Relatives of the Piranha

Silver Dollars

• There are numerous types of "silver dollar" fish, but the most common type is the "Metynnis hypsauchen." These fish are named for their silver color and for having a nearly circular shape. The fish of the Metynnis genus usually reach lengths of up to 7 inches. The spotted metynnis (Metynnis maculatus) is of the same family but has a longer shape than the more common silver dollars; they also have darker spots along their silver scales.

Hooks

• The Hook Silver Dollars are of the Myleus genus. These fish have a very bright silver color, and some species, known as "redhooks," also have shades of orange or other bright colors along the tips of their fins. Most species of this type grow to about 5 inches in length. They are most common in South America, especially the northern area, but the redhooks can also be found in Venezuela, the Amazon Basin, Guianas and Suriname.

Tambaqui

• The tambaqui is a specific type of pacu fish, which are known as the "fruit eating piranha." These are among the largest of the piranha's relatives, as they can grow to 38 inches long. They are common in the Amazon and Orinoco water systems as well as other places in South America. These fish primarily feed on seeds that fall into the water, possessing jaws that can specially handle harder foods.

Red-Bellied Pacu

• The red-bellied pacu (Piaractus brachypomus) is the most common of the Piaractus genus. Its common name comes from the splotches of red along the underside of its belly in contrast to the rest of its silver color. The fish is common in the upper and middle waters of the Amazon. This fish usually grows to 18 inches and weighs 25 kilograms, and it primarily consumes bugs and decaying plants.