Some species of salamanders have lost key elements of the skeleton during their evolution. For example, species within the salamander family Sirenidae have lost their limbs, and are eel-like in appearance. Remarkably, the numbers and shapes of limb bones are not necessarily the same within some salamander species, as is the case of the red-backed salamander (Plethodon cinereus) of North America. Within the same population, individuals of this species can have varying numbers of limb bones, and these structures can vary significantly in size, shape, and degree of calcification.
Salamanders have a protrusile tongue, used for feeding and sensory purposes. Many species are very brightly colored, usually to warn predators of the poisonous nature of the skin of these animals. Some salamanders secrete a chemical known as tetrodotoxin from their skin glands This is one of the most poisonous substances known, and it can easily kill predators that are intolerant of the chemical, as most are.
http://science.jrank.org/pages/5936/Salamanders-Biology-salamanders.html
No comments:
Post a Comment