This November 2019 video from Canada is called Blue-spotted salamander: from egg to adult.
This November 2019 video from Canada is called Blue-spotted salamander: from egg to adult.
This June 2014 video shows a small young natterjack toad being freed again in the wild in the Netherlands.
After 28 September 2019 on Terschelling island came 30 September for us.
A small young natterjack toad had managed to slip under our front door. We returned it to the sand dunes area.
In the gardens on both sides of the Parnassiaweg road in West-Terschelling village, robins sang, replying to each other.
In one of these gardens, sulphur tuft fungi.
This September 2015 video from Britain is about sulphur tuft mushrooms.
This 25 October 2019 Russian video says about itself (translated):
Found in Komi republic: the remains of the oldest ancestor of all terrestrial vertebrates
In Komi, the remains of one of the first tetrapods were discovered – an animal, thanks to which vertebrates were able to go on land, becoming the ancestors of amphibians, reptiles, birds and mammals. The Russian tetrapod was called Parmastega aelidae. Its age is 372 million years. Parmastega bones were discovered in the vicinity of the city of Ukhta.
From the University of Lincoln in England:
Massive fangs and a death crush: How a 370 million year old tetrapod hunted and killed
October 24, 2019
The habits of a needle-toothed tetrapod which lived more than 370 million years ago have filled in a piece of the evolutionary puzzle thanks to new research.
An international team of palaeontologists pieced together the fossilised skeletons of a new species of tetrapod called Parmastega aelidae and found it had a skull which resembled a crocodile — a unique feature among the earliest tetrapods — with eyes situated well above the top of its head, suggesting it was capable of “keeping an eye” on unsuspecting prey while swimming close to the surface of a tropical lagoon.
The unusual combination of anatomical features has cast new light on how one of [our] most distant ancestors hunted and its life-style. Researchers believe it would have used its slender needle-like teeth and elastic jaw to snatch prey before crushing it to death with massive fangs protruding from its palate.
The team also found that part of its shoulder girdle consisted of cartilage, and its vertebral column and paired limbs could also be made of cartilage, indicating it probably spent most or all its time in water. The concentration of the fossil remains also suggests that it may have lived in large groups.
Tetrapods are represented today by amphibians, reptiles, birds and mammals, and Parmastega predates the former earliest records of complete or almost complete tetrapod skeletons by nearly 12 million years.
The new study was led by the Ural Branch of the Russian Academy of Science, in partnership with the Universities of Lincoln and Cambridge in the UK, the University of Latvia, and the University of Uppsala in Sweden. It was funded by the National Geographic Society, the Latvian Council of Science, and the Knut and Alice Wallenberg Foundation.
Professor Per Ahlberg from the University of Uppsala in Sweden, explained that a clue to the lifestyle of Parmastega was provided by its sensory canals, used to detect vibrations in the water, which Parmastega inherited from its fish ancestors.
“These canals are well developed on the lower jaw, the snout and the sides of the face, but they die out on top of the head behind the eyes,” he said. “This probably means that it spent a lot of time hanging around at the surface of the water, with the top of the head just awash and the eyes protruding into the air.
“We believe there may have been large arthropods such as millipedes or ‘sea scorpions‘ to catch at the water’s edge. The slender, elastic lower jaw certainly looks well-suited to scooping prey off the ground, its needle-like teeth contrasting with the robust fangs of the upper jaw that would have been driven into the prey by the body weight of Parmastega.
“These fossils give us the earliest detailed glimpse of a tetrapod: an aquatic, surface-skimming predator, just over a metre in length, living in a lagoon on a tropical coastal plain.”
Dr Marcello Ruta from Lincoln’s School of Life Sciences added: “The evolution of tetrapods is one of the most important events in the history of backboned animals, and ultimately led to the appearance of our own species. Early in their history, tetrapods evolved many changes in their feeding strategies, movement abilities, and sensory perception, but many of these are still shrouded in mystery.
