Achatinella apexfulva | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Order: | Stylommatophora |
Family: | Achatinellidae |
Genus: | Achatinella |
Subgenus: | Achatinella |
Species: | †A. apexfulva |
Binomial name | |
†Achatinella apexfulva | |
Synonyms | |
List
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Achatinella apexfulva is an extinct species of colorful, tropical, arboreal pulmonate land snail in the family Achatinellidae, once present on Oahu, Hawaii. A. apexfulva is the type species of the genus Achatinella . The specific name, apexfulva, meaning "yellow-tipped", refers to the yellow tip of the snail's shell. Inspired from the taxon, the species has been given common names such as yellow-tipped Oʻahu tree snail [3] or Hawaiian yellow-tipped tree snail. [4] Officially, it is listed as ‘critically endangered’ by the IUCN, however, this is because its conservation status has not been updated in 28 years. [1]
The family Achatinellidae, to which Achatinella apexfulva belongs, represents a diverse adaptive radiation. All species of tree-snail in Hawaii are believed to have come from a single ancestral snail. How that ancestral snail made the 3,800 kilometres (2,400 mi) trip across the ocean is unknown. A longstanding theory is that a bird carried a notably smaller ancestor across the ocean and dropped it on the islands, as bird mediated dispersal has been documented in other snail species. Alternative theories include that it floated across the ocean on a mat of debris, or that it island-hopped across the Pacific in a combination of the theories. Within the Achatinellidae, A. apexfulva belongs to the Oahu clade, which evolved on Oahu island and includes most other members of the genus Achatinella. [5]
This species was endemic to forests of the island of Oahu in the Hawaiian archipelago, United States, but is now extinct. [6] It was listed as federally endangered since 1981. [7] A major cause of its population decline in the wild was predation by the rosy wolfsnail. The rosy wolfsnail, a central-American native, was introduced to Hawaii in the 1950s to control agricultural pests. [8] However, as a carnivore of other snails it does not discriminate in its choice of food and has been the cause of at least eight other snail extinctions in Hawaii. [9]
Other causes of the snail's decline included loss of habitat due to deforestation, introduction of rats, and the introduction of Jackson's chameleon. [10] The problems that A. apexfulva faced are not unique: estimated extinction rates in the family Achatinellidae range between 75% and 90%. [5] The International Union for Conservation of Nature's last study on A. apexfulva was conducted in 1996 and listed the species as Critically Endangered. [1]
In 1997, in response to rapidly dwindling populations, all known remaining specimens of A. apexfulva were collected and bred in captivity. Most offspring died of unknown causes, but one successful offspring was born. This individual was named George, after Lonesome George, a Pinta Island tortoise from the Galapagos Islands who was also the last of his kind. [11] By April 2011, George was the only remaining member of the species. [12] [13] In January 2019, George died at age 14 – leaving the species reportedly extinct. [14] [8] [15] [16]
While A. apexfulva lived on the leaves of trees, it was not herbivorous. Its diet consisted of algae and mold that it ate off leaves. [10]
Achatinella is a tropical genus of colorful land snails in the monotypic Achatinellidae subfamily Achatinellinae.
Achatinella abbreviata, an Oʻahu tree snail, is an extinct species of colorful tropical tree-living air-breathing land snail, an arboreal pulmonate gastropod mollusk in the genus Achatinella.
Achatinella bellula is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to the Hawaiian island of Oahu in the United States. No more than five specimens have been observed since 1979.
Achatinella byronii is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to Oahu, in the Hawaiian Islands.
Achatinella fulgens is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc within the Achatinella genus of the family Achatinellidae. The species is one of a collection of snail species commonly referred to as Oʻahu tree snails or pupu kuahiwi in the Hawaiian language.
Achatinella fuscobasis is a species of air-breathing land snail, a terrestrial pulmonate gastropod in the family Achatinellidae. This species is endemic to Hawaii.
Achatinella lila is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to the northern Ko‘olau Mountains, Oahu.
Achatinella livida is a critically endangered species of air-breathing land snail in the family Achatinellidae. This species is endemic to Oʻahu, Hawaiʻi.
Achatinella mustelina is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Achatinellidae. This species is endemic to the Waianae Range of the island of Oahu, Hawaii.
Achatinella pulcherrima is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to the island of Oahu in Hawaii.
Achatinella pupukanioe is a species of land snail, a gastropod in the family Achatinellidae. It is endemic to Hawaii.
Achatinella sowerbyana is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to Hawaii.
Achatinella taeniolata, an O'ahu tree snail, is a species of colorful, tropical, tree-living, air-breathing land snail, an arboreal pulmonate gastropod mollusc in the family Achatinellidae.
Achatinella viridans is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Achatinellidae. This species is endemic to Hawaii.
Achatinella vulpina is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Achatinellidae. This species is endemic to Hawaii.
Auriculella ambusta is a species of air-breathing tropical land snail, a terrestrial pulmonate gastropod mollusc in the family Achatinellidae. This species is endemic to the Hawaiian Islands.
Newcombia cumingi, common name Newcomb's Tree snail, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Achatinellidae. This species is endemic to Hawaii, the United States.
George was a snail of the species Achatinella apexfulva, and the last known individual of his species.
Michael Gale Hadfield is an invertebrate biologist and professor emeritus at the University of Hawaiʻi at Mānoa. His research has focused on the larvae of marine invertebrates and native tree snails in Hawai'i. He retired in 2013, but has remained active in research and was recognized in 2023 as one of the top ecology and evolutionary scientists in the U.S. and the world.
The first Achatinellid shells brought to Europe, so far as we know, were obtained by Captain George Dixon, who visited the Hawaiian Islands in 1786 and 1787. They were strung on a lei or necklace, which seems to have been made entirely of Achatinella apexfulva and A. decora. It appears that four specific names were based upon these specimens.
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