Crested newts DNA research

This 30 June 2020 video from the Netherlands says about itself:

Some newts have a genetic malfunction that causes half of the eggs to cease. How is that possible? Manon de Visser is investigating this at Naturalis and the University of Leiden (Wielstra lab) and tells you everything about it in her first DNA talk!

Giant Japanese salamanders, video

This 26 May 2020 video says about itself:

The Startling Anatomical Features of this Ancient Salamander

Giant Japanese salamanders are a prehistoric species, dating back 200 million years. They’re highly adaptable, breathe through their skin, and boast not two, but three rows of teeth.

New newt species discovered in Vietnam

This 2016 video says about itself:

Himalayan crocodile salamanders

Who are they………

The animals in the salamander order look like a cross between a lizard and a frog. They have moist, smooth skin like frogs and long tails like lizards. The term “newt” is sometimes used for salamanders who spend most of each year living on land.

Himalayan salamander (Tylototriton verrucosus) are rare salamanders that exist till this day in the Namthing Lake of Shelpu Hills, a land with mesmerizing natural beauty covered with forests, fabulous views of Teesta River, deep gorges and g greenery all around. The major attractions of tourists include discovering the natural habitat of the endangered Himalayan salamander belonging to genus Tylototriton.

The salamanders of genus Tylototriton are found in India (West Bengal and Sikkim, Manipur, and Arunachal Pradesh) and eastern Nepal through the Kachin and Shan Hills of Myanmar to western Yunnan (Longchuan county and its vicinity), China and scattered mountains in northern Thailand. It has recently been recorded from Lai Chau and Lao Cai Provinces in northwestern Vietnam. It also occurs in Lao People’s Democratic Republic and Bhutan.

From ScienceDaily:

New to science newts from Vietnam

May 22, 2020

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.

Social distancing works for American newts, monkeys

This 18 April 2019 video says about itself:

Eastern newts mating in fresh water. Tetrodotoxin protects them

The Eastern Newt (Notophthalmus viridescens) is seen in this video reproducing in my freshwater pond. Amphibians need water to reproduce and these newts are actively mating just after a recent snow storm. They are undaunted by the cold and you can often see them and other species moving freely beneath thin ice.

It’s likely that the female in this video is anywhere from 12 to 15 years of age. Even though they are in my pond, they do cross land and can be found in streams, rivers and lakes where there is vegetation to provide them with cover.

The water temperature during these sequences was 56 degrees F. The red – Eft phase follows their tadpole phase and they appear mostly orange and can be found in wetland or damp woods much like the area shown. They stand out with their dazzling orange coloration, but are protected from predation due to the fact that their skin can emit tetrodotoxin which makes them taste terrible.

I will try to post updates and show the developing eggs as I find them. Always something interesting going on in spring.

This was filmed in the Northeastern United States in the State of Pennsylvania.

From the University of Tennessee Institute of Agriculture in the USA:

Transmission of the amphibian pathogen, Bsal

April 9, 2020

Summary: Using existing data from controlled experiments and computer simulations, researchers have found that host contact rates and habitat structure affect transmission rates of Bsal among eastern newts, a common salamander species found throughout eastern North America.

Researchers at the University of Tennessee Institute of Agriculture’s Amphibian Disease Laboratory are working to understand — and hopefully get ahead of — highly contagious pathogens affecting amphibians in Europe and Asia. One of the pathogens of interest is Batrachochytrium salamandrivorans, or Bsal.

Managed by Debra Miller and Matt Gray, professors in the Department of Forestry, Wildlife and Fisheries, the Amphibian Disease Laboratory is investigating disease management strategies for if, and possibly, when, Bsal makes its way to the United States through international animal trade or other means. Recent findings by Daniel Malagon, former undergraduate student working in the lab, show promising information for disease management of Bsal.

