Lanistes

Lanistes
Drawing of an apertural view of the shell of Lanistes ovum
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Caenogastropoda informal group Architaenioglossa
Superfamily:	Ampullarioidea
Family:	Ampullariidae
Subfamily:	Ampullariinae
Tribe:	Ampullariini
Genus:	Lanistes Montfort, 1810[1]
Diversity
21 extant species[2][3] and at least 10 fossil species[4]
Synonyms
former subgenera: Meladomus Swainson, 1840[5] Leroya Grandidier, 1887[6]

Lanistes is a genus of freshwater snails which have a gill and an operculum, aquatic gastropod mollusks in the family Ampullariidae, the apple snails.

Distribution

The distribution of the genus Lanistes includes Africa and Madagascar.^[3]

Description

Lanistes has a unique anatomy among the Ampullariidae: it has a "hyperstrophic" sinistral shell.^[7] This means that the body of the snail is dextral (as in all other ampullariids), but the shell appears to be sinistral.^[7] 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.^[7]

Species

Three^[3] subgenera have been recognized, based on shell differences: Lanistes sensu stricto, Meladomus and Leroya. These subgenera are not used in recent works.^[3]

Extant species within the genus Lanistes include:

• Lanistes alexandri (Bourguignat, 1889)^[3]
• Lanistes bicarinatus Germain, 1907^[3]
• Lanistes carinatus (Olivier, 1804) - type species^[2][3]
• Lanistes ciliatus Martens, 1878^[2][3]
• Lanistes congicus O. Boettger, 1891^[2][3]
• Lanistes ellipticus Martens, 1866^[2][3]
• Lanistes farleri Craven, 1880^[2][3]
• Lanistes grasseti (Morelet, 1863)^[3]
• Lanistes graueri Thiele, 1911^[2][3]
• Lanistes intortus Martens, 1877^[2][3]
• Lanistes libycus (Morelet, 1848)^[2][3]
  • Lanistes libycus var. albersi
  • Lanistes libycus form bernardianus^[3] or as Lanistes bernardianus (Morelet, 1860)^[2]
• Lanistes nasutus Mandahl-Barth, 1972^[2][3]
• Lanistes neavei Melvill & Standen, 1907^[2][3]
• Lanistes neritoides Brown & Berthold, 1990^[2][3]
• Lanistes nsendweensis (Dupuis & Putzeys, 1901)^[3]
• Lanistes nyassanus Dohrn, 1865^[3]
• Lanistes ovum Peters in Troschel, 1845^[3] - synonyms: Lanistes magnus Furtado; Lanistes olivaceus (Sowerby); Lanistes procerus; Lanistes elatior Martens, 1866; Lanistes ovum bangweolicus Haas, 1936; Lanistes connollyi Pain, 1954^[3] Lanistes ovum adansoni;^{[citation needed]} Lanistes olivaceus var. ambiguus^{[citation needed]}
• Lanistes pseudoceratodes (Wenz, 1928)^[2]
• Lanistes purpureus (Jonas, 1839)^[2][3]
• Lanistes solidus Smith, 1877^[2][3]
• Lanistes stuhlmanni Martens, 1897^[2][3]
• Lanistes varicus (Müller, 1774) - synonyms: Lanistes adansoni Kobelt, 1911; Lanistes millestriatus Pilsbry & Bequaert, 1927^[3]

Fossil species within the genus Lanistes include:

• † Lanistes asellus van Damme & Pickford, 1995^[4]
• † Lanistes bishopi Gautier^[4]
• † Lanistes gautieri van Damme & Pickford, 1995^[4]
• † Lanistes gigas van Damme & Pickford, 1995^[4]
• † Lanistes hadotoi van Damme & Pickford, 1995^[4]
• † Lanistes heynderycxi van Damme & Pickford, 1995^[4]
• † Lanistes nkondoensis van Damme & Pickford, 1995^[4]
• † Lanistes olukaensis^[4]
• † Lanistes senuti van Damme & Pickford, 1995^[4]
• † Lanistes trochiformis van Damme & Pickford, 1995^[4]

References

1. ^ Montfort P. D. de (1810). Conch. Syst. 2: 122.
2. ^ ^{a b c d e f g h i j k l m n o p q} "Lanistes". The apple snail website, accessed 16 May 2011.
3. ^ ^{a b c d e f g h i j k l m n o p q r s t u v w x y z aa} Brown D. S. (1994). Freshwater Snails of Africa and their Medical Importance. Taylor & Francis. ISBN 0 7484 0026 5.
4. ^ ^{a b c d e f g h i j k} van Damme D. & Pickford M. (1995). "The late Cenozoic ampullariidae (mollusca, gastropoda) of the Albertine Rift Valley (Uganda-Zaire)". Hydrobiologia 316(1): 1-32. doi:10.1007/BF00019372.
5. ^ Swainson (1840). Treat. Malacol., page 340.
6. ^ Grandidier (1887). Bull. Soc. malac. France 4: 191.
7. ^ ^{a b c} "Shell". The apple snail website, accessed 16 May 2011.

External links

• Lanistes at National Center for Biotechnology Information (NCBI) website.
• 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.