Piranhas

= Piranhas =


 * Species name**: //Pygocentrus nattereri//


 * Scientific Classification:**
 * =====Domain===== || =====Eukaryota===== ||
 * =====Domain===== || =====Animalia===== ||
 * =====Phylum===== || =====Chordata===== ||
 * =====Class===== || ===== Actinopterygii ===== ||
 * =====Order===== || =====Characiformes===== ||
 * =====Family===== || =====Characidae===== ||
 * =====Genus===== || =====Pygocentrus===== ||
 * =====Species===== || =====Nattereri===== ||

Habitat:
Piranhas are found in the Amazon basin, Guyanas, Paraguay-Patana, and Sao Francisco River. They normally live in the lentic and lotic environments but hardly survive in cold winters in a specific region. They have a broad region which they happen to be seen in parts of the United States. There climate are often in the warm environments but climate may change drastically.

Physiology:
Piranhas are about 14 to 26 cm long (6 to 10 inches). There jaws have single rows of sharp teeth that looks like triangle shapes. They're quite fast and have a strong sense that will capture preys easy. Piranhas are small but they fit in there environemnt by being competitive which they take up the resources. They mainly live under the bottom of the lake or river because of the darkness which thats how they lay eggs.

[[image:http://static.howstuffworks.com/gif/piranha-eat-cows-1.jpg width="251" height="182" align="left" caption="Hunts in group to catch food."]]Species interactions:
Piranhas normally hunt in groups to protect there own predators such as cormants, calmans, and dolphins. As they hunt in groups they are more vicious to other predators. Piranhas survive by always knowing where all the fishes are. They have to react fast for the next fish can make a next move. Other than fish, Piranhas are capable of eating insects, crustaceans, and even mammals. Basically anything that are in there site.

Reproduction:
Piranhas tend to change to a lighter color as they lay eggs. As they start to reproduce, they get more agressive which for the time being they will remain that way until spawning is done. Depending on water temperature, it will take atleast two or three days for there eggs to hatch. As they wait, Piranhas remove any rocks or stones with their tails and blowing it away. When the nest is ready, the male lures the female to the nest for when it is time she can lay eggs. The male then guards the nest for any predators until it is hatch.

Work Cited:
"Most Ferocious - Piranha." //Extreme Science//. Extreme Science, n.d. Web. 30 Mar 2011. <[]>.

"Piranha." //Wikipedia//. Wikipedia, 26March2011. Web. 30 Mar 2011. <[]>.