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Giant Land Snail


Giant Land Snail
Photo Information
Copyright: Steve Reekie (LordPotty) Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1449 W: 146 N: 3764] (12035)
Genre: Animals
Medium: Color
Date Taken: 2009-01-22
Categories: Molluscs
Camera: Panasonic Lumix DMC-FZ8
Exposure: f/2.8, 1/50 seconds
More Photo Info: [view]
Photo Version: Original Version
Date Submitted: 2009-02-19 12:26
Viewed: 1014
Points: 20
[Note Guidelines] Photographer's Note
Powelliphanta

Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Orthogastropoda
Superorder: Heterobranchia
Order: Pulmonata
Suborder: Eupulmonata
Family: Rhytididae
Genus: Powelliphanta

Powelliphanta, common name amber snails, is a genus of large, carnivorous land snails, terrestrial pulmonate gastropod molluscs. As a group their survival status is endangered.

There are 21 species and 51 subspecies within the
genus. The relationship between the species is complex, and it has been suggested that the group
Powelliphanta gilliesi-traversi-hochstetteri-rossiana-lignaria-superba forms a ring species.
In November 2003 a subspecies, thought to be extinct, was rediscovered alive on the West Coast; it had last been documented on the basis of shell fragments in 1934.

Distribution:
These large snails are endemic to New Zealand, in small areas of the North and South Islands, with the greatest diversity of species in the mountains of northwest Nelson in the South Island.

Habitat:
These snails live mostly in tiny pockets of moist native bush.

Shell description:
These gastropods are large, with shells up to 9 cm across (Powelliphanta superba prouseorum).
Their striking delicately-patterned shells come in an array of shades, from brown or red to yellow or black. The structure of these shells is very delicate, with a very thin layer of calcium carbonate, covered by a thicker chitinous outer layer. These snails need moist surroundings, otherwise the outer layer (periostracum) dries, shrinks and cracks. This happens often in museum shells of this genus which are stored dry; when they dry too much, the shell shatters explosively into fairly small pieces.

Life habits:
Species in the genus Powelliphanta are carnivorous and eat mostly earthworms or slugs. They are nocturnal. They need moist surroundings and thus they live buried under leaf mould and logs.
They can live for 20 years or more and are slow to mature, reaching sexual maturity around 5 years of age. They are hermaphrodites, having both male and female characteristics. They lay 5 to 10 large eggs a year.

Fossil record:
Their origin goes back 200 million years to the continent Gondwana. Through their isolation in New Zealand, they have evolved a unique set of characteristics. They are a clear demonstration of New Zealand’s unique biodiversity.

Human use:
An unspecified species of Powelliphanta recently appeared on a New Zealand 40-cent postage stamp.

Conservation status:
The IUCN Red List states for Powelliphanta marchantii a lower risk, near threatened. But most of these snails are under serious threat or even in danger of extinction. They have no defense against introduced predators, such as common brushtail possums, Trichosurus vulpecula, and rats. Many recovery plans are being launched by the New Zealand Department of Conservation. The subspecies Powelliphanta gilliesi brunnea and Powelliphanta traversi otakia are the most threatened.


I found this rare snail shell at about 1200 metres above sea level, on top of Mt Ryall, alongside the Croesus Track.
Sinc it was some distance from any bush,I guessed it must have been carried there by a bird.

I hope you like this shot of our giant land snail, Powelliphanta.

Thanks for looking,
Cheers
Steve
boreocypriensis, matatur, eqshannon, haraprasan, ferranjlloret, gannu has marked this note useful
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Critiques [Translate]

Ciao Steve, fantastic light on beautiful snail with fine details, splendid sharpness and wonderful colors in BG, very well done, ciao Silvio

Hi Steve,
A fine macro capture of a giant land snail from nice pov with excellent details, sharpness and great composition. The colours of the surrounding bg ar also wonderful.
TFS and cheers,
Bayram

A beautifully executed capture of a rare shell probably broken by a bird's beak Steve, it displays its fine colour tones in spite of the reflections, and the contrast provided bt the BG is so nice to behold. TFS this fine image and the notes my friend.
Cheers, Mehmet

For some reason the yellow gives the shell much more of a gaze effect..I wonder if it is just me that notices...I have not read others yet...and due to the crack, it brings back some memories of the smell...I have had similar in hand...Very nice notes to go with your imagery S!
Bob

  • Great 
  • zetu Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 649 W: 15 N: 1607] (6263)
  • [2009-02-20 0:25]

Hello Steve
Nice and interesting capture with beautiful colors.
Regards.
Razvan

Namastay Steve,
A nice capture of this beautiful large snail. Superb sharp details and a lovely composition. Thanks a lot for sharing.

Sincerely
Hara

Hello Steve,
Splendid colours in this photo. Great choice of POV and composition.
Best Regards,
Ferran

  • Great 
  • foozi Gold Star Critiquer/Gold Note Writer [C: 1339 W: 0 N: 2575] (9085)
  • [2009-02-21 20:11]

Hi Steve,
very sharp and clear coiling effects. the BG makes this one so discerned and lovely.
The view explains its features and the damaged part give the knowledge of the interior.
Well presented and a special shot.

Regards,
Foozi

  • Great 
  • gannu Gold Star Critiquer/Gold Note Writer [C: 1169 W: 4 N: 3262] (14691)
  • [2009-02-22 8:51]

Steve, Very nice capture of this snail and a nice one. This is now 5-6 of its kind in TN. Well done Ganesh

nice-shiny one, TFS Ori

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