There are a wide range of species kept by snake enthusiasts today, from so called "beginners" snakes such as the colubrids (corn snakes, king snakes etc.) to large pythons and everything in between. Few however have the majesty and attraction of the boas.
Boas are a privative family of snakes, often confused with their cousins the pythons. In fact they share many traits with the pythons, with the most notable difference often being geography. With a couple of exceptions, boas are from the Americas, while pythons are "old world" snakes.
Boa constrictor is without doubt the best known of the boas, and one of the few snake species that many lay persons can identify. They are a large and powerful snake, with some subspecies capable of growing to lengths in excess of 12 feet. While they are often quite docile and wonderful to handle, their sheer size means that they are only suitable for experienced snake keepers with the experience and room required to keep them.
There are however many smaller species of boa with are more suited to newcomers to snake keeping. Firstly, there are several subspecies of boa constrictor which are considerably smaller than the well known "Red tailed boas". Boa constrictor imperator is very similar in appearance to the red tail, but the males tend to only reach around 6 feet in length (the females, as with most snakes are a little larger).
The Dumeril's boa is a protected species, listed on CITES and as such requires paperwork to prove origin, but they are a beautiful and generally docile snake. Captive bred Dumeril's boas are often available on the pet trade, though their CITES status makes them considerably more expensive than many other boa species.
Smaller again are a number of terrestrial and burrowing boa species. Snakes such as the rubber boa, rosy boa, and Kenyan sand boa don't have the stature and markings of the boa constrictors, but their small size makes them suitable for a beginner to the hobby of snake keeping.
Most boa keepers will agree that there is something about the boas which makes them special. After 25+ years of keeping a wide range of snakes and lizards, it is still the boas which fascinate me the most. They are wonderful snakes, and should certainly be considered by anyone interested in herpetoculture.