Tag Archives: Achatinella swiftii var. Newcomb

Achatinella apexfulva (Dixon)

Yellow-tipped Oahu Tree Snail (Achatinella apexfulva)

The tree snails of the genus Achatinella are only found on the island of O’ahu in the Hawaiian archipelago; 41 species are currently accepted, of which about 20 may still survive.

All species inhabit trees and shrubs where they feed on fungi by scraping them from the surfaces of leaves or trunks; the snails are hermaphroditic and give birth to live young, however, only to a few each year. The snails can live to about ten years or even more, the growth rate is very low, and they reach maturity only with about six years. 

The tree snails are very vulnerable to loss of individuals through over-collecting, but also to habitat destruction and especially to the introduction of predators like rats, or more recently the snail-eating Rosy Wolfsnail (Euglandina rosea (Férussac)). [1]


The Yellow-tipped Oahu Tree Snail was indeed the first member of its genus to reach Europe – as part of a shell lei, given by native Hawaiians to George Dixon, a British ship captain in 1786, and to be scientifically described – in 1789.

The species was restricted to some of the ridges of the Ko’olau Mountains, where it was last found in 1985. [1]

The shells reach sizes of about 1,9 cm in height; they are dextral or sinistral and are quite variably colored; the embryonic whorl might be yellow, the following whorls are blackish brown to chestnut-colored, sometimes with some whitish streaks and spiral lines; the narrow suture is light-edged; the moderately thickened lip is flesh- to salmon-colored while the columellar fold is nearly white; the aperture is bluish white within. [1]


The species was last seen in the wild at the Poamoho Trail and was considered extinct in the wild since then; a little captive population (brought into captivity in 1997) was all that was left of this species. This population, however, did not breed and finally was down to a last surviving individual. 

This individual, named George (see photo below), died today (1. January 2019) at the age of 14 years, an exceptional age for an invertebrate species. [2]



[1] Recovery Plan for the O’ahu Tree Snails of the genus Achatinella. U.S. Department of the Interior Fish and Wildlife Service. Region One, Portland, Oregon. April 1993
[2] Jacina Bowler: Lonely George – A Hawaiian Tree Snail – Has Died, Taking His Species With Him. Science Alert January 9, 2019


Photo: Brenden Holland

(under creative commons license (4.0))


edited: 08.06.2021