Tag: frogs

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.

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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.

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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.

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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

Twenty-five frogs added to the amphibian fauna of Mount Oku, Cameroon

While amphibians all over the world are undergoing a continuous decline, their status in certain regions, such as Central Africa, remains unknown due to incomplete information. New paper, published by two scientists in the open access journal ZooKeys, addresses the knowledge gap by providing an updated list of already 50 amphibian species living on Mount Oku, Cameroon.

Scientists Dr Thomas M. Doherty-Bone, Royal Zoological Society of Scotland, and Dr Václav Gvoždík, affiliated with both the Czech Academy of Sciences and the National Museum in Prague, have spent more than 10 years studying the Cameroonian mountain. As a result of their thorough surveys, literature review, and re-examination of museum specimens, there are now 50 species known from the locality, which doubles previous numbers. In their newly published checklist the researchers have listed 49 species of frogs and toads, as well as one caecilian species – a limbless, snake-like amphibian.

However, the number of threatened species seems to increase quite proportionally. Many of the newly recorded frogs, for instance, appear to be extremely endangered, yet they have not been assessed by the International Union for Conservation of Nature (IUCN). Therefore, the authors have used the IUCN criteria to propose conservation assessments for them. If the suggested statuses are approved, together with the updated declines of previously abundant in the area species, the proportion of the threatened would rise to nearly half (48%) of the Mount Oku’s entire amphibian fauna. Meanwhile, it is 42% of amphibians at risk of extinction globally.

In their study, the scientists also review the research and conservation undertaken at the mountain so far, including the work they have initiated themselves. Although Mount Oku’s forest turned out to be the best managed among the rest in the region, threats such as forest loss, encroachment and degradation are still largely present and increasing. Additional threats, including use of agrochemicals, climate change and diseases, have also been identified. However, conservation actions for the amphibians of Mount Oku are on the rise, considering both the population and the ecosystem-level perspectives.

“Our paper provides a foundation for continuously improving amphibian conservation at Mount Oku, as well as other mountains in Cameroon,” conclude the authors.

Original source:

Doherty-Bone TM, Gvoždík V (2017) The Amphibians of Mount Oku, Cameroon: an updated species inventory and conservation review. ZooKeys 643: 19-139. https://doi.org/10.3897/zookeys.643.9422