Achatinellidae Explained

Achatinellidae is a family of tropical air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Pupilloidea.

Taxonomy

It was previously the only family in the superfamily Achatinelloidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). It is now classified under the superfamily Pupilloidea.

The family Achatinellidae represents a diverse adaptive radiation. All species of tree-snail in Hawaii are believed to have come from a single ancestral snail. How that ancestral snail made the 3800km (2,400miles) trip across the ocean is unknown. A longstanding theory is that a bird carried a notably smaller ancestor across the ocean and dropped it on the islands, as bird mediated dispersal has been documented in other snail species. Alternative theories include that it floating across the ocean on a mat of debris, or that it island hopped across the Pacific in a combination of the theories.^[1]

Subfamilies in the family Achatinellidae include:

• Achatinellinae Gulick, 1873 - synonym: Helicterinae Pease, 1870 (inv.)
• Auriculellinae Odhner, 1921
• Elasmatininae Iredale, 1937
  • tribe Elasmatinini Iredale, 1937 - synonyms: Strobilidae Zilch, 1959 (n.a.); Pitysinae Cooke & Kondo, 1961
  • tribe Antonellini Cooke & Kondo, 1961
  • tribe Tubuaiini Cooke & Kondo, 1961
• Pacificellinae Steenberg, 1925
  • tribe Pacificellini Steenberg, 1925 - synonym: Tornatellinoptini Cooke & Kondo, 1961
  • tribe Lamellideini Cooke & Kondo, 1961
• Tekoulininae Solem, 1972
• Tornatellidinae Cooke & Kondo, 1961
  • tribe Tornatellidini Cooke & Kondo, 1961
  • tribe Tornatellariini Cooke & Kondo, 1961
• Tornatellininae Sykes, 1900
  • tribe Tornatellinini Sykes, 1900
  • tribe Elasmiatini Kuroda & Habe, 1949

Anatomy

In this family, the number of haploid chromosomes lies between 16 and 25 (according to the values in the table).^[2]

Distribution

This family of snails occurs widely in the Pacific islands. They are at their most diverse in the Hawaiian group.^{[3] [4]}

Genera

Genera in the family Achatinellidae include:

Achatinellinae

• Achatinella Swainson, 1828 - type genus of the subfamily Achatinellinae
• Partulina Pfeiffer, 1854^[5]
• Perdicella Pease, 1870^[5]
• Newcombia Pfeiffer, 1854^[5]

Auriculellinae

• Auriculella Pfeiffer, 1854 - type genus of the subfamily Auriculellinae^[5]

Elasmatininae

• tribe Elasmatinini
• tribe Antonellini
• tribe Tubuaiini
  • Tubuaia

Pacificellinae

• tribe Pacificellini
  • Tornatellinops Pilsbry & Cooke, 1915
• tribe Lamellideini
  • Lamellidea Pilsbry, 1910

Tekoulininae

• • Tekoulina Solem, 1972

Tornatellidinae

• tribe Tornatellidini
  • Tornatellides Pilsbry, 1910 - type genus of the tribe Tornatellidini
• tribe Tornatellariini
  • Tornatellaria Pilsbry, 1910 - type genus of the tribe Tornatellariini

Tornatellininae

• tribe Tornatellinini
  • Tornatellina L. Pfeiffer, 1842 - type genus the tribe Tornatellinini
• tribe Elasmiatini
  • Elasmias Pilsbry, 1910 - type genus of the tribe Elasmiatini

unsorted

• Gulickia Cooke, 1915^[6]
• † Hotumatua Kirch, Christensen & Steadman, 2009 - Hotumatua anakenana Kirch, Christensen & Steadman, 2009^[7]
• Tornatellinops Pilsbry, 1915
• Tornelasmias Iredale, 1944

Notes and References

1. Holland. Brenden S. Hadfield. Michael G. August 2004. Origin and diversification of the endemic Hawaiian tree snails (Achatinellidae: Achatinellinae) based on molecular evidence. Molecular Phylogenetics and Evolution. en. 32. 2. 588–600. 10.1016/j.ympev.2004.01.003. 15223040.
2. Barker G. M. Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. In Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, . 1-146, cited pages: 139 and 142.
3. [Arthur William Baden Powell|Powell A. W. B.]
4. [Charles Montague Cooke|Cooke, C. M.]
5. Molecular Phylogenetics and Evolution. 10.1016/j.ympev.2004.01.003. 15223040. Origin and diversification of the endemic Hawaiian tree snails (Achatinellidae: Achatinellinae) based on molecular evidence. 2004. Holland. Brenden S. Hadfield. Michael G. 32. 2. 588–600.
6. Cowie R. H. (1996). "Gulickia alexandri". 2006 IUCN Red List of Threatened Species. Downloaded on 7 August 2007.
7. Kirch P. V., Christensen C. C. & Steadman D. W. (2009). "Subfossil Land Snails from Easter Island, Including Hotumatua anakenana, New Genus and Species (Pulmonata: Achatinellidae) 1". Pacific Science 63(1): 105-122. PDF.