Using existing data from controlled experiments and computer simulations, Malagon found that host contact rates and habitat structure affect transmission rates of Bsal among eastern newts, a common salamander species found throughout eastern North America. Simply put, the higher the population density of the salamanders, the greater the rate of Bsal transmission. Malagon also found that adding habitat complexity, thereby separating the salamanders from each other, causes transmission rates to drop. These findings are similar to the results being observed when human populations follow the COVID-19 mitigation guidelines seen across the globe today.

Malagon’s academic advisor Matt Gray, who is also the chair of the North American Bsal Task Force, states, “Wildlife and humans pathogens are quite similar. In fact, Daniel’s results support the strategy of social distancing being used to mitigate the COVID-19 outbreaks. By reducing host density in newts or humans, contact rates, and therefore transmission, are reduced. Habitat structure also reduced contact rates of newts, so transmission is curtailed in more complex habitats. This may be analogous to COVID-19 environments. A person may be more likely to become infected in a homogenous movie theater compared to walking through a heterogeneous forest, even if density of people was the same.”

This research will support disease mitigation strategies for amphibians and could provide support for infectious disease recommendations for humans as well. “Our results suggest efficient pathogen spread in populations of highly susceptible salamander species, like the eastern newt. These populations will likely be negatively impacted if Bsal reaches North America. We hope our findings will help inform policy and management strategies to prevent the introduction of Bsal into North America,” added Malagon.

This research is in support of Gray and Miller’s National Science Foundation Project #181450, and the paper with these findings was recently published online by Nature Scientific Reports. Malagon, who is now a doctoral student at Clemson University, was supported in this research by the UT Knoxville College Scholars Program. Co-authors on the paper include Luis Melara of the Department of Mathematics, Shippensburg University; Olivia Prosper, formerly with the Department of Mathematics, University of Kentucky, and now with UT Knoxville; Suzanne Lenhart, Department of Mathematics, UT Knoxville; Jim Fordyce, Department of Ecology and Evolutionary Biology, UT Knoxville; and Davis Carter and Anna Peterson, Center for Wildlife Health, Department of Forestry, Wildlife and Fisheries, UT Institute of Agriculture.

Miller also holds an appointment in the Department of Biomedical and Diagnostic Sciences at the UT College of Veterinary Medicine and is currently serving as the interim director of the UT One Health Initiative. Announced in January, the UT One Health Initiative seeks fundamental answers to issues that address the inextricably linked health of humans, animals, plants and the environment as a whole.

Microorganisms living inside and on our body play a crucial role in both the maintenance of our health and the development of disease. Now researchers at UTSA have uncovered evidence about the importance of maintaining physical distance to minimize the spread of microbes among individuals. The scientists observed monkeys in the wild to understand what role genetics, diet, social groupings and distance in a social network play when it comes to the microbes found inside an animal’s gut: here.

Luminescent amphibians, new research

The ability to glow in a range of colors from green to yellow when exposed to blue light is common among amphibians like this green Pacman frog (Ceratophrys cranwelli), a new study reports. Photo J. Lamb, M. Davis

The ability to glow in a range of colors from green to yellow when exposed to blue light is common among amphibians like this green Pacman frog (Ceratophrys cranwelli), a new study reports.

By Erin Garcia de Jesus, February 27, 2020 at 11:00 am:

Glowing frogs and salamanders may be surprisingly common

Blue and UV light can make patterns invisible to humans in natural light appear on amphibians

Many animals — from marine species like fish to corals and land creatures like penguins and parrots — have a hidden skill: gleaming blue, green or red under certain kinds of light (SN: 11/17/17). But when it comes to amphibians, experts knew of only one salamander and three frogs that fluoresced — until now.

Jennifer Lamb and Matthew Davis, biologists at St. Cloud State University in Minnesota, shone blue or ultraviolet light on 32 species of amphibians, including salamanders, frogs and the wormlike caecilian, at varying life stages. To their surprise, all lit up, turning brilliant shades ranging from green to yellow, the researchers report February 27 in Scientific Reports.

