Amphicyclotulus amethystinus
Encyclopedia
Amphicyclotulus amethystinus is a species
of tropical land snail
with a gill
and an operculum
, a terrestrial
gastropod mollusk in the family Neocyclotidae
.
is smooth, shining, not striate spirally, generally somewhat more depressed, deep chestnut or reddish brown. Whorls
are a little flattened near the suture. The species may have subtle spiral striation, although there exists considerable variation; axial growth lines are clearly visible.
The operculum
is horny, diaphanous, concave externally, cartilaginous within, the nucleus projecting internally; with from ten to fourteen very narrow whorls, their rather lamellar outer edges slightly free.
Amphicyclotulus amethystinus has spiral threads absent or only weakly present. There are found only two species in the genus Amphicyclotulus in Dominica. The other species is Amphicyclotulus dominicensis
and it has spiral cords clearly present and raised.
Robert John Lechmere Guppy
(1868) noted that this species is not found above 1000 m. Although he recognized two “forms”, he did not recognize two separate species. George French Angas
(1884) subsequently recorded “Cyclophorus amethystinus” from altitudes above 1200 m. Paul Bartsch
(1942) restricted the name amesthystinus to Guppy’s var. β, the “smooth, shining, not striate spirally” form.
The type locality is Laudat
, Dominica. The holotype
is in National Museum of Natural History
under number 535856.
All known localities of Amphicyclotulus amethystinus include:
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of tropical land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
with a gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
and an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
gastropod mollusk in the family Neocyclotidae
Neocyclotidae
Neocyclotidae is a family of tropical land snails with gills and an operculum, terrestrial gastropod mollusks in the informal group Architaenioglossa belonging to the clade Caenogastropoda .-Subfamilies:Subfamilies within the family Neocyclotidae include:* subfamily Neocyclotinae Kobelt &...
.
Shell description
The shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is smooth, shining, not striate spirally, generally somewhat more depressed, deep chestnut or reddish brown. Whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
are a little flattened near the suture. The species may have subtle spiral striation, although there exists considerable variation; axial growth lines are clearly visible.
The operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
is horny, diaphanous, concave externally, cartilaginous within, the nucleus projecting internally; with from ten to fourteen very narrow whorls, their rather lamellar outer edges slightly free.
Amphicyclotulus amethystinus has spiral threads absent or only weakly present. There are found only two species in the genus Amphicyclotulus in Dominica. The other species is Amphicyclotulus dominicensis
Amphicyclotulus dominicensis
Amphicyclotulus dominicensis is a species of tropical land snail with a gill and an operculum, a terrestrial gastropod mollusk in the family Neocyclotidae.-Distribution:This species is endemic to the West Indian island of Dominica....
and it has spiral cords clearly present and raised.
Robert John Lechmere Guppy
Robert John Lechmere Guppy
Robert John Lechmere Guppy was a British-born naturalist after whom the guppy is named...
(1868) noted that this species is not found above 1000 m. Although he recognized two “forms”, he did not recognize two separate species. George French Angas
George French Angas
George French Angas , was an English explorer, naturalist and painter.He was born in Newcastle upon Tyne, England, the eldest son of George Fife Angas, prominent in the establishment of the new colony of South Australia. Despite showing remarkable talent in drawing, he was placed in a London...
(1884) subsequently recorded “Cyclophorus amethystinus” from altitudes above 1200 m. Paul Bartsch
Paul Bartsch
Paul Bartsch was an American malacologist and carcinologist.Paul Bartsch emigrated to the U.S.A in 1880. He graduated from the University of Iowa with a B.S. in 1896, and M.S. in 1899, and PhD in 1905...
(1942) restricted the name amesthystinus to Guppy’s var. β, the “smooth, shining, not striate spirally” form.
Distribution
This species is endemic to in Dominica.The type locality is Laudat
Laudat
Laudat is a small village in the interior of Dominica, nestled between 3 mountains: Morne Watt, Morne Micotrine , and Morne Trois Pitons...
, Dominica. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
is in National Museum of Natural History
National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. Admission is free and the museum is open 364 days a year....
under number 535856.
