Amphibians are fascinating animals that play a critical role in our ecology. In a single weekly blog I can not do them justice. So get out there and keep photographing these important dual-lived creatures. There will be another amphibians blog in the coming months. If you capture something interesting, please send it in and we'll hold onto it for the sequel.
The origin of the word amphibian is from the greek amphibios, meaning "living both in water and on land". Most amphibians actually have two lives. They spend their larval stage in water breathing through gills. As they mature, legs and lungs develop and they lose those gills. Upon completion of this metamorphosis, many amphibians emerge from the water to live primarily on land. A trait unique to amphibians, these vertebrates have smooth, thin skin which aids in their breathing. Most amphibians must keep their skin moist in order to respire, though some groups have evolved different adaptations and strategies to get around this requirement.
Amphibians consist of frogs and toads, salamanders and caecillians (a species not found in North America). Many amphibians are indicator species for ecological health, and they are currently experiencing a mass extinction. Since the early 1980s, amphibian species have been in rapid decline. Living both in aquatic and terrestrial environments, they are impacted doubly due to habitat fragmentation, disease, pesticide use on surrounding farmland and a number of other issues. Read more about this crisis at Amphibian Ark.
This week's blog features five images and a few interesting facts about these intriguing creatures.
1. Frog
There are nearly 5000 frog species, each with its own unique call. And some can project up to a mile.
Image photographed by Sara Darling-Jones.
2. Tree Frog
The most common Tree Frogs in North America, Gray Tree Frogs have the ability to camouflage themselves. These nocturnal amphibians alternate between gray and green to blend in with their surroundings.
Image photographed by Gina Vaughan.
Gray tree frogs spend much of their lives high in trees, coming down only for breeding. Their toes excrete a sticky mucous that, combined with the surface of their toe pads allows them to stick to bark while hanging vertically.
Image photographed by Melissa Penta
3. Toad
Toads have long been thought to have warts that are contagious. This myth has since been debunked and warts are actually caused by a virus which may be transferred between humans. Toads do, however, have parotoid glands on their backs, necks and shoulders. Similar to warts in appearance, these glands excrete a chemical that acts as a neurotoxin to predators. While not dangerous to humans, they are successful in limiting toad predation. Iamge photographed by Elizabeth Traff.
4. Salamander
Salamanders, a name meaning “fire within”, were once thought to be fireproof, and that they may even extinguish fire. In first century AD, naturalist Pliny the Elder tested this theory, resulting in the unfortunate demise of his test subject. Even more bizarrely, it was later conjectured that salamander fur could be woven into fireproof clothing, an utterly ridiculous idea since Amphibians have no hair.
Often confused for lizards, salamanders retain their tails after metamorphosis and spend much of their adult lives under water. Newts, pictured, are semi-aquatic, living both on land and in the water.
The regenerative capabilities of salamanders makes them extremely interesting to researchers. They are able to regrow large amounts of tissue. Lost a limb during a close call with a predator? Not a problem. It will grow back!
Salamander photographed by Christine Chady.