Physical Description

Type Information

Paratype for Helix repercussa Gould
Catalog Number: USNM 611236
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Preparation: Dry
Collector(s): J. Benjamin
Locality: Tavoy, Merqui, Burma
  • Paratype:
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Holotype for Glyphonyx helix Smith & Balsbaugh, 1984
Catalog Number: USNM
Collection: Smithsonian Institution, National Museum of Natural History, Department of Entomology
Sex/Stage: ; Adult
Preparation: Pinned
Year Collected: 1973
Locality: Raptides Parish La., Louisiana, United States
  • Holotype: Smith, J. W. & Balsbaugh. 1984. North Dakota Insects. 16 (1-5): 27.
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Holotype for Helix sportella Gould, 1846
Catalog Number: USNM 5442
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Preparation: Dry
Collector(s): C. Pickering
Locality: Oregon, United States, Puget Sound, North Pacific Ocean
  • Holotype: Proc. Boston Soc. nat. Hist. 2: 167.
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Holotype for Helix elliotti Redfield, 1856
Catalog Number: USNM 31286
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Preparation: Dry
Collector(s): J. Redfield
Locality: mountains, Georgia, United States
  • Holotype: Trans. Lyceum Nat. Hist. reprint p. 1.
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
The species is ecologically and biologically highly specialised and lives on and in the loose maritime sands of the river delta associated with low shrub vegetation (including Genista salzmannii) and with annual or biennial plants characteristic of coastal sands.

Systems
  • Terrestrial
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Habitat and Ecology

Habitat and Ecology
Moreletina obruta lives near the shore on sea cliffs; the white morph lives among gramineae, the black morph under stones. Although there are plenty of dead shells of the white morph, living specimens can be hard to find; the black morph is even rarer.

Systems
  • Terrestrial
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Depth range based on 1 specimen in 1 taxon.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 1 - 1
  Temperature range (°C): 19.373 - 19.373
  Nitrate (umol/L): 0.490 - 0.490
  Salinity (PPS): 38.902 - 38.902
  Oxygen (ml/l): 5.242 - 5.242
  Phosphate (umol/l): 0.159 - 0.159
  Silicate (umol/l): 1.547 - 1.547
 
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Depth range based on 1 specimen in 1 taxon.

Environmental ranges
  Depth range (m): 70 - 70
 
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Depth range based on 3 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 822 - 910

Graphical representation

Depth range (m): 822 - 910
 
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Depth range based on 19 specimens in 1 taxon.
Water temperature and chemistry ranges based on 3 samples.

Environmental ranges
  Depth range (m): 50 - 500
  Temperature range (°C): 16.934 - 18.458
  Nitrate (umol/L): 7.088 - 8.522
  Salinity (PPS): 35.428 - 35.451
  Oxygen (ml/l): 4.360 - 4.494
  Phosphate (umol/l): 0.282 - 0.460
  Silicate (umol/l): 4.194 - 4.413

Graphical representation

Depth range (m): 50 - 500

Temperature range (°C): 16.934 - 18.458

Nitrate (umol/L): 7.088 - 8.522

Salinity (PPS): 35.428 - 35.451

Oxygen (ml/l): 4.360 - 4.494

Phosphate (umol/l): 0.282 - 0.460

Silicate (umol/l): 4.194 - 4.413
 
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Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage

Barcode of Life Data Systems (BOLD) Stats
Specimen Records:65
Specimens with Sequences:59
Specimens with Barcodes:46
Species:11
Species With Barcodes:11
Public Records:46
Public Species:10
Public BINs:11
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Statistics of barcoding coverage: Decodes helix

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 7
Species With Barcodes: 1
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Barcode data

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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
CR
Critically Endangered

Red List Criteria
B1ab(i,ii,iii)+2ab(i,ii,iii)

Version
3.1

Year Assessed
2011

Assessor/s
Falkner, M., Falkner, G., von Proschwitz, T. & Charrier, M.

Reviewer/s
Cuttelod, A. & Bilz, M.

Contributor/s

Justification
This highly specialised species is a palaeoendemic of Corsica and the sole representative of the genus Tyrrhenaria worldwide. It is today restricted to a very narrow distribution area which is highly fragmented, suggesting a genetic impoverishment and unforeseeable events. Moreover, 40% of the population is located on a 0.0051 km area surrounded by the airport and the beach. These facts justify the maintenance of the species in the category Critically Endangered (CR B1ab(i,ii,iii)+2ab(i,ii,iii)).