All known localities of Amphicyclotulus amethystinus include:
- Saint Andrew Parish, DominicaSaint Andrew Parish, DominicaSaint Andrew is one of Dominica's 10 administrative parishes. It is bordered by St. John and St. Peter , St. Joseph , and St. David ....
: west of CalibishieCalibishieCalibishie is a town in Dominica. It is located on the north coast of the island, immediately to the east of the village of Hampstead. The Calibishie Coast Travel Area is thought by many to be the most scenic and unspoiled region of Dominica...
, Hampstead Estate - Saint Andrew Parish, Dominica: Carib TerritoryCarib TerritoryThe Carib Territory or Carib Reserve is a district in the Caribbean island-nation of Dominica. It was established for the descendants of the indigenous Carib people, also known as the Kalinago, who inhabited Dominica prior to European colonization and settlement.The Carib Territory was officially...
- Saint Andrew Parish, Dominica: MarigotMarigotThe French name Marigot is given to several places in the Caribbean:*Marigot, Dominica, a village in Dominica*Marigot, Saint Martin, the largest settlement on the French side of Saint Martin *Marigot, Saint Barthélemy*Marigot Bay, Saint Lucia...
, Captain Bruce - Saint Andrew Parish, Dominica: 1 km northwest of Thibaud
- Saint David Parish, DominicaSaint David Parish, DominicaSaint David is one of Dominica's ten administrative parishes, located on the eastern side of the island. It is bordered by St. Andrew to the north; St. Joseph, St. Paul and St. George to the west; and St. Patrick to the south. It has an area of 131.6 km² , and has a population of...
: Emerald PoolEmerald PoolEmerald Pool is the name of several locations.-Yosemite:Emerald Pool is a small, shallow lake located immediately above Vernal Fall in Yosemite National Park. It is named for its deep green color, which is caused by algae living on the rocks at the bottom of the pool... - Saint David Parish, Dominica: 1.5 km north of Petit Savane
- 0.5 km south of Rosalie River bridge
- Saint George Parish, DominicaSaint George Parish, DominicaSaint George is one of Dominica's 10 administrative parishes. It is bordered by Saint Paul and part of the Boeri River , Saint Patrick , and Saint Luke ....
: Bellevue Chopin - Saint George Parish, Dominica: Freshwater Lake area
- Saint George Parish, Dominica: trail to Lake Boeri
- Saint Joseph Parish, DominicaSaint Joseph Parish, DominicaSaint Joseph is one of Dominica's 10 administrative parishes. It is bordered by St. Peter to the north, St. Andrew to the northeast, St. David to the east, and St. Paul to the south. It has an area of 120.1 km² , and a population of 5,765....
: d’Leau Grommier - Saint Joseph Parish, Dominica: road to Fond Cassé, Mary Martin Farm
- Saint Joseph Parish, Dominica: path Mero-SalisburySalisburySalisbury is a cathedral city in Wiltshire, England and the only city in the county. It is the second largest settlement in the county...
- Saint Luke Parish, DominicaSaint Luke Parish, DominicaSaint Luke is one of Dominica's 10 administrative parishes. It is bordered by St. George , St. Mark , and St. Patrick ....
: Pointe MichelPointe MichelPointe Michel is a small town on the southwest coast of Dominica. It is located to the south of the capital, Roseau, and is known for being the birthplace of Dominica's first female Prime Minister, Dame Eugenia Charles.... - Saint Paul Parish, DominicaSaint Paul Parish, DominicaSaint Paul is one of Dominica's 10 administrative parishes. It is bordered by St. Joseph to the north, St. David to the east, and St. George to the south. It has an area of 67.4 km² , and a population of 8,397....
: SylvaniaSylvaniaSylvania literally means "forest land" in Latin. The term can be used in a variety of contexts:- Companies :*Sylvania , a brand of consumer electronics sold by Funai which include popular items such as the & the .... - Saint Peter Parish, DominicaSaint Peter Parish, DominicaSaint Peter is one of Dominica's 10 administrative parishes. It is bordered by St. John to the north, St. Joseph to the south, and St. Andrew to the east. It has an area of 27.7 km² , and has a population of 1,452. Colihaut , Dublanc and Bioche are its only settlements....
: Syndicate.