Tag: Squamata

Scientists discover bent-toed gecko species in Cambodia

Originally published by North Carolina Museum of Natural Sciences

A new species of bent-toed gecko (Cyrtodactylus phnomchiensis) has been described from Cambodia’s Prey Lang Wildlife Sanctuary by Wild Earth Allies Biologist Thy Neang in collaboration with North Carolina Museum of Natural Sciences‘ Herpetologist Bryan Stuart. This new species is described in ZooKeys.

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.

A new species of bent-toed gecko (*Cyrtodactylus phnomchiensis*) has been discovered in Cambodia’s Prey Lang Wildlife Sanctuary by Wild Earth Allies Biologist Thy Neang in collaboration with Bryan Stuart of the North Carolina Museum of Natural Sciences.
Photo by Thy Neang

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.

Habitat at Phnom Chi, the type locality of the newly described bent-toed gecko.
Photo by Thy Neang

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,”
said Neang.

“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.

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Original source:

Neang T, Henson A, Stuart BL (2020) A new species of Cyrtodactylus (Squamata, Gekkonidae) from Cambodia’s Prey Lang Wildlife Sanctuary. ZooKeys 926: 133-158. https://doi.org/10.3897/zookeys.926.48671

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For more information on Wild Earth Allies, please visit: http://www.wildearthallies.org.

For more information on the North Carolina Museum of Natural Sciences, please visit:http://www.naturalsciences.org.

Vibes before it bites: 10 types of defensive behaviour for the False Coral Snake

The False Coral Snake (Oxyrhopus rhombifer) may be capable of recognising various threat levels and demonstrates ten different defensive behaviours, seven of which are registered for the first time for the species. Scientists from the Federal University of Viçosa (Brazil) published their laboratory observation results based on a juvenile specimen in the open-access journal Neotropical Biology and Conservation.

In a recent paper in the open-access journal Neotropical Biology and Conservation, a group of Brazilian scientists from the Federal University of Viçosa (Brazil) published ten different defensive behaviours for the False Coral Snake (Oxyrhopus rhombifer), seven of which are registered for the first time for the species. One of these is reported for the first time for Brazilian snakes.

Evolution shaped anti-predator mechanisms in preys, which can be displayed either with avoidance or defensive behaviours. The current knowledge about such mechanisms are still scarce for many snake species, but it is constantly increasing over the last years. These data are helpful for better understanding of the species ecology, biology and evolution.

The False Coral Snake (O. rhombifer) is a terrestrial snake species with a colouration like the true coral snake . The species has a wide geographic distribution, occurring in Argentina, Paraguay, Uruguay, Bolivia and all Brazilian biomes. Among its previously known anti-predator mechanisms, this species has already shown cloacal discharge, body flattening, struggling, erratic movements and hiding the head.

However, these behaviors were only a small part of what this species is capable of doing to defend itself! In November 2017, a juvenile male captured in the Atlantic Forest of southeastern Brazil was observed under laboratory settings, where the scientists would simulate a predation attempt with an increasing threat level.

We released the snake on to the laboratory bench and let it notice our presence. The animal remained motionless at first, then performed a pronounced dorsoventral flattening of the anterior part of the body, raised its tail, adopted an S-shaped posture, raised the first third of the body and performed brief body vibrations. Then we approached the snake, which remained with the same posture and body vibrations. When we touched the animal (not handling), it remained with the S-shaped posture, keeping the first third of the body elevated and the dorsoventral flattening (however, less accentuated) and started to display erratic movements, false strikes and locomotor escape. When handled, the snake only struggled,
shares the lead scientist Mr. Clodoaldo Lopes de Assis.

Amongst ten recorded behaviour types only three were among those already registered for this species. Since defensive responses in snakes decrease as body size increases, juveniles exhibit a broader set of defensive behaviour than adults. Because of that, some types of behaviour described in this study might be explained either by physical constraints or stage of development of the individual.

Some types of behaviour resemble the ones of true coral snakes of the genus Micrurus, a group of extremely venomous snakes. Thus, this similarity may be linked with the mimicry hypothesis between these two groups, where harmless false coral snakes take advantage of their similar appearance to the true coral snakes to defend themselves.

Another type of anti-predation mechanism shown — body vibrations — is yet an unknown behaviour for Brazilian snakes and has been recorded for the first time. This type of behaviour is difficult to interpret, but could represent a defensive signal against non-visually orientated predators.

