THE SNOW BOA
By Marc Spataro & Peter Kahl

This is the first snow boa ever produced. This beautiful snake was 10 months old when photographed.

For many reasons, boa constrictors (Boa constrictor) have been a mainstay in the pet industry for some 40 years. As a rule, boa constrictors possess mild dispositions, do not obtain giant sizes and do not require a great deal of technical husbandry to maintain in captivity.

This beautiful constrictor has one of the largest natural ranges of any snake species, ranging from northern Mexico through Central America into South America to central Argentina. There are also several insular populations found in both the Atlantic and Pacific Oceans. Numerous subspecies are recognized, including the Central American boa constrictor (B.c.imperator), South American boa constrictor (B.c.constrictor), Amaral's or Bolivian boa constrictor (B.c.amarali), Argentine boa constrictors (B.c.occidentalis), Peruvian boa constrictors (B.c.ortonii), St. Lucia boa constrictor (B.c.orophias), clouded boa constrictor (B.c.nebulosus), black-bellied boa constrictor (B.c.melanogaster) and Rio Tumbes boa constrictor (B.c.longicauda). Further research is needed to confirm the validity of all the boa constrictor subspecies.

With such a large range, boas have evolved into a species exhibiting extreme geographic variation, the three most obvious being size, color, and pattern. These variations can be correlated with the locality from which the specimen was found. While some boas obtain a mature size of only 4 feet, others may reach lengths greater than 10 feet. Pattern and color variability is even greater within this species. The southern most subspecies, the Argentine boa (B.c.occidentalis), is a very dark specimen, almost black, while equatorial specimens, such as the clouded boa (B.c.nebulosus), can be very pale in color.

These albinos represent two different bloodlines produced by Peter Kahl.

With the boas' ever-growing popularity, a demand exists to produce animals with exceptionally odd colors and patterns. Boa constrictors are on their way to becoming the "corn snake" of the boa and python enthusiasts' world. So far, seven naturally occurring variations of color and pattern have been demonstrated to be inheritable genetic traits: albino, anerythristic, striped, hypomelanistic, "arabesque", "motley" and "jungle."

One of us, Peter Kahl, has successfully produced beautiful color and pattern variations in boa constrictors for eight years. Pete produced the first captive-born albino in 1992, opening the door toward continued variations. In order to maximize the genetic variability in a linebreeding project, Pete has bred the original albino male to several different females. As a result, each specific bloodline varies beautifully in color, pattern and contrast. While one bloodline has a high pink contrast throughout, another has varying shades of white, red and orange. Pete has now begun to cross several of the inheritable variations into the albino lineage. This increases both the genetic variability of the albino bloodlines and creates the possibility of new and beautiful boa constrictors.

Breeding an anerythristic boa like this one (note there is no red pigment in the tail or body) to an albino produces double het offspring for albinism and anerythrism. Breeding the hets together produces various percentages of four different color phases, one of which is the snow boa.

Peter Kahl's latest project involves the combination of two recessive traits, albinism and anerythrism, to create a new lineage of boa constrictor known as the snow boa. The first snow boa was produced during the 1996 breeding season. Pete started this project five years ago by breeding an albino male to an anerythristic female. Anerythristic boas do not produce red pigment in the skin, a condition similar to albinism in which no black pigment is produced. The offspring from this litter are normal in appearance, but are heterozygous gene carriers for two recessive traits, albinism and anerythrism. These offspring are commonly referred to as double hets or double heterozygous for snow. When these double hets are bred to each other, the resulting litter of babies will be comprised of four different color phases. On the average, 9/16 of the litter will appear normal, 3/16 will be albino, 3/16 will be anerythristic and 1/16 will be a beautiful snow boa.

The appearance of the snow boa is whiter than that of an albino boa and lacks all red pigment, replacing it with a silvery shade of white. At birth, the pattern is faintly defined as a lavender color, giving the snake a mystical appearance. Pete has already started to breed several different bloodlines of albinos and anerythristics to ensure that breeders and enthusiasts establish proper genetic diversity in their collections.

Three litter mates - an albino, an anerythristic, and snow, shown here.

The snow boa will surely become one of the most popular boa constrictor color variants available to herpetoculturists. The snow boa is, in a sense, the first truly domestic lineage of boa constrictor. The genetic variation of "snow" is a man-made condition never observed in nature. Its creation is the most tangible evidence of the successes of herpetoculture. The snow boa is the first of many exciting and beautiful boa constrictors to come.