9 extant species remained in 2014[1][2] Achatinella is a tropical genus of colorful land snails in the monotypic Achatinellidae subfamily Achatinellinae.

The IUCN lists a number of Achatinella species as extinct and the remainder as critically endangered.

[5][4] Achatinella species shells are diverse in patterns, colors, and shapes, but all average about 0.75 in (1.9 cm) in length.

Most have smooth glossy, and oblong or ovate shells which show a variety of colors, including yellow, orange, red, brown, green, gray, black, and rainbow.

Genus Achatinella Swainson, 1828: The dextral or sinistral shell is imperforate or minutely perforate, oblong, ovate or globose-conic; smooth or longitudinally corrugated, with only weak traces of spiral sculpture.

These are the most generally distributed of the Achatinella species and show a prolific area of intergrading color patterns.

[4] These tree snails are nocturnal, and feed by grazing fungus which grows on the surface of native plant leaves.

They also feed on cornstarch, which can be spread in terraria with water and on cultures of sooty mold grown on laboratory agar.

[4] Because growth rate and fertility are very low, these snails are especially vulnerable to loss of individuals through human collection, through predation, or because of other disturbances.

The summer palace of King Kamehameha III was called Kaniakapupu ("the singing of the land shells") because of the many snails which once inhabited the area during his lifetime.