Question

what are morphological characteristics of amphibians???

Answer 1

An amphibian's very thin skin isn't covered by fur, feathers, or scales. This makes them vulnerable to dessication and abrupt temperature change, but also offers several advantages. Amphibians can breath through the entire surface of their bodies. In the case of the lungless salamanders (Plethodontidae), gas exchange through the skin alone provides sufficient oxygen.

Water is also absorbed through an amphibian's skin making drinking unnecessary. Even in areas where open or running water is scarce, an amphibian's skin can absorb moisture from damp soil. Aquatic species would absorb too much water were it not constantly being expelled by their kidneys.

Amphibians display a startling variety of colour which results from different combinations of pigments within their skins. These patterns of colouration are usually designed to provide some form of defence from predators.
Amphibians can leave a bad taste in your mouth...


In the case of the grey tree frog (Hyla versicolor), colour is used to mimic the bark of lichen-covered trees, effectively hiding it from hungry eyes. By contrast, the poison dart frogs of South America use colour to attract attention and convey a message of warning: "eat me and die!" Similarly, the red eft of the red spotted newt (Notophthalmus viridescens) is named for its conspicuous colour which warns potential predators of the poison it can secrete from glands in its skin.
In the amphibian world, poison or "granular" glands are not the exception, but the rule. Nearly all amphibians can secrete toxins from their skins but most are only mildly poisonous. However, if you handle an American toad roughly, and then touch your lips, you may experience numbness for hours; eat the toad and you will feel thoroughly ill!
The mucous-producing glands in an amphibian's skin are what give this group their slimy reputation, but they also serve a very important purpose. The mucous moistens the skin, optimizing oxygen absorption and providing a thin layer of protection.
In some drier areas, a thin mucous layer isn't enough protection.

Phyllomedusa sauvagei is a large South American tree frog which spends much of its time in tree tops where the wind and heat can cause rapid water loss from evaporation. When P. sauvagei settles into a resting pose, special glands in its skin secrete a waxy substance which the frog then rubs all over its body. When dry, the waxy coat provides enough waterproofing to lower the frog's rate of water loss close to that of a desert iguana!

In addition to lubricating and protecting the skin, glands can function in communication. For example, "hedonic" glands produce pheromones used in courtship. The use of chemical signals is particularly important in the salamanders since they can't vocally announce their sexual readiness as the frogs do.

hope it helps :)))))

Answer 2

thank you... one more ques, can this characteristics used for species identification???

Answer 3

Cite your sources:

http://www.aquatic.uoguelph.ca/amphibians/books/book2/bookframe1.htm