AY Honors/Life cycle of a frog
A frog is a type of fresh-water amphibian of the order anura in the class amphibia. Water frogs spend their lives in or near a water source, while tree frogs live in moist environments but not actually in the water.
The frog's lifecycle involves several stages. The female frog lays her eggs in a sheltered area of a shallow pond or creek, where they will be sheltered from the current and from predators. The eggs, known as frogspawn hatch into tadpoles before gradually developing into adult frogs.
frog from the US Fish and Wildlife Public domain photo library
Many species of frog secrete toxins from their skin when under threat. These toxins deter predatory animals from eating them, and some are extremely poisonous to humans. The natives of the Amazon area extract curare from the poison arrow frog.
Frogs are a form of natural environmental barometer, because they are extremely susceptible to the effects of water pollution. In many parts of the world the frog population has declined drastically over the last few decades, and in other areas, large numbers of frogs are born deformed due to this pollution.
The most famous frog would have to be Kermit the Frog, and in Australia the Freddo frog is a popular confectionery treat.
FURTHER READING
- The Froggy Page - http://www.frogsonice.com/froggy/
- The MNCS Frog Project (a study into deformed frogs) - http://www.mncs.k12.mn.us/html/projects/Frog/frog.html
- The Whole Frog Project (virtual frog dissection and anatomy) - http://www-itg.lbl.gov/ITG.hm.pg.docs/Whole.Frog/Whole.Frog.html
- Water Frog Info Pool - http://evolution.genetics.washington.edu/waterfrogs.html
- http://raysweb.net/specialplaces/pages/frogsdecline.html