Eunectes murinus (derived from the Greek "Ευνήκτης" meaning "good swimmer" and the Latin "murinus" translated into "he who predates on mice") is a non-venomous boa species found in South America. It is the most massive of all known snake species. The term "anaconda" (without any further description) often refers to this species, though the term could also apply to several other members of the genus.
The Green Anaconda is one of the world's longest snakes, reaching more than 5 m (17 ft) long. Reports of anacondas 35–40 feet or even longer also exist but such claims need to be regarded with caution as no specimens of such lengths have ever been deposited in a museum and hard evidence is required. There is a $50,000 cash reward for anyone that can catch an anaconda 30 feet or longer, but the prize has not been claimed yet. Although the reticulated python is longer, the anaconda is the heaviest snake. The longest (and heaviest) scientifically recorded specimen was a female measuring 521 cm (18.1 ft) in length and weighing 97.5 kg (214 lbs).
The color pattern consists of olive green background overlaid with black blotches along the length of the body. The head is narrow compared to the body, usually with distinctive orange-yellow striping on either side. The eyes are set high on the head, allowing the snake to see out of the water while swimming without exposing its body. http://bit.ly/dsV7Db