Amastridae

Amastridae is a family of terrestrial gastropod mollusks commonly known as the "tree snails". They are endemic to the Hawaiian Islands, with the majority of species found on the island of Oahu. These snails are characterized by their dextral (right-handed) shells, which are typically globose or trochiform and range in size from small to medium. The shell coloration varies greatly, often exhibiting bands, streaks, or mottling in shades of brown, yellow, and white.

The Amastridae family is known for its remarkable species diversity, with over 200 described species, although many are now extinct. Historically, these snails played a significant role in the Hawaiian ecosystem, contributing to nutrient cycling and serving as a food source for native birds. However, habitat loss due to agriculture and development, coupled with the introduction of invasive predators like the predatory rosy wolfsnail (Euglandina rosea), has led to the severe decline of many Amastridae species. As a result, a large proportion of the family is listed as extinct or endangered, making conservation efforts critical for the survival of the remaining species. Their decline serves as a stark example of the impact of human activities and invasive species on island biodiversity.