Finally, defensive strategies of the specimen differed according to the threat level imposed: starting from discouraging behaviour up to false bites, erratic movements and locomotor escape.

Some defensive types of behaviour displayed by the juvenile *Oxyrhopus rhombifer*
Credit: Mr. Clodoaldo Lopes de Assis
License: CC-BY 4.0

O. rhombifer may be capable of recognising different threat levels imposed by predators and adjusting its defensive behaviour accordingly,
highlights Mr. Clodoaldo Lopes de Assis.

Through such simple laboratory observations we can get a sense of how Brazilian snakes are yet poorly known regarding their natural history, where even common species like the false coral snake O. rhombifer can surprise us!
Mr. Clodoaldo Lopes de Assis adds in conclusion.

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Original source:
Lopes de Assis C, José Magalhães Guedes J, Miriam Gomes de Jesus L, Neves Feio R (2020) New defensive behaviour of the false coral snake Oxyrhopus rhombifer Duméril, Bibron & Duméril, 1854 (Serpentes, Dipsadidae) in south-eastern Brazil. Neotropical Biology and Conservation 15(1): 71-76. https://doi.org/10.3897/neotropical.15.e48564

Two new lizards with ‘heroic past’ discovered in the Chilean Andes

Two new species of lizards have been discovered in the Andean highlands of Southern Chile. Collected from areas of heroic past, both small reptiles were named after courageous tribal chiefs who have once fought against colonial Spaniards in the Arauco war. The study, conducted by a team of Chilean scientists, is published in the open access journal ZooKeys.

Jaime Troncoso-Palacios from Universidad de Chile and his team found both new species near a lake in a pre-Andean zone among deciduous vegetation. Following the examination of the collected specimens and further analysis of their mitochondrial DNA, performed by Dr. Alvaro A. Elorza from Universidad Andres Bello, Chile, the scientists concluded that they belong to species unknown to science.

One of the species, called Liolaemus janequeoae, or, Janequeo`s Lizard, is distinct for being smaller than its relatives, measuring a maximum of roughly 7 centimeters at length, as well as having no pattern on its back. Both features are quite striking for the group of lizards it belongs to. The only contrasting coloration for the species are several white scales appearing on the upper side in males. Otherwise, the species are predominantly light brown with pearly whitish down side of the body.

In the local Lonko tribe’s history, Janequeo was a prominent chief, who lost her partner during the Arauco war, after he was caught and tortured to death by the colonial Spaniards. She is said to have had a leading role in the Battle of Fort Puchunqui. Coincidentally, the new species was discovered where the war once took place, in the Araucanía Region.

The second new species, called Liolaemus leftrarui, or Leftraru`s Lizard, was collected from the same locality, hence it also received a heroic name honoured in the Arauco war. It is called after the most prominent Mapuche tribal chief. According to the stories, he was taken by the Kingdom of Chile’s Governor at the age of 11 to become his servant. There, however, he learned the military strategy of the Spanish, managed to escape and joined his people in the war. Later, not only did he kill his former master, but also won the most remarkable victories over the Spaniards.

The Leftraru`s Lizard is a large species of about 8 centimeters in length, characterised with absent precloacal pores, a common feature for its lizard group, save few. On the upper side of its body there are also unusual light blue dots. Overall, its colour is brown splashed with dark brown spots. Apart from the blue scattered scales on the back, there is also a bit of green on its head, limbs and tail. At the rear it becomes yellowish.

In conclusion, the authors note that the lizard fauna of Chile has been mistakenly assumed to be quite scarce up until recently. Yet, their latest discovery, along with several other new species, described in recent years, could be a clear sign that, “some populations under study could be described as new species in the future”.

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Original source:

Troncoso-Palacios J, Diaz HA, Puas GI, Riveros-Riffo E, Elorza AA (2016) Two new Liolaemus lizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae). ZooKeys 632: 121-146. https://doi.org/10.3897/zookeys.632.9528

The scaled king and his knight: 2 new giant bent-toed gecko species from New Guinea

The extremely complex geological history of New Guinea has allowed many of its animals and plants the chance to grow different enough to make a name for themselves. In the case of two newly described and unusually large gecko species – only a noble name would do. The two new species whose names respectively mean ‘knight’ and ‘king’ were discovered by a team led by Dr. Paul Oliver, The Australian National University and University of Melbourne, are described in the open-access journal ZooKeys.

