Lanistes
Encyclopedia
Lanistes is a genus
of freshwater snail
s which have a gill
and an operculum
, aquatic
gastropod mollusks in the family Ampullariidae
, the apple snails.
. This means that the body of the snail is dextral (as in all other ampullariids), but the shell appears to be sinistral. However the sinistral appearance stems from the fact that the rotation of the shell as it grows is in an upward direction rather than the usual downward direction.
differences: Lanistes sensu stricto, Meladomus and Leroya. These subgenera are not used in recent works.
Extant species within the genus Lanistes include:
Fossil species within the genus Lanistes include:
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
s which have 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...
, aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
gastropod mollusks in the family Ampullariidae
Ampullariidae
Ampullariidae, common name the apple snails, is a family of large freshwater snails, aquatic gastropod mollusks with a gill and an operculum...
, the apple snails.
Distribution
The distribution of the genus Lanistes includes Africa and Madagascar.Description
Lanistes has a unique anatomy among the Ampullariidae: it has a "hyperstrophic" sinistral 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...
. This means that the body of the snail is dextral (as in all other ampullariids), but the shell appears to be sinistral. However the sinistral appearance stems from the fact that the rotation of the shell as it grows is in an upward direction rather than the usual downward direction.
Species
Three subgenera have been recognized, based on 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...
differences: Lanistes sensu stricto, Meladomus and Leroya. These subgenera are not used in recent works.
Extant species within the genus Lanistes include:
- Lanistes alexandriLanistes alexandriLanistes alexandri is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.This species is endemic to Tanzania.- References :*...
(Bourguignat, 1889) - Lanistes bicarinatusLanistes bicarinatusLanistes bicarinatus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.This species is endemic to the Democratic Republic of the Congo....
Germain, 1907 - Lanistes carinatus (Olivier, 1804) - type species
- Lanistes ciliatusLanistes ciliatusLanistes ciliatus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to Kenya....
Martens, 1878 - Lanistes congicus O. Boettger, 1891
- Lanistes ellipticus Martens, 1866
- Lanistes farleriLanistes farleriLanistes farleri is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to Tanzania....
Craven, 1880 - Lanistes grasseti (Morelet, 1863)
- Lanistes graueriLanistes graueriLanistes graueri is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to the Democratic Republic of the Congo....
Thiele, 1911 - Lanistes intortusLanistes intortusLanistes intortus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to the Democratic Republic of the Congo...
Martens, 1877 - Lanistes libycus (Morelet, 1848)
- Lanistes libycus var. albersi
- Lanistes libycus form bernardianus or as Lanistes bernardianus (Morelet, 1860)
- Lanistes nasutusLanistes nasutusLanistes nasutus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is found in Malawi and Mozambique....
Mandahl-Barth, 1972 - Lanistes neaveiLanistes neaveiLanistes neavei is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is found in the Democratic Republic of the Congo and Zambia....
Melvill & Standen, 1907 - Lanistes neritoidesLanistes neritoidesLanistes neritoides is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to the Republic of the Congo....
Brown & Berthold, 1990 - Lanistes nsendweensis (Dupuis & Putzeys, 1901)
- Lanistes nyassanus Dohrn, 1865
- Lanistes ovumLanistes ovumLanistes ovum is a species of freshwater snail with an operculum, an African apple snail, an aquatic gastropod mollusk in the family Ampullariidae....
Peters in Troschel, 1845 - synonyms: Lanistes magnus Furtado; Lanistes olivaceus (Sowerby); Lanistes procerus; Lanistes elatior Martens, 1866; Lanistes ovum bangweolicus Haas, 1936; Lanistes connollyi Pain, 1954 Lanistes ovum adansoni; Lanistes olivaceus var. ambiguus - Lanistes pseudoceratodes (Wenz, 1928)
- Lanistes purpureus (Jonas, 1839)
- Lanistes solidusLanistes solidusLanistes solidus is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.- Distribution :It is found in Malawi and Mozambique....
Smith, 1877 - Lanistes stuhlmanniLanistes stuhlmanniLanistes stuhlmanni is a species of large freshwater snail, an aquatic gastropod mollusk with a gill and an operculum in the family Ampullariidae, the apple snails.It is endemic to Tanzania....
Martens, 1897 - Lanistes varicus (Müller, 1774) - synonyms: Lanistes adansoni Kobelt, 1911; Lanistes millestriatus Pilsbry & Bequaert, 1927
Fossil species within the genus Lanistes include:
- † Lanistes asellus van Damme & Pickford, 1995
- † Lanistes bishopi Gautier
- † Lanistes gautieri van Damme & Pickford, 1995
- † Lanistes gigas van Damme & Pickford, 1995
- † Lanistes hadotoi van Damme & Pickford, 1995
- † Lanistes heynderycxi van Damme & Pickford, 1995
- † Lanistes nkondoensis van Damme & Pickford, 1995
- † Lanistes olukaensis
- † Lanistes senuti van Damme & Pickford, 1995
- † Lanistes trochiformis van Damme & Pickford, 1995
External links
- Animation showing how the "hyperstrophic" sinistral shell evolved from a shell with normal orientation
- Schultheiß R., Van Bocxlaer B., Wilke T. & Albrecht C. (2009). "Old fossils–young species: evolutionary history of an endemic gastropod assemblage in Lake Malawi". Proceedings of the Royal Society B 276(1668): 2837-2846. doi:10.1098/rspb.2009.0467.