“Like all fossil organisms, Parmastega occupies a special and unique place in the tree of life. Our study welcomes a new, very early member of that tree which shows considerable anatomical, functional and ecological experimentation.
“These new findings demonstrate that the sequence of evolutionary changes that occurred during the transition from fish-like creatures to tetrapods were much less linear than previously thought. This helps us to amend or challenge previous evolutionary scenarios and give new insights into the life and environments of our most distant forerunners. Findings like those of Parmastega can help us grasp the complex patterns and processes that have shaped life’s diversity for hundreds of millions of years.”
This 21 October 2019 video says about itself:
It is well known that some harmless animals mimic dangerous animals to ward off predators.
Such posing is called Batesian mimicry. But the Congolese giant toad takes Batesian mimicry to a new level. According to a paper in the Journal of Natural History, the toad not only transform into a very good copy of a Gaboon Viper. It also tries to mimic the hiss the deadly snake make before an attack. The toad also postures so that its front limbs aren’t visible — making it look more snake-like. The Congolese giant toad are found in locations inhabited by the Gaboon viper. The Gaboon viper has the longest fangs and carries the most venom.
Toad disguises itself as deadly viper to avoid attack
Decades of fieldwork uncover hissing and strike-warning impersonations by toad
October 21, 2019
The first study of a toad mimicking a venomous snake reveals that it likely imitates one of Africa’s largest vipers in both appearance and behaviour, according to results published in the Journal of Natural History.
The Congolese giant toad, a triple cheeseburger-sized prize for any predator, may use its ability to mimic the highly venomous Gaboon viper to escape being eaten. The viper has the longest snake fangs in the world and produces more venom than any other snake.
“Our study is based on ten years of fieldwork and on direct observation by researchers lucky enough to see the toad’s behaviour first-hand. We’re convinced that this is an example of Batesian mimicry, where a harmless species avoids predators by pretending to be a dangerous or toxic one,” says Dr Eli Greenbaum from the University of Texas at El Paso. “To fully test our hypothesis, we’d have to demonstrate that predators are successfully duped, but this would be very difficult in the wild, where the toads are only encountered rarely. However, based on multiple sources of evidence provided in our study, we are confident that our mimicry hypothesis is well-supported.”
The researchers made comparisons between the appearance of the toad, found in central African rainforests, and the viper, which is more widespread in central, eastern and southern Africa. Using live wild-caught and captive specimens, as well as preserved museum ones, they found that the colour pattern and shape of the toad’s body is similar to that of the viper’s head. Most striking are two dark brown spots and a dark brown stripe that extends down the toad’s back, the triangular shape of the body, a sharp demarcation between the tan back and dark brown flanks, and the species’ extraordinarily smooth skin for a toad. Because the Gaboon viper is capable of causing deadly bites, would-be predators likely avoid the similar-looking toads to ensure they don’t make a lethal mistake.
Some mimics are exclusively visual, but for the Congolese giant toad, getting the look right is only part of the impersonation. If a Gaboon viper feels threatened, it will often incline its head and emit a long, loud warning hiss before it actually makes a strike. Similarly, Congolese herpetologist Chifundera Kusamba observed the toad emitting a hissing noise resembling the sound of air being slowly released from a balloon. Over a century ago, American biologist James Chapin observed a bow display by the toad, where the front limbs no longer prop up the viperine-shaped body, which looks similar to the cocked head of a snake threatening to strike.
The final part of the impersonation is getting the location right. Even the best impression will only work if predators of the harmless species are familiar with the venomous one. The researchers compared the geographical range of the toad and viper in the Democratic Republic of Congo (DRC) and found that the Congolese giant toad does not seem to occur in areas where the Gaboon viper is absent. The researchers identified 11 locations in the eastern rainforests where the range of both species overlaps.
Based on speciation dating estimates from genetic data, the Congolese giant toad and Gaboon viper first evolved at about the same time in the early Pliocene about 4-5 million years ago. Considered with their similar appearance, behaviour, and overlapping geographic distribution, the toads and vipers likely coevolved together, further supporting the mimicry hypothesis.
