O'ahu tree snail

The Oahu tree snails comprise the genus Achatinella; there are around 40 species of Oahu tree snail endemic to Hawaiian island of O`ahu. All 40 species are listed under United States federal legislation as endangered; the IUCN lists a number of these species as extinct and the remainder as critically endangered.

Oahu tree snails are diverse in patterns, colors, and shapes but all average about 3/4 inch in length. Most have smooth, glossy, and oblong or ovate shells with a variety of colors, including yellow, orange, red, brown, green, gray, black, and white. O`ahu tree snails are currently found in mountainous dry to wet forests and shrublands above 1,300 feet. They are found on trees, are nocturnal, and feed by grazing fungus from the surface of native plant leaves. Although they are occasionally found on introduced plants, it is unknown whether the fungus of these plants provide long-term support for healthy breeding populations. Adult snails are hermaphroditic (having both male and female reproductive organs) and can live for many years. These are live bearing snails (give birth to live snails instead of laying eggs).

Because growth rate and fertility are very low, these snails are especially vulnerable to loss of individuals through collection, predation, or other disturbances. Oahu tree snails were once so abundant and popular on the island they are mentioned in Hawaiian folklore and songs, and their shells were used in lei and other ornaments. The most serious threats to the survival of Oahu tree snails are predation by the introduced carnivorous snail (Euglandina rosea), predation by rats, and loss of habitat due to the spread of nonnative vegetation into higher elevation forests.

Species

 * Achatinella abbreviata
 * Achatinella apexfulva
 * Achatinella bellula
 * Achatinella buddii
 * Achatinella bulimoides
 * Achatinella byronii
 * Achatinella caesia
 * Achatinella casta
 * Achatinella clausinus
 * Achatinella concavospira
 * Achatinella curta
 * Achatinella decipiens
 * Achatinella decora
 * Achatinella dimorpha
 * Achatinella dolium
 * Achatinella faba
 * Achatinella fulgens
 * Achatinella fuscobasis
 * Achatinella juddii
 * Achatinella juncea
 * Achatinella lehuiensis
 * Achatinella lila
 * Achatinella livida
 * Achatinella lorata
 * Achatinella mustelina
 * Achatinella papyracea
 * Achatinella phaeozona
 * Achatinella pulcherrima
 * Achatinella pupukanioe
 * Achatinella solitaria
 * Achatinella sowerbyana
 * Achatinella spaldingi
 * Achatinella stewartii
 * Achatinella taeniolata
 * Achatinella thaanumi
 * Achatinella turgida
 * Achatinella valida
 * Achatinella vestita
 * Achatinella viridans
 * Achatinella vulpina

Reference

 * U.S. Fish and Wildlife Service