Powelliphanta lignaria
| Powelliphanta lignaria | ||||||||||||
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Powelliphanta lignaria ssp. johnstoni , Charming Creek, Buller District |
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| Scientific name | ||||||||||||
| Powelliphanta lignaria | ||||||||||||
| ( Hutton , 1888) |
Powelliphanta lignaria is the name of a predatory living snail from the family Rhytididae in the subordination of terrestrial snails (gastropod), which in New Zealand is widespread.
features
The surface of the bifurcated, moderately large snail shell of Powelliphanta lignaria has a microscopic dorsal sculpture with narrow spiral stripes and typically radial bands with alternating yellowish and dark reddish brown stripes. In some individuals the brown bands are quite broad, but the yellowish ones are always invariably narrow. In addition, there are several more powerful, flat spiral furrows towards the upper seam. The house of the adult snail, including the protoconch, has five to five and a half whorls. The diameter of the house in animals from St. Helens are 48 mm to 59 mm and 39.5 mm to 49.5 mm, the height around 27 mm to 34 mm. The tooth formula of the radula is 70 + 1 + 70. The central tooth is the same size as the adjacent lateral teeth. The individual teeth are similar to those of Powelliphanta hochstetteri .
Distribution and occurrence
Powelliphanta lignaria is endemic to an area on the west coast of New Zealand's South Island in the north west country between the Heaphy and Mokihinui Rivers . It lives under leaf litter and dead wood in the dense rainforest of the lowlands with Nothofagus spp. and Metrosideros robusta , Dacrydium cupressinum , Ripogonum scandens and Freycinetia banksii .
Life cycle
Like other species of the genus Powelliphanta , Powelliphanta lignaria is long-lived and lays only a few eggs after mutual fertilization of the hermaphrodites , which are about 9 mm to 10 mm long and 8 mm wide.
nutrition
The main food of Powelliphanta snails are earthworms .
Predators and threats
The main threat to Powelliphanta lignaria are entrained predatory mammals , particularly rats and Kletterbeutler ( Trichosurus vulpecula ), as well as song thrushes . In addition, almost half of the forest was cut down at the beginning of the 20th century, but large parts of it were able to regenerate. About 5% to 10% of the area has been turned into grazing land.
Subspecies
There are seven subspecies of Powelliphanta lignaria . All are classified as threatened by the New Zealand Department of Conservation:
- Powelliphanta lignaria johnstoni Powell , 1946 - Nationally Endangered
- Powelliphanta lignaria lignaria Hutton , 1888 - Nationally Vulnerable
- Powelliphanta lignaria lusca Powell, 1949 - Nationally Vulnerable
- Powelliphanta lignaria oconnori Powell, 1938 - Nationally Vulnerable
- Powelliphanta lignaria rotella Powell, 1938 - Nationally Endangered
- Powelliphanta lignaria ruforadiata Powell, 1949 - Nationally Endangered
- Powelliphanta lignaria unicolorata Powell, 1930 - Nationally Vulnerable
Web links
Individual evidence
- ^ Arthur William Baden Powell (1930): The Paryphantidae of New Zealand: their Hypothetical Ancestry, with descriptions of New Species and a New Genus. Records of the Auckland Institute and Museum 1 (1), pp. 17–56, here pp. 42f.
- ↑ a b Kath Walker: Recovery plans for Powelliphanta land snails 2003-2013. Threatened Species Recovery Plan 49, 3. The recovery plans. Pp. 111-129.
- ^ AC O'Connor (1945): Notes on the Eggs of New Zealand Paryphantidae, With Description of a New Subgenus. Transactions of the Royal Society of New Zealand 5 (1945-1946), pp. 54-57.
- ↑ New Zealand snails: Powelliphanta Department of Conservation / Te Papa Atawhai, Christchurch of 2006.
- ^ Arthur William Baden Powell : New Zealand Mollusca . William Collins Publishers Ltd., Auckland 1979. ISBN 0-00-216906-1
- ^ New Zealand Threat Classification System lists - 2002 - Terrestial (sic) invertebrate - part one. New Zealand Department of Conservation, 2002.