The effect was strongest under blue light. Among all four-legged creatures, the ability to absorb higher-energy blue light and emit lower-energy green light had previously been documented only in marine turtles. The new finding suggests that biofluorescence is widespread among amphibians.

Different species glow in different patterns, the team found. Some, such as the eastern tiger salamander (Ambystoma tigrinum), reveal strips or blotches of color. In others, like the marbled salamander (A. opacum), bones and parts of their undersides light up.

Although the researchers didn’t test the mechanisms that amphibians use to glow, the animals may rely on fluorescent proteins or pigment-containing cells. Multiple mechanisms would hint that the ability evolved independently in different species, rather than being passed down by an ancient ancestor of modern amphibians.

Biofluorescence may help salamanders and frogs find one another in low light: Their eyes contain cells that are especially sensitive to green or blue light (SN: 4/3/17). Scientists could also harness the amphibians’ ability, using special lights to search for the animals during biodiversity surveys — particularly for those creatures that blend into their surroundings or hide in piles of leaves. Lamb already has hints that might work. As she’s prowled her family’s woods at night with blue light in hand, she’s spotted the telltale glow.

Olm salamanders in Slovenia, video

This 29 January 2020 video from Slovenia says about itself:

The caves beneath Predjama Castle are home to the remarkable olm salamanders. Their eerie pale skin and the fact that they possess both gills and lungs is why people call them ‘the human fish’.

Axolotl salamanders, genome research

This 2016 video says about itself:

Named for an Aztec God, This Species Is Critically Endangered | National Geographic

This unique salamander in Mexico is now fighting against extinction.

From Yale University in the USA:

Tiny salamander’s huge genome may harbor the secrets of regeneration

January 28, 2020

The type of salamander called axolotl, with its frilly gills and widely spaced eyes, looks like an alien and has other-worldly powers of regeneration. Lose a limb, part of the heart or even a large portion of its brain? No problem: They grow back.

“It regenerates almost anything after almost any injury that doesn’t kill it,” said Parker Flowers, postdoctoral associate in the lab of Craig Crews, the John C. Malone Professor of Molecular, Cellular, and Developmental Biology and professor of chemistry and pharmacology.

If scientists can find the genetic basis for the axolotl‘s ability to regenerate, they might be able to find ways to restore damaged tissue in humans. But they have been thwarted in the attempt by another peculiarity of the axolotl — it has the largest genome of any animal yet sequenced, 10 times larger than that of humans.

Now Flowers and colleagues have found an ingenious way to circumvent the animal’s complex genome to identify at least two genes involved in regeneration, they report Jan. 28 in the journal eLife.

The advent of new sequencing technologies and gene-editing technology has allowed researchers to craft a list of hundreds of gene candidates that could responsible for regeneration of limbs. However, the huge size of the axolotl genome populated by vast areas of repeated stretches of DNA has made it difficult to investigate the function of those genes.

Lucas Sanor, a former graduate student in the lab, and fellow co-first author Flowers used gene editing techniques in a multi-step process to essentially create markers that could track 25 genes suspected of being involved in limb regeneration. The method allowed them to identify two genes in the blastema — a mass of dividing cells that form at the site of a severed limb — that were also responsible for partial regeneration of the axolotl tail.

Flowers stressed that many more such genes probably exist. Since humans possess similar genes, the researchers say, scientists may one day discover how to activate them to help speed wound repair or regenerate tissue.

World’s biggest salamander, new discovery

This 2019 video is about giant salamanders.

From the Zoological Society of London in England:

New species of giant salamander is world’s biggest amphibian

74-year-old museum specimen

September 16, 2019

Using DNA from museum specimens collected in the early 20th century, researchers from ZSL (Zoological Society of London) and London’s Natural History Museum identified two new species of giant salamander — one of which they suspect is the world’s biggest amphibian.