Both new species belong to the world’s most diverse gecko genus Cyrtodactylus which comprises more than 200 species known to date. These reptiles are commonly called bent-toed or bow-fingered geckos due to their distinctive slender curved toes. They occur through Asia and Australia.

These 200 species vary greatly in size, build and colouration. However, one of the newly described species, called C. rex, meaning “king” in Latin, is the largest species in the genus, and among the biggest of all geckos in the world.

In general, the bent-toed geckos measure no more than 13 cm in length, yet the “gecko king” can grow up to 17 cm, with the females slightly bigger than the males. It is also characterised with upper body side covered in alternating regions of dark grey brown and medium brown. There are also variable in size and shape, but clearly defined dark grey-brown markings. All examined specimens are reported to have either four or five dark brown blotches or bands running down their original tails.

The second new species also bears a noble name – Cyrtodactyulus equestris, meaning ‘knight’ in Latin. It is also considered a giant among its relatives with its length of up to 14 cm for the females. Similarly to its larger relative, its head is large and wide, clearly distinct from the neck. Its upper side is coloured with alternating regions of light and medium brown. While in smaller individuals the patches are visibly defined by dark brown edging, such is missing in the larger ones, giving their pattern slightly faded appearance.

As a whole, the distribution of the two new geckos overlap, although the “gecko knight” is reported to prefer the relatively undisturbed hill or lower montane forests of northern New Guinea and its neighbour “the king” seems to stick to the surrounding lowlands.

While the larger size of the New Guinean bent-toed geckos seems to be an evolutionary trend, the role of potential factors such as competition, ecological diversification, isolation and dispersal remains quite a mystery.

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Original source:

Oliver PM, Richards SJ, Mumpuni, Rösler H (2016) The Knight and the King: two new species of giant bent-toed gecko (Cyrtodactylus, Gekkonidae, Squamata) from northern New Guinea, with comments on endemism in the North Papuan Mountains. ZooKeys 562: 105-130. doi: 10.3897/zookeys.562.6052

Single no more: First females of a Madagascan chameleon described with modern technologies

The first females of a scarcely known chameleon species from Northeast Madagascar have been described. Because of lack of genetic data, X-ray micro-computed tomography scans of the chameleon’s head were used for species assignment. Regrettably, the habitats of this and many other chameleon species are highly threatened by the ongoing deforestation in Madagascar. The study is published in the open-access journal Zoosystematics and Evolution.

Chameleons belong to the most popular animals of Madagascar and have been quite intensively studied in the past. However, many new species are still being discovered and described, and several species are only known by a single or a few specimens. Likewise, the chameleon species Calumma vatosoa from northeastern Madagascar was described in 2001 based on a single male. The identity of females of this species has been unclear until now.

Recently, the PhD student David Proetzel of the herpetology section of the Zoologische Staatssammlung Munchen (ZSM), Germany, found specimens of female chameleons in the collection of the Senckenberg Museum, Frankfurt am Main, Germany, that looked similar to Calumma vatosoa. The problem was, how to prove this? The specimens from Frankfurt were collected back in 1933 and therefore, the extraction of DNA for genetic analysis was not possible anymore.

Researchers of the ZSM have been using X-ray micro-computed tomography scans for a few years to study the internal morphology of organisms in a non-invasive way.

“With the help of Micro-CT you can investigate even the skeleton of very valuable samples like holotypes without destroying them,” explains David Proetzel.

“In chameleons the morphology of the skeleton, especially the skull, contains important characteristics that distinguish different species,” explains the researcher. “Here, the comparison of the skulls of the male and the female showed that they belong to the same chameleon species. With the help of modern technology we could describe females of Calumma vatosoa for the first time, and add another distribution locality of this species.”

“The habitats of many chameleon species, and not only, are highly threatened by the ongoing deforestation in Madagascar and we need rapidly to expand our knowledge about the biodiversity, so that suitable conservation measures can be taken,” he stresses.

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Original source:

Proetzel D, Ruthensteiner B, Glaw F (2016) No longer single! Description of female Calumma vatosoa (Squamata, Chamaeleonidae) including a review of the species and its systematic position. Zoosystematics and Evolution, 92 (1): 13-21. doi: 10.3897/zse.92.6464