Capybara
The capybara ("Hydrochoerus hydrochaeris") is a mammal native to South America. It is the largest living rodent in the world. Also called chigüire, chigüiro (in Colombia and Venezuela) and carpincho, it is a member of the genus "Hydrochoerus", of which the only other extant member is the lesser capybara ("Hydrochoerus isthmius"). Its close relatives include guinea pigs and rock cavies, and it is more distantly related to the agouti, the chinchilla, and the coypu. The capybara inhabits savannas and dense forests and lives near bodies of water. It is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 10–20 individuals. The capybara is not a threatened species but it is hunted for its meat and hide and also for grease from its thick fatty skin, which is used in the pharmaceutical trade.
Largest organisms
The lion's mane jellyfish ("Cyanea capillata") is the largest cnidaria species, of the class Scyphozoa. The largest known specimen of this giant, found washed up on the shore of Massachusetts Bay in 1870, had a bell diameter of , a weight of . The tentacles of this specimens were as long as and were projected to have a tentacular spread of about making it one of the longest extant animals.
The largest roundworm, "Placentonema gigantissima", is a parasite found in the placentas of sperm whales which can reach up to in length.