History
  • 1996
    Critically Endangered (CR)
  • 1994
    Indeterminate (I)
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IUCN Red List Assessment


Red List Category
VU
Vulnerable

Red List Criteria
D2

Version
3.1

Year Assessed
2013

Assessor/s
Frias Martins, A.

Reviewer/s
Neubert, E., Cuttelod, A. & Nichols, C.

Contributor/s

Justification
Due to the highly restricted area and few number of sites where the specimens were found, it is clear that we are dealing with a small population; the disjunct distribution of the two morphs, which could well be two different species, enhances the fact that the diversity within the population is very much at risk due to isolation and small size. The fact that it was first found as a fossil but later found alive enhances the need for protection. This species is considered Vulnerable (VU D2) due to the combination of its small area of occupancy (Area of occupancy = 20 km2), its two unique locations and potential threats from accidental fire and natural events (such as cliff erosion).

History
  • 1996
    Vulnerable (VU)
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Population

Population
Thanks to human assistance and biotope management (Natura 2000 site) providing protected areas appropriate for snail colonization, the population is considered to be stable. The population size is estimated to be between 7,500 and 10,000 individuals among which 3,8005,200 are mature individuals (estimated information from samplings made in 20092010, M. Charrier, pers. comm., 2011)

Population Trend
Stable
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Population

Population
This species appears to have a disjunct distribution, the white ecomorph living in Figueiral (N 36 56.873'; W 25 07.715'; 100 m) and west of Praia Formosa (coordinate unavailable; 10 m); the black ecomorph was collected east of Anjos (coordinate unavilable; 50 m) and west of Anjos (N 37 00.481'; W 025 08.318'; 20 m) (Martins 2002)

Population Trend
Unknown
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Threats

Major Threats
The main threats to this species are urbanisation and land use around the town of Ajaccio, leading to habitat fragmentation and habitat loss, as well as leisure activities on the sand beach.
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Major Threats
As this species lives in cliff areas near the sea, only natural threats are foreseeable; however, accidental fires may pose a real threat to the white morph colonies, which live among gramineae.
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Management

Conservation Actions

Conservation Actions
This snail is legally protected at the national level in France ("Arrt du 23 avril 2007 fixant les listes des mollusques protgs sur l'ensemble du territoire et les modalits de leur protection (JORF nr. 106 du 6 mai 2007 page 8089, texte nr. 32)") and by the city of Ajaccio with "Convention avec le Conseil gnral de la Corse du Sud", a National Recovery Plan (NRP) obtained by Circulaires DEB/PEVM n08-07 du 3 octobre 2008 et n 09-04 du 8 septembre 2009, du Ministre de lEcologie, du Dveloppement Durable, des Transports et du Logement (MEDDMM) en faveur de lHlix de Corse, espce Grenelle . The NRP will outline actions for species protection beyond the context of the Natura 2000 programme (FR 9400619) that will extend the effort of habitat restoration.
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Conservation Actions

Conservation Actions
Due to their habitat (cliffs near the sea), only general preventive measures can be advised, such as preventing fires that could destroy the habitat. More taxonomic research is also needed on the two ecomorphs.
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Wikipedia

Helix engaddensis

Helix engaddensis is a species of snail common in the Levant, both in Mediterranean, desert and montane climates. It is smaller than the closely related European Garden snail and usually lighter in color. H. engaddensis goes through estivation. It is dormant in the ground during the dry season and emerges after the first rains (in late autumn). Mating takes place soon after emerging. The snails are active through winter (except in high montane regions, where they might be forced into a somewhat unnatural hibernation) and return to an inactive state at the end of the wet season (midspring).[1]

References[edit]


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Helix (gastropod)

Helix is a genus of large air-breathing land snails, terrestrial pulmonate gastropod molluscs. [2]

This genus is native to Europe and the regions around the Mediterranean Sea.

Helix is the type genus of the family Helicidae.

The best-known species include Helix aspersa, the common, or brown garden snail, and Helix pomatia, the Roman snail, Burgundy snail, or edible snail. H. pomatia and some other species are eaten as escargots.

Helix snails have been introduced throughout the world, where some, especially H. aspersa, have become garden pests.

