List of largest snakes
The largest living snakes in the world, measured either by length or by weight, are various members of the Boidae and Pythonidae families. They include anacondas, pythons and boa constrictors, which are all non-venomous constrictors. The longest "venomous" snake, with a length up to , is the king cobra, and the heaviest venomous snake is likely to be the Gaboon viper (which also has the longest fangs and delivers the largest amount of venom) or possibly the Eastern diamondback rattlesnake – all three of which reach maximum weights in the range of . There are eleven living snakes , listed below according to their maximum known or reported mass, that have a maximum mass that may reach or exceed . Pending the acceptance of its taxonomic status, the Bolivian anaconda ("Eunectes beniensis") may also merit inclusion, and the northern and southern variations of African rock python could be considered separately. In terms of length, in addition to those listed here, there are two other species that may possibly reach a length of or more – the Oenpelli python ("Morelia oenpelliensis") and the olive python ("Liasis olivaceus") – however, the information available about those species is rather limited. The Oenpelli python, in particular , has been called the rarest python in the world. It is important to be aware that there is considerable variation in the maximum reported size of these species, and most measurements are not truly verifiable, so the sizes listed should not be considered definitive. In general, the reported lengths are likely to be somewhat overestimated. In spite of what has been, for many years, a standing offer of a large financial reward (initially $1,000 offered by U.S. President Theodore Roosevelt in the early 1900s, later raised to $5,000, then $15,000 in 1978 and $50,000 in 1980 ) for a live, healthy snake over long by the New York Zoological Society (later renamed as the Wildlife Conservation Society), no attempt to claim the reward has ever been made. Although it is generally accepted that the reticulated python is the world's longest snake, most length estimates longer than 6.35 m (20 ft 10 in) have been called into question. It has been suggested that confident length records for the largest snakes must be established from a dead body soon after death, or alternatively from a heavily sedated snake, using a steel tape and in the presence of witnesses , and must be published (and preferably recorded on video). At least one reticulated python was measured under full anesthesia at , and somewhat less reliable scientific reports up to have appeared. Remarkable individual specimens. Individual specimens considered among largest measured for their respective species include the following: