The Boidae, commonly known as boas or boids, are a family of nonvenomous snakes primarily found in the Americas, as well as Africa, Europe, Asia, and some Pacific islands. Boas include some of the world's largest snakes, with the green anaconda of South America being the heaviest and second-longest snake known; in general, adults are medium to large in size, with females usually larger than the males. Six subfamilies comprising 14-15 genera and 54-67 species are currently recognized.

thumb|left|Cloaca region of a Boa constrictor with spurs (rudimentary hindlegs) Both families share a number of primitive characteristics. Nearly all have a relatively rigid lower jaw with a coronoid element, as well as a vestigial pelvic girdle with hind limbs that are partially visible as a pair of spurs, one on either side of the vent. In males, these anal spurs are larger and more conspicuous than in females. A long row of palatal teeth is present, and most species have a functional left lung that can be up to 75% as large as the right lung.

Boids are, however, distinguished from the pythons in that none has postfrontal bones or premaxillary teeth, and that they give birth to live young. When labial pits are present, these are located between the scales as opposed to on them. Also, their geographical distributions are almost entirely mutually exclusive. In the few areas where they do coexist, the tendency is for them to occupy different habitats.

Reproduction

Most species of boa are ovoviviparous, with females giving birth to live young. This is in contrast to the pythons, which lay eggs (oviparous).

Subfamilies

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!bgcolor="#f0f0f0"|Subfamily

Almost all of the non-boine boids are frequently elevated to their own full families: Calabariidae/inae, Candoiidae/inae, Charinidae/inae, Erycidae/inae, Sanziniidae/inae, and Ungaliophiidae/inae.

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File:Boa constrictor, Vaňkovka, Brno (2).jpg|Boa type species; the boa constrictor (B. constrictor)

File:Puerto rican boa.jpg|Chilabothrus type species; the Puerto Rican boa (C. inornatus)

File:Corallus hortulanus head, Peru.jpg|Corallus type species; the Amazon tree boa (C. hortulana)

File:EpicratesCenchriaCenchria1.jpg|Epicrates type species; the rainbow boa (E. cenchria)

File:Sucuri verde.jpg|Eunectes type species; the green anaconda (E. murinus)

File:Pazifikboa.jpg|Candoia type species; the Pacific ground boa (C. carinata)

File:Calabar Serpent2.jpg|Calabaria type species; the Calabar python (C. reinhardtii)

File:Charina bottae 190641815.jpg|Charina type species; the northern rubber boa (C. bottae)

File:Eryx jaculus.jpg|Eryx type species; the javelin sand boa (E. jaculus)

File:Lichanura-trivirgata.jpg|Lichanura type species; the desert rosy boa (L. trivirgata)

File:Dumeril's Madagascar ground boa (Acrantophis dumerili) male head Isalo.jpg|Acrantophis type species; Dumeril's boa (A. dumerili)

File:Ferme des Reptiles - Sanzinia madagascariensis 02.jpg|Sanzinia type species; the Madagascar tree boa (S. madagascariensis)

</gallery>

See also

  • List of boine species and subspecies
  • List of erycine species and subspecies

Notes

References

Further reading

  • Kluge, A.G. 1991. Boine Snake Phylogeny and Research Cycles. Misc. Pub. Museum of Zoology, Univ. of Michigan No. 178. PDF at University of Michigan Library. Accessed 8 July 2008.