The genus Helix is known from the Oligocene on.[3]

Snails in this genus create and use love darts during mating.

Species[edit]

Subgenera and species within the genus Helix include today:

Subgenus Helix

Subgenus Pelasga

Subgenus Cornu

  • Helix aspersa Müller, 1774 - brown garden snail or common garden snail also known as Cantareus aspersus and Cornu aspersum

Subgenus ?

Species brought into synonymy

Some taxonomists remove the species "Helix aperta", "Helix aspersa", and "Helix mazzullii" from the genus Helix and place them in their own monotypic genera as Cantareus apertus, Cornu aspersum[9] and Cantareus mazzullii.

At the beginning in the mid-1700s the generic name Helix had been used for almost all terrestrial gastropods, later this was restricted to species with helicoid habitus, including zonitids and other groups. In the course of the 1800s more groups were removed, but prior to 1900 several thousand helicid and hygromiid species of Europe and abroad had still been classified in the genus Helix.[10][11] It was only in the early 1900s that the genus was split up into many separate genera, leaving only some 30 species closely related to its type species Helix pomatia in the genus Helix.

External features[edit]

An unidentified Helix species from southern Europe

In addition to the hard calcareous shell that covers and protects the internal organs, the head and foot region can be observed when the snails are fully extended. When they are active, the organs such as the lung, heart, kidney and intestines remain inside the shell; only the head and foot emerge.

The head of the snail has two pairs of tentacles: the upper and larger pair contain the eyes, and the lower pair are used to feel the ground in front. The mouth is located just underneath the head. The tentacles can be withdrawn or extended depending on the situation. The mouth has a tongue called a "radula" that is composed of many fine chitinous teeth. This serves for rasping and cutting food.

Behaviour[edit]

From April through the northern summer, the number of snails copulating increases due to the higher temperature and humidity, which enhance the possibility of oviposition. The pulmonate snails are hermaphroditic, meaning that both female and male sexual organs are present in the same individual. The snails produce both eggs and sperm in the ovotestis (also called the hermaphrodite gland), but it is later separated into two divisions, a sperm duct and oviduct, respectively.

Mating takes several hours, sometimes a day. H. aspersa snails stab a calcite spine, known as a "love dart", at their partner. The love dart is coated with a mucus that contains a chemical that enables more than twice as many sperm to survive inside the recipient. A few days after mating, the eggs are laid in the soil. The eggs are usually 4–6 mm in diameter.

After snails hatch from the egg, they mature in one or more years, depending on where the organism lives. Maturity takes two years in Southern California, while it takes only ten months in South Africa.

The size of the adult snails slightly varies with species. H. aspersa grows up to 35 mm in height and width, whereas H. pomatia grows up to 45 mm. The life span of snails in the wild is on average two or three years.

Some snails may live longer, perhaps even 30 years or older in the case of the Roman snail[12] but most live less than 8 years. Many deaths are due to predators and parasites.

The garden snail is a relatively fast snail. It has been observed to reach speeds of up to 1.3 cm/s.[13]

Respiration[edit]

Since snails in the genus Helix are terrestrial rather than fresh-water or marine, they have developed a simple lung for respiration. (Most other snails and gastropods have gills,instead.)

Oxygen is carried by the blood pigment hemocyanin. Both oxygen and carbon dioxide diffuse in and out of blood through the capillaries. A muscular valve regulates the process of opening and closing the entrance of the lung. When the valve opens, the air can either leave or come into the lung. The valve plays an important role in reducing water loss and preventing drowning.

Ecology[edit]

Helix snails prefer cool, damp environments, as they easily suffer moisture loss. Snails are most active at night and after rainfall. During unfavourable conditions, a snail will remain inside its shell, usually under rocks or other hiding places, to avoid being discovered by predators. In dry climates snails will naturally congregate near water sources, including artificial sources such as waste-water outlets of air conditioners.

The common garden snail (Helix aspersa) is herbivorous. These snails are able to digest most vegetation including carrots and lettuce. They also have a specialized crop of symbiotic bacteria that aid in their digestion, especially with the breakdown of the polysaccharide cellulose into simple sugars.

Many predators, both specialist and generalist, feed on snails. Some animals, such as the song thrush, break the shell of the snail by hammering it against a hard object, such as stone, in order to expose its edible insides. Other predators, such as some species of frogs, circumvent the need to break snail shells by simply swallowing the snail whole, shell and all.