“Given the relatively large size and therefore calorific value of this toad compared to other species, it would make tempting prey to a large variety of generalist predators, including primates and other mammals, lizards, snakes and birds,” says Kusamba, from the Centre de Recherche en Sciences Naturelles, DRC. “Many of these predators use vision to find their prey, and because the viper is deadly venomous, they probably recognise the distinctive, contrasting markings from a considerable distance and avoid the toad because of them, receiving a threatening hiss if the appearance doesn’t put them off.”
Perhaps the best-known examples of Batesian mimicry are in butterflies, where around a quarter of over 200 Papilio swallowtail butterfly species are non-toxic impersonators of toxic ones. Other examples from the animal kingdom include comet fish that fool predators into thinking their tail is a moray eel‘s head, the Brazilian galliwasp lizard that mimics a toxic millipede, and zebra sharks that take on the coloration and undulating movements of venomous sea snakes. Many harmless snakes mimic venomous ones, and some caterpillars, legless lizards, and even birds are able to do so. However, the current study is the first to identify an amphibian mimicking a venomous snake.
This 2015 video is about a male moor frog. He is blue during the mating season.
Moor frows are rare in the coastal sand dunes of the Netherlands: they live there only on Texel, and on Schouwen in Zeeland province.
Natterjack toads are rather common on Texel.
Until about 1980, edible frogs were absent on Texel. After that, people introduced them, and they now live in most areas of the island.
This 2008 video is called A strawberry poison dart frog mother checks up on her tadpole brood.
Imprinting on mothers may drive new species formation in poison dart frogs
What do marrying one’s parents, Oedipus complex have to do with evolution?
October 3, 2019
Summary: By rearing frogs with parents — or foster parents — of different colors, biologists discovered that behavior in response to color may be more important than genetics in the evolution of new species.
The old saying that people marry their parents may be true for poison dart frogs, and it may even lead to the formation of new species, according to a new study in Nature based on work at the Smithsonian Tropical Research Institute (STRI).
Strawberry poison dart frogs live on the mainland in Panama’s Bocas del Toro province and have been isolated on islands in the archipelago that formed during the past 10 million years as sea level rose. Only a single color morph exists on some islands — orange or green, for example, but on other islands several color morphs exist together, like blue and red frogs.
“In the past, people assumed that this group of brightly colored poison dart frogs were warning predators that their skin is toxic,” said Corinne Richards-Zawacki, research associate at STRI and professor of biological sciences at the University of Pittsburgh. “But predators don’t seem to care what color the frogs are, at least based on our earlier experiments. That’s why we started asking whether the way they choose mates might lead to populations of different colors on different islands.”
The team set up three different situations: baby frogs raised with two parents of the same color (red baby, red parents), baby frogs raised with each parent a different color (red baby, one red and one blue parent) and baby frogs raised by foster parents of a different color (red baby, blue parents). In each case they asked which color the female offspring would choose as mates and which color the male offspring would perceive as a rival.
“We discovered that female frogs with parents of the same color tended to choose mates of that same color, whereas frogs with foster parents of a different color would choose mates the color of the foster parents,” said Yusan Yang, who is completing her doctoral thesis at the University of Pitts-burgh. “The same was true for male-male aggression. This tells us that imprinting was more important than genetics when it comes to shaping these behaviors that are based on color.”
When baby frogs were raised with one parent of the same color and one parent of a different color, females chose mates the color of their mother, and males chose rivals the color of their mother, indicating that maternal imprinting was probably more important than paternal imprinting.
They also created a mathematical model showing that male aggression based on imprinting, in concert with female mate choice based on imprinting was enough to cause a scenario to evolve, where like mates with like, which could lead to two color morphs becoming separate species.
“We’re fascinated by the idea that behavior can play such an important role in evolution,” Richards-Zawacki said.