Boa
The name "boa" means "large serpent" in Latin. Growing up to 30 feet in length and 280 pounds, the boa inhabits moist, wooded and grassy environments throughout North and Central America, Africa, Asia, Madagascar and the Pacific Islands. There are approximately 41 species of boa, with the rubber boa (Charina bottae) and rosy boa (Lichanura trivirgata) being the only species indigenous to the United States.
The boa constrictor is a species of boa, however, "constrictor' also describes the general predatory habits of boas as a whole. After striking prey with their fangs, boas encircle their bodies around their victim, squeezing them to death by suffocation. Boas are categorized in the class Reptilia, order Squamata.
Python
Pythons are distributed in Asia, Australia, Madagascar and Africa. They live in moist, green habitats such as savannas, rain forests, swamps and grasslands. Consisting of 33 species, pythons weigh up to 250 pounds and grow up to 33 feet. Pythons are non-venemous, and like boas, they coil their bodies around their prey, killing them by asphyxia. Pythons are also grouped in the class Reptilia, order Squamata.
Anaconda
Also called "water boas", anacondas inhabit the wetlands and rain forests of South America. There are four species of anaconda, with the green anaconda (Eunectes murinus) being the largest snake in the world. They weigh up to 550 pounds, have a diameter of up to 12 inches and grow up to 30 feet long. As are pythons and boas, anacondas are also predatory constrictors, and are categorized in the class Reptilia, order Squamata.
Classifications
Even though boas, pythons and anacondas share the same biological class and order; they differ in family classification. Boas and anacondas belong to the family Boidae; with anacondas actually being a species of boa. Most classifications categorize pythons in the family Pythonidae; while a few list them in the family Boidae and subfamily Pythonidae. So for practical purpose, boas represent a group of snakes; anacondas are a type boa within that group; and pythons are a closely related but different kind of snake.
Lifestyle Comparisons
Boas, pythons and anacondas are meat eaters that feed off a wide range of animals including birds, rabbits, rodents, wild pigs and turtles. However, possibly because anacondas have a much larger girth than boas and pythons, anacondas are also known to eat larger prey including jaguars. Boas and pythons live up to 35 years; whereas anacondas live up to 10 years. Boas, pythons and anacondas all live around and swim in water; but anacondas spend a larger percent of their life in the water itself. Also, pythons lay eggs, however, boas and anaconda give birth to live newborns.