Achatinella abbreviata   (Reeve)


 
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Short Oahu Tree-Snail
(Achatinella abbreviata)

 
syn. -

 
distribution:

Hawai'i Islands: O'ahu

 
local name:

Kahuli (Hawaiian)
Pupu kani oe (Hawaiian)
Pupu kuahiwi (Hawaiian)

 
size: ca. 2 cm (shell height)

extinction date: last recorded 1963

 
The snail species of the genus Achatinella occur exclusively on the island of O'ahu in the Hawaiian island chain.

Altogether about fourty species have been described, only about ten of which are still extant, added to that are countless subspecies, varieties and colour morphs, which most often also bear scientific names, certainly unjustified in most cases.

The animals reach an astonishing age of ten to twenty years, however, they reach maturity with about one year. They are live-bearing, but give birth to only about four to seven young each year.

The first species disappeared already shortly after the colonisation of the Hawaiian Islands by Polynesians, due to the clearing of large areas of lowland forest for agriculture. Additional species follwed with the emergence of the first European settlers, on one side as well by the deforestation of large areas of native forest, but on the other side also by the direct collecting of the very variable coloured shells.

Added to this are three introduced rat species, first the Polynesian Rat (Rattus exulans (Peale)), imported by the Polynesians, and then the Brown Rat (Rattus norvegicus (Berkenhout)) as well as the Black Rat (Rattus rattus (L.)), both of which have been introduced by the Europeans. All three species are known to crack the shells and to eat the snails.

Perhaps the greatest threat comes from another introduced species, the snail-eating Rosy Wolfsnail (Euglandia rosea (Férussac)), which was intentionally imported in the year 1955 to the Hawaiian Islands, initially to combat the likewise introduced Giant African Land Snail (Achatina fulica (Bowdich)), which in turn caused significant damages in the agriculture.

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The Short Oahu Tree-Snail, one of the most colourful and variable species within the whole genus, lived in the Ko'olau Mountains, where the last living individuals were found in the year 1963.

 
left:

Short Achatinella Tree-Snail (Achatinella abbreviata)


Photo from: 'G. W. Tryon; H. A. Pilsbry: Manual of Conchology. Second series: Pulmonata, Vol. 22, 1912-1914'

http://www.biodiversitylibrary.org

 
References: