the names of the places they were discovered, in order to highlight places of conservation priority.

###

Original source:

Paez NB, Ron SR (2019) Systematics of Huicundomantis, a new subgenus of Pristimantis (Anura, Strabomantidae) with extraordinary cryptic diversity and eleven new species. ZooKeys868: 1-112. https://doi.org/10.3897/zookeys.868.26766.

Extraordinary treefrog discovered in the Andes of Ecuador

*An adult of the newly described species, Hyloscirtus hillisi. Photo by Gustavo Pazmiño, BIOWEB Ecuador.*

A new treefrog species was discovered during a two-week expedition to a remote tabletop mountain at Cordillera del Cóndor, a largely unexplored range in the eastern Andes.

“To reach the tabletop, we walked two days along a steep terrain. Then, between sweat and exhaustion, we arrived to the tabletop where we found a dwarf forest. The rivers had blackwater and the frogs were sitting along them, on branches of brown shrubs similar in color to the frogs’ own. The frogs were difficult to find, because they blended with their background,” Alex Achig, one of the field biologists who discovered the new species comments on the hardships of the expedition.

Curiously, the frog has an extraordinary, enlarged claw-like structure located at the base of the thumb. Its function is unknown, but it could be that it is used either as a defence against predators or as a weapon in fights between competing males.

Having conducted analyses of genetic and morphologic data, scientists Santiago R. Ron, Marcel Caminer, Andrea Varela, and Diego Almeida from the Catholic University of Ecuador concluded that the frog represented a previously unknown species. It was recently described in the open-access journal ZooKeys.

*Unlike other frogs, the new species has a claw at the base of the thumb. Photo by Gustavo Pazmiño, BIOWEB Ecuador.*

The species name, Hyloscirtus hillisi, honors Dr. David Hillis, a member of the National Academy of Sciences of the United States of America, who discovered three closely related frog species in the same genus in the 1980s, while conducting a series of field trips to the Andes of southern Ecuador. Throughout his career, Dr. Hillis has made significant contributions to the knowledge of Andean amphibians and reptiles.

Despite being newly described, Hyloscirtus hillisi is already at risk of extinction. It has a small distribution range near a large-scale mining operation carried out by a Chinese company. Habitat destruction in the region has been recently documented by the NGO Amazon Conservation.

###

Original source:

Ron SR, Caminer MA, Varela-Jaramillo A, Almeida-Reinoso D (2018) A new treefrog from Cordillera del Cóndor with comments on the biogeographic affinity between Cordillera del Cóndor and the Guianan Tepuis (Anura, Hylidae, Hyloscirtus). ZooKeys 809: 97-124. https://doi.org/10.3897/zookeys.809.25207

*A metamorph of the new species, Hyloscirtus hillisi. Photo by Darwin Núñez, BIOWEB Ecuador.*

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.

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.

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.

However, 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

New frog from the Peruvian Andes is the first amphibian named after Sir David Attenborough

While there are already a number of species named after famous British broadcaster and naturalist Sir David Attenborough, including mammals, reptiles, invertebrates and plants, both extinct and extant, not until now has the host of the BBC Natural History’s Life series been honoured with an amphibian.

A new fleshbelly frog, recently discovered in the Peruvian Andes, is formally described as Pristimantis attenboroughi, while commonly it is to be referred to as the Attenborough’s Rubber Frog. The new species is published in the open-access journal ZooKeys.

Scientists Dr. Edgar Lehr, Illinois Wesleyan University, and Dr. Rudolf von May, University of Michigan, spent two years (2012-2014) surveying montane forests in central Peru, in order to document the local amphibians and reptiles, and evaluate their conservation statuses. Their efforts have been rewarded with several new species of frogs and a new spectacled lizard.

Each of these discoveries, including the Attenborough’s Rubber Frog, prove how beneficial it is to take into account both morphological and the genetic data, while looking for species new to science. For example, the authors report that when they spotted the P. attenboroughi frog for the first time, both of them were sure that they had found a species of another genus.

The Attenborough’s rubber frog is known to inhabit several localities across the Pui Pui Protected Forest, a nature reserve located at elevations between 3400 and 3936 m a.s.l. in central Peru. The adult males reach size of 14.6-19.2 mm in length, while the females are larger measuring between 19.2 and 23.0 mm. Their ground colour ranges from pale to dark gray, or reddish brown to brownish olive with dark gray scattered flecks. Meanwhile, the juveniles are paler (yellowish to reddish brown) with contrasting dark brown flecks and distinct stripes.

Due to the amphibian being known from fewer than ten localities, spread across less than 20,000 km2, the species should be deemed either Vulnerable or Endangered, according to the IUCN Red List Categories and Criteria. However, the authors suggest that the Attenborough’s Rubber frog should be listed as Near Threatened instead, since the Piu Piu forest is formally protected and still largely unknown, so it is likely that there are more additional populations of the new species. On the other hand, factors such as fungal infections, climate change, pollution, and man-made fires continue to be threats for many Andean amphibians even inside protected areas.