Some carnivorous species of snails, such as the decollate snail and the rosy wolf snail, also prey on Helix snails. Such carnivorous snails are commercially grown and sold in order to combat pest snail species. Many of these also escape into the wild, where they prey on indigenous snails, such as the Cuban land snails of the genus Polymita, and the indigenous snails of Hawaii.

Edible snails[edit]

H. pomatia and H. aspersa are the two edible species that are most used in European cuisine. Spanish cuisine also uses Otala punctata, Theba pisana and Iberus gualterianus alonensis, amongst others. The process of snail farming is called heliciculture.

Escargots are often served in a traditional way as appetizers. They may also be used as ingredients in other recipes.

Snails contain many nutrients. They are rich in calcium and also contain vitamin B1 and E. They contain various essential amino acids, and are low in calories and fat.

References[edit]

  1. ^ Genus taxon summary for Cantareus. AnimalBase, Last modified 14-11-2006 by F. Welter Schultes, accessed 1 April 2009.
  2. ^ Rosenberg, G.; Bouchet, P. (2014). Helix Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153970 on 2015-02-24
  3. ^ Ivanov M., Hrdličková, S. & Gregorová, R. (2001) Encyklopedie zkamenělin. – Rebo Productions, Dobřejovice, 1. vydání, 312 pp., page 126. (in Czech)
  4. ^ Sysoev, A. & Schileyko, A. 2009. Land snails and slugs of Russia and adjacent countries. - pp. 1-312, Fig. 1-142. Sofia. (Pensoft).
  5. ^ Mumladze L., Tarkhnishvili D. & Pokryszko B.M. 2008. A new species of the genus Helix from the Lesser Caucasus (sw Georgia). Journal of Conchology, volume: 39, part 5, page 483, published June 2008. abstract
  6. ^ Mylonas, M. 1996. Helix godetiana. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 2 April 2007. http://www.iucnredlist.org/search/details.php/9844/summ
  7. ^ Frias-Martin, A. 1996. Helix obruta. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 2 April 2007. http://www.iucnredlist.org/search/details.php/9845/summ
  8. ^ Heller, J. 1996. Helix texta. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 2 April 2007. http://www.iucnredlist.org/search/details.php/9846/summ
  9. ^ The Cornu Problem
  10. ^ Westerlund, C. A. 1889. Fauna der in der paläarctischen Region (Europa, Kaukasien, Sibirien, Turan, Persien, Kurdistan, Armenien, Mesopotamien, Kleinasien, Syrien, Arabien, Egypten, Tripolis, Tunesien, Algerien und Marocco) lebenden Binnenconchylien. II. Gen. Helix. - pp. 1-473, 1-31, 1-8. Berlin. (Friedländer).
  11. ^ Pfeiffer, L. & Clessin, S. 1881. Nomenclator heliceorum viventium quo continetur nomina omnium hujus familiae generum et specierum hodie cognitarum, disposita ex affinitate naturali. - pp. 1-617. Cassellis. (Fischer).
  12. ^ The Roman Snail, Helix pomatia
  13. ^ Yee, Angie (1999). "Speed of a Snail". The Physics Factbook. 
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Tyrrhenaria ceratina

Tyrrhenaria ceratina is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is endemic to Corsica.

References[edit]

  1. ^ Falkner, M., Falkner, G., von Proschwitz, T. & Charrier, M. (2011). "Tyrrhenaria ceratina". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 19 February 2014. 
  2. ^ (German) Shuttleworth R. J. 1843. Über die Land- und Süsswasser-Mollusken von Corsica. Mittheilungen der Naturforschenden Gesellschaft in Bern 1843 (2/3): 9-21.
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Helix obruta

Helix obruta is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is endemic to Portugal.

References

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Calliotropis helix

Calliotropis helix is a species of sea snail, a marine gastropod mollusk in the family Calliotropidae.[1]

Contents

Description

The length of the shell reaches 20 mm.

Distribution

This marine species occurs off Taiwan and in the South China Sea.

References

  1. ^ Calliotropis helix Vilvens, 2007.  Retrieved through: World Register of Marine Species on 18 April 2010.
  • Vilvens C. (2007) New records and new species of Calliotropis from Indo-Pacific. Novapex 8 (Hors Série 5): 1-72
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