Achatinella sowerbyana Pfeiffer, 1855
Achatinella sowerbyana is tropical land snail endemic to the island of Oahu, Hawaii. This terrestrial gastropod mollusc is in the family Achatinellidae (subfamily Achatinellinae). This species was originally described in 1855 by Pfeiffer and the type specimen likely came from a valley in the Kaipapai-Kaliuwaa region (Pilsbry & Cooke 1913). This species is currently listed on the US Endangered Species list and EOL Hotlist. This species is also called Oahu Tree Snail or Pupu kani oe (Hawaiian name). Synonyms: Achatinella oviformis Newcomb; Achatinella multicolor Pfeiffer; Bulimella sowerbAchatinella sowerbyana is tropical land snail endemic to the island of Oahu, Hawaii. This terrestrial gastropod mollusc is in the family Achatinellidae (subfamily Achatinellinae). This species was originally described in 1855 by Pfeiffer and the type specimen likely came from a valley in the Kaipapai-Kaliuwaa region (Pilsbry & Cooke 1913). This species is currently listed on the US Endangered Species list and EOL Hotlist. This species is also called Oahu Tree Snail or Pupu kani oe (Hawaiian name). Synonyms: Achatinella oviformis Newcomb; Achatinella multicolor Pfeiffer; Bulimella sowerbiana Pfeiffer
Original description:
Pfeiffer, L. 1855. Descriptions of twenty seven new species of Achatineilla, from the collection of H. Cuming. Esq., collected by Dr. Newcomb and by Mons. D. Frick, late Consul-general of France at the Sandwich Islands. Proceedings of the Zoological Society of London 23 [1854]: 1-7. pI. 30. [27 March]
This species is currently listed on the EOL Hotlist and IUCN as Critically Endangered. The entire genus was placed on the U.S. Fish and Wildlife Service Endangered Species List and the State of Hawai‘i’s Endangered Species List in 1981.
Specific management pracitices include:
- Surveys to determine the geographic ranges of all extant species.
- Systematic surveys of all extant populations to determine abundance.
- Systematic surveys to locate unknown populations.
- Conservation of remaining native forests from further loss and/or degradation.
- Control of predators (specifically rodents, Euglandina rosea, and Oxychilus alliarius).
- Loss and degradation of habitat
- Non-native invasive predators (e.g. rodents, Euglandina rosea, Oxychilus alliarius)
- Insufficient information for species assessments.
Primarily arboreal and nocturnal, Achatinella sowerbyana is currently found in mountainous dry to wet forests and shrublands above 1,300 feet. Every species in the Achatinella genus feed by grazing fungus from the surface of native plant leaves (e.g. Ohia; Metrosideros polymorpha). Adult snails are hermaphroditic and are ovoviviparous.
Reference:
U.S. Fish and Wildlife Service. (1992) Recovery Plan for the O’ahu Tree Snails of the Genus Achatinella. U.S. Fish and Wildlife Service, Portland, Oregon, 64 pp. + 64 pp. of appendices + 5 figures
The height of the shell is 18.0 mm and width is 9.0 mm. The shell has 6 whorls and occur in both a sinistral dextral morph. The whorls are slightly convex and sutures are margined. The shell is imperforate, conic-oblong and solid with a slightly convexly-conic spire and an apex that is subacute. The glossy color is tawny buff and slightly streaked with a deeper shade. The aperture is oblique and white within. The strong columellar fold is superior, twisted, and roseate. The peristome is rose-lipped with the outer margin shortly expanded and columellar margin dilated and adnate.
Original description:
Pfeiffer, L. 1855. Descriptions of twenty seven new species of Achatineilla, from the collection of H. Cuming. Esq., collected by Dr. Newcomb and by Mons. D. Frick, late Consul-general of France at the Sandwich Islands. Proceedings of the Zoological Society of London 23 [1854]: 1-7. pI. 30. [27 March]
Current populations are in the Northern Koolau Mountain Range, Oahu, Hawaii. The number of these snails found on a single bush or tree can range from 2-40 individuals. Achatinella sowerbyana, from the northern Ko’olau Mountains, is the next most abundant species with 1 to 20 snails per tree at the heart of its current range.