“We dedicate this species to Sir David Frederick Attenborough in honor for his educational documentaries on wildlife, especially on amphibians (e.g., Life in Cold Blood, Fabulous Frogs), and for raising awareness about the importance of wildlife conservation,” explain the authors.

In the present study, the scientists note that there are more terrestrial-breeding frogs from the surveyed montane forests that will be described in the near future.

Among the numerous namesakes of Sir David Attenborough to date, there are a rare genus of beautiful flowering plants, a rare butterfly species, commonly known as the Attenborough’s black-eyed satyr, a flightless weevil species, as well as a number of extinct species.

###

Original source:

Lehr E, von May R (2017) A new species of terrestrial-breeding frog (Amphibia, Craugastoridae, Pristimantis) from high elevations of the Pui Pui Protected Forest in central Peru. ZooKeys 660: 17-42. https://doi.org/10.3897/zookeys.660.11394

Exceptional reproductive biology in extremely restricted critically endangered Nimba toad

The critically endangered Nimba toad is long known for its exceptional reproductive biology. The females of this unique species give live birth to fully developed juveniles, having for nine months continuously provided nutrition to the foetuses in the womb (matrotrophy). While live birth (viviparity) among frogs and toads is rather an exception than a common characteristic, matrotrophy, in place of alternatives such as the foetus being fed with yolk, unfertilized eggs, or smaller siblings, is what makes the Nimba toad one of a kind.

However, more than 40 years of research had not been comprehensively, accessibly and completely summarised. The gap has recently been filled with a new paper, published in the open access journal Zoosystematics and Evolution by German scientists Drs. Laura Sandberger-Loua and Mark-Oliver Rödel, both affiliated with Museum für Naturkunde, Berlin, and Dr. Hendrik Müller, Friedrich-Schiller-Universität Jena.

Studying the phenomenon, the scientists went through the literature published over four decades to gather the scattered details. They have also discussed the relationship between the toad’s reproductive biology and its specific habitat of merely 4 km² of high altitude grasslands located at a minimum of 1,200 m in the Nimba mountains, West Africa.

The climate of the area is characterised by a rainy season lasting from April to October and a dry season from November to February/March. These seasons are found to determine the activity of the Nimba toads. The amphibians are only active during the rainy season, when they give birth to their young, mate, and then find shelter underground, where they stay dormant during the dry season.

Visibly females can be distinguished from male Nimba toads by their differing cloaca and often larger size, compared to the males. Also, males show darker backs and, during most of their adult life, nuptial pads on their thumbs, which look like spiky swellings. This secondary sex characteristic, in its seasonal change linked to spermatogenesis, is used by the males to grasp tightly the female while mating.

In this species mating occurs without a copulatory organ. Instead, the sperm is transferred through connection of the cloacae, where the male’s swells and encloses the female’s cloaca. Furthermore, Nimba toads have a unique behavioural repertoire. Males crouch on their front legs and as soon as the female moves, follow her and grab her tightly in the groin. Due to the spiky nuptial pads, the males often injure their partner.

Giving birth in Nimba toads may take over two days, depending on the number of offspring, which can be up to 12 in older females – far fewer than the hundreds of eggs in most toad species. While giving birth, a female assumes a unique “birthing posture” to compensate for the lack of enough muscle power to expel juveniles. By the time the juveniles are ready to be born, they have already taken up nearly all the space in their mother’s body. The scientists conclude that the offspring play an active role in the process, as a juvenile toad’s death midway in the oviduct leads to the mother dying of sepsis.

Living exclusively in the Nimba mountains, and being listed as Critically Endangered, according to the IUCN, the studied toad is only one of the species restricted to the high altitude grasslands, which led to the declaration of the Nimba mountains as a World Heritage Site by UNESCO. Separated from other mountains, its inhabitants are isolated from external contacts, thus presumably leading to their evolutionary separation from related species. Furthermore, the toad’s unique reproductive biology is probably the result of this isolation, argue the authors.

In conclusion, the authors suggest that “it is likely that the harsh unpredictable environment and scarcity of open water promoted viviparity in Nimba toads, or supported the survival of this unique reproductive mode in these special and isolated conditions. Considering their complex life cycle, in which reproductive and seasonal cycles are tightly linked, understanding and protecting the Nimba toad’s threatened environment is of utmost importance.”

###

Original source:

Sandberger-Loua L, Müller H, Rödel M-O (2017) A review of the reproductive biology of the only known matrotrophic viviparous anuran, the West African Nimba toad, Nimbaphrynoides occidentalis. Zoosystematics and Evolution 93(1): 105-133. https://doi.org/10.3897/zse.93.10489