Chinese giant salamanders, now classified as Critically Endangered, were once widespread throughout central, southern and eastern China. They have previously been considered a single species (Andrias davidianus). However, new analysis of 17 historical museum specimens and tissue samples from wild salamanders challenges this assumption.

The paper, published today (17.09.2019) in the journal Ecology and Evolution, found three distinct genetic lineages in salamanders from different river systems and mountain ranges across China. These lineages are sufficiently genetically different that they represent separate species: Andrias davidianus, Andrias sligoi, and a third species which has yet to be named.

One of the newly identified species, the South China giant salamander (Andrias sligoi), was first proposed in the 1920s based on an unusual salamander from southern China that lived at the time at London Zoo. The idea was then abandoned but has been confirmed by today’s study. The team used the same animal, now preserved as a specimen in the Natural History Museum after living for 20 years at the Zoo, to define the characteristics of the new species.

The other unnamed new species, from Huangshan (the Yellow Mountains), is still only known from tissue samples and has yet to be formally described.

The study’s lead author, Professor Samuel Turvey of ZSL’s Institute of Zoology, said: “Our analysis reveals that Chinese giant salamander species diverged between 3.1 and 2.4 million years ago. These dates correspond to a period of mountain formation in China as the Tibetan Plateau rose rapidly, which could have isolated giant salamander populations and led to the evolution of distinct species in different landscapes.

The decline in wild Chinese giant salamander numbers has been catastrophic, mainly due to recent overexploitation for food. We hope that this new understanding of their species diversity has arrived in time to support their successful conservation, but urgent measures are required to protect any viable giant salamander populations that might remain.

Salamanders are currently moved widely around China, for conservation translocation and to stock farms that cater for China’s luxury food market. Conservation plans must now be updated to recognise the existence of multiple giant salamander species, and movement of these animals should be prohibited to reduce the risk of disease transfer, competition, and genetic hybridisation.”

Chinese giant salamanders are the world’s biggest amphibians. The authors suggest that the newly discovered South China giant salamander — which can reach nearly two metres — is the largest of the three and is therefore the largest of the 8,000 or so amphibian species alive today.

ZSL works in China to protect giant salamanders in the wild and to raise their profile through our exhibit at London Zoo, where zookeepers welcomed four juveniles in September 2016. The salamanders were seized by Border Force after an attempt to illegally import them. One of the salamanders, named Professor Lew, has since moved into a state-of-the-art tank in the Zoo’s Reptile House, where visitors can come face-to-face with one of nature’s giants. The three others are currently being cared for behind the scenes. Keepers will eventually introduce another animal to Professor Lew as a mate and the remaining two may then move to a different zoo, as the adults are highly territorial and need to be housed in separate enclosures.

Melissa Marr, PHD researcher at the Natural History Museum London added: “These findings come at a time where urgent interventions are required to save Chinese giant salamanders in the wild. Our results indicate that tailored conservation measures should be put in place that preserve the genetic integrity of each distinct species. Our research also highlights the central role that The Natural History Museum’s collections can play in the conservation of Critically Endangered species.”

American salamanders and climate change

This video from the USA says about itself:

Plethodon montanus – courtship

Filmed and edited by James A. Organ in the 1960s. Animals are from the Whitetop/Mt. Rogers area, Grayson & Smyth counties, Virginia. See Organ (1958, Copeia, pp. 251-259) for a description of courtship in this population, then known as Plethodon jordani metcalfi. Film provided courtesy of Sylvia Organ.

From Clemson University in the USA:

How salamanders harness limb regeneration to buffer selves from climate change

September 10, 2019

Looking like a cross between a frog and a lizard, the gray cheek salamander has thin, smooth skin and no lungs. The amphibian breathes through its skin, and to survive it must keep its skin moist. As environmental conditions grow hotter or drier, scientists want to know whether and how these animals can acclimate.

