Eunectes murinus (derived from the Greek ευνήκτης meaning "good swimmer" and the Latin murinus meaning "of mice" for being thought to prey on mice), commonly known as the green anaconda, is a non-venomous boa species found in South America. It is the largest, heaviest, and second longest (behind the reticulated python) known extant snake species. The term anaconda (without further qualification) often refers to this species, though the term could also apply to other members of the genus Eunectes. Other common names include common anaconda and water boa.The green anaconda is the world's heaviest and one of the world's longest snakes, reaching more than 6.6 m (22 ft) long. More typical mature specimens reportedly can range up 5 m (16 ft), with the females, at around a mean length of 4.6 m (15 ft), being generally much larger in adulthood than the male, which averages around 3 m (9.8 ft). Weights are less well studied, though will reportedly range from 30 to 70 kg (66 to 150 lb) in an average-range adult. It is the largest snake native to the Americas. The remote location of the snake's habitat has historically made locating, capturing, and returning specimens difficult. Transporting very large specimens to museums, especially before substantial decay, is difficult (though this has not prevented the return of much larger and more cumbersome crocodilian specimens). Skins can stretch substantially, increasing the snake's size by more than 50% if stretched during the tanning process. Reports without physical proof are considered dubious if from nonscientists, as such individuals may at worst be more interested in promoting themselves or telling a good tale, or at the least may not be sufficiently trained in proper measurement methods. Observational reports of animals which were not captured are even more dubious, as even trained scientists often substantially overestimate the size of anacondas prior to capture. According to the Guinness Book of World Records, this species has been perhaps subject to the most extreme size exaggerations of any living animal. At the same time, it is difficult to argue a maximum possible or plausible size, because anacondas are known to continue to grow throughout their lives. Older reports in particular could include individuals which, in times of less pressure from humans, lived longer lives and thus reached greater sizes.