Wainuia urnula
| Wainuia urnula | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Wainuia urnula | ||||||||||||
| ( Pfeiffer , 1855) |
Wainuia urnula is the name of a predatory living snail from the family Rhytididae in the subordination of terrestrial snails (gastropod), which in New Zealand is spread on both main islands. A special feature is that it primarilyeatsvery mobile land-living amphipods .
features
Wainuia urnula has a half-covered, pierced, flattened, flat wrinkled, thin and transparent, wrinkled, slightly silky, shiny and light greenish horn-colored snail shell with a very short, conical thread. The house of the lively, even very dark snail is reddish brown or dark brown to almost black. The house of the adult snail has three and a half moderately arched and very rapidly increasing coils with a deep seam, the last being large and greatly broadened towards the front. The very oblique and obliquely oval case mouth is moderately cut out. The straight edge of the mouth, the edges of which are very close, is covered by the inflected periostracum . The edge of the spindle is turned up triangular at the top. The case has a diameter of 16 and 12.3 mm and a height of 10.3 mm. Only the top two turns of the shell contain a layer of lime, while the rest consists entirely of conchin . As with other members of the genera Wainuia , Rhytida and Schizoglossa, the radula has only a few teeth per row compared to the other species in the family.
Distribution and occurrence
Wainuia urnula is endemic to the North Island of New Zealand near Wellington in pristine forests in Hutt Valley , Wainuiomata , Eastbourne , Remutaka Range , Tararua Range , Ruahine Range north to No Man's Hut and in a small area across the Cook Strait on the opposite side of the South Island in Port Underwood Saddle , occasionally in Richmond Range , at Flaxbourne near Ward , Isolated Hill , Ben More , at Kekerengu , in Wharekupenga Bay , Arapawa Island and on D'Urville Island ( Mount Maude ). The subspecies Wainuia urnula urnula found the North Island under loose, moist on the leaf litter and rock dumps both in intact and in highly degenerate forests of various types with Nothofagus menziesii , Nothofagus truncata , Dacrydium cupressinum , Metrosideros robusta , Kunzea ericoides and Elaeocarpus gyrus , under rotting fern fronds of Cyathea dealbata (but not Cyathea medullaris ) and Dicksonia squarrosa , but also under Blechnum discolor and rarely under Blechnum capense , around tufts of Uncinia spp. as well as in subalpine grasslands ( Tussock ) under Chionochloa spp. The subspecies Wainuia urnula nasuta lives in the South Island and D'Urville Iceland in moist leaf litter in forests with Weinmannia racemosa under Uncinia sp., In rock piles and between rocks in Lower mixed forest with melicytus ramiflorus , Fuchsia excorticata , Toronia toru , Weinmannia racemosa and Olearia spp .
Life cycle
Like other lung snails, Wainuia urnula is also a hermaphrodite , in which the partners exchange their sperm during mating. Soon afterwards, both partners lay 2 to 5 white, oval eggs with a chalky shell in leaf litter , which are usually around 5 mm (4.5 mm to 5.25 mm) long and 4 mm (3.75 mm to 4.25 mm) wide are.
nutrition
Like other species in the genus, Wainuia urnula is nocturnal. Preferred prey of Wainuia urnula are terrestrial flea crabs (Amphipoda) that using the pre-stretched Odontophore taken with the Radulazähnen and be conveyed into the mouth of the screw. The prey is recognized with the eyes at a distance of 5 to 10 mm. Escape is more likely for the prey if its distance from the snail's mouth is more than 5 mm at the moment the tongue pops out. The most common species of amphipod in the area and thus the main prey is Parorchestia tenuis . In one count, remains of flea shrimp were found in 82 percent of 315 snails examined, while remains of the second most common prey, earthworms , were found in only 4 percent of the snails. This is where Wainuia urnula differs from Wainuia edwardi and Wainuia clarki , which mainly eat earthworms.
Predators and threats
Important predators are imported climbing sacs ( Trichosurus vulpecula ), rats ( Rattus spp.), Pigs ( Sus scrofa ) and hedgehogs ( Erinaceus europaeus ), which also eat adult snails. The eggs are eaten by the predatory snail Delos coresia Gray (Rhytididae) , among others . Introduced pigs and deer contribute to the destruction of the forests, which is considered to be the greatest threat to snails, through their browsing and representation . The subspecies Wainuia urnula urnula on the North Island reacts rather robustly to the degradation of the habitats, while on the South Island and D'Urville Island the subspecies Wainuia urnula nasuta has decreased significantly due to the destruction of the habitat.
Web links
- Murray Efford: Distribution and status of native carnivorous land snails in the genera Wainuia and Rhytida. ( 5th chapter , appendix )
Individual evidence
- ↑ a b O. von Möllendorff: Agnatha Moerch. Predator snails. 2. Genus Paryphanta Alb. , 5. Paryphanta urnula, pp. 13f. In: O. von Moellendorff and Wilhelm Kobelt: Die Raublungenschnecken (Agnatha). Systematic Conchylia Cabinet by Martini and Chemnitz. Verlag von Bauer and Raspe (Emil Küster), Nuremberg 1905.
- ↑ Murray Efford: Distribution and status of native carnivorous country snails in the genera Wainuia and Rhytida. P. 6, 7 and 28. )
- ^ 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. 51–53.
- ↑ Murray Efford: Distribution and status of native carnivorous country snails in the genera Wainuia and Rhytida. Pp. 28-31.
- ^ 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.
- ↑ a b Murray Efford: Consumption of amphipods by the New Zealand snail. Wainuia urnula (Pulmonata: Rhytididae). ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Journal of Molluscan Studies 66, pp. 45-52. London 2000.