Researchers from Clemson University’s College of Science have shown for the first time that these salamanders inhabiting the southern Appalachian Mountains use temperature rather than humidity as the best cue to anticipate changes in their environment. Significantly, the researchers observed that salamanders actually harness their unique ability to regenerate limbs to rapidly minimize the impact of hot temperatures.

The findings, which are described in the paper, “Thermal cues drive plasticity in desiccation resistance in montane salamanders with implications for climate change,” may have implications for other animals and even plants. The paper was published in Nature Communications on Sept. 9.

A major issue for these salamanders each day is the potentially fatal risk of drying out. Biological sciences associate professor Mike Sears and his research group have shown over the years that these animals tolerate dehydration by regulating their water loss through physiological changes. But the researchers didn’t fully understand how they did that until now.

“We’re the first to look on the molecular level at salamander physiology with respect to the environment,” said Sears, whose team conducted acclimation experiments and gene expression analysis. “We figured out from the genetic perspective how they do this.”

Lead author Eric Riddell, who earned his doctorate at Clemson in 2018 and is now a postdoctoral scholar at the Museum of Vertebrate Zoology at the University of California, Berkeley, collected about 150 salamanders from the mountains near Highlands, North Carolina, and brought them back to Sears’ Clemson lab, where he gave them a month to get used to their new environment.

He then divided the animals into four groups that would be exposed to different climate conditions they might experience currently or in the future. Because the animals are nocturnal, he and his undergraduate assistants moved the salamanders from a moist rehydration chamber each night into an activity chamber, where they walked for several hours in soil in the open air as they were exposed to different levels of temperature and humidity.

The researchers repeated this routine over several weeks, while also measuring how quickly the salamanders dried out and how much oxygen they consumed by calculating the vapor pressure deficit (VPD).

“We found that salamanders anticipate the risk of drying out by using temperature and not humidity,” said Riddell, noting that while humidity does play a role in the rate of dehydration, it’s not as reliable a cue for the animals.

Riddell also conducted gene analyses of tissue samples from the salamanders’ skin to understand what physiological changes were occurring at the cellular level that enabled the animals to hold water in their bodies rather than have it evaporate through their skin.

According to Riddell, as temperatures increased, the salamanders were able to break down and subsequently rebuild blood vessel networks in their skin. “This temperature-sensitive blood vessel regeneration suggests that salamanders regulate water loss through regression and regeneration of capillary beds in the skin,” Riddell said.

In the long term, Riddell said, this blood vessel development might help scientists understand a salamander’s unique ability to regenerate or regrow limbs, a model system for understanding regenerative medicine in humans.

“By just focusing on how they regrow this one single type of tissue, these blood vessels, researchers might be able to understand the process of regeneration better,” Riddell said.

This fall, Sears plans to explore what happens as salamanders become more tolerant of warmer temperatures. He and his students will conduct experiments at various elevations to determine the maximum temperature the animal will tolerate voluntarily. Since temperature changes with elevation, the amphibians will select an elevation with an acceptable temperature range.

“Ultimately we want to know how genetically adaptable animals are to changes in the future climate,” Sears explained. “One of the big questions in our field is whether animals can keep up with the rate of climate change through evolution. By leveraging these genomic tools as we did in this study, we can begin to answer such ecological questions.”

In addition to Riddell, other members of Sears’ team contributing to this study included Christina Wells, Clemson associate professor of biological sciences; Kelly Zamudio, Cornell University ecology and evolutionary biology professor; and Emma Roback, a Grinnell College undergraduate summer research intern.

This current study builds on Sears’ groundbreaking research, published in July 2018, which demonstrated the adaptability of seven species of mountain salamanders in adjusting to their changing environment.

Work was supported by grants from the National Science Foundation’s Doctoral Dissertation Improvement Grant (grant number 1601485) and Research Experience for Undergraduates (REU) programs. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Science Foundation. The Highlands Biological Station provided additional opportunities to collect data through its Grant-in-Aid program.