Hunter Snails

Streptaxidae is a family of carnivorous air-breathing land snails, terrestrial pulmonate gastropod mollusks in the clade Stylommatophora. Six Streptaxidae subfamilies are accepted in the 2005 taxonomy of the Gastropoda by Bouchet & Rocroi.

Streptaxidae are carnivorous except for one species Edentulina moreleti, which is herbivorous.^[3] All streptaxids have well-developed radula, except Careoradula perelegans, which is the only known terrestrial gastropod without radula.^[4]

Altogether 66 species from the family Streptaxidae are listed in the 2010 IUCN Red List.^[5]

Distribution

The historical area of origin of the Streptaxidae is probably Gondwanaland.^[6]

The family is widely distributed across the tropical and subtropical areas of South America, Africa and Asia.^[7] The Recent native distribution of Streptaxidae includes South America, Africa, Arabia, Madagascar, Seychelles, Mayotte, Comores, Mauritius, Réunion, Rodrigues, India, Sri Lanka, Andamans, South-East Asia and the Philippines.^[2] The genus Gibbulinella is found in the Canary Islands.^[2]

The species diversity of Streptaxidae reaches its maximum in sub-Saharan Africa.^[7]

With 13 genera and about 130 nominal species, the second most diverse streptaxid fauna can be found in Southeast Asia.^[7] Streptaxidae are the most diverse among tropical Asian carnivorous snails.^[7] In Indochina, streptaxid diversity was thought to comprise only 10 genera and about 40 species in 1967.^[8] However, in 2006-2016, 21 new species (more than half the previous total) and one new genus had been described from Indochina.^[8] Thirty-seven species are recorded from Thailand, 10 from Myanmar, 45 from Vietnam,^[8][9] and 12 from Laos.^[8]

Description

Streptaxids can generally be recognized by their eccentric or cylindrical shells, while the animals have a bright yellow to red or orange body with external hook-like structures on the everted penis.^[7]

Early classifications of the family such as Wilhelm Kobelt (1905–6), used mainly shell shape and the arrangement of apertural dentition.^[8] However, many shell characters are highly conserved or occur recurrently, making some species and genera difficult to separate.^[8] The reproductive organs of streptaxids can also be taxonomically significant.^[8]

Taxonomy

Prior to Schileyko’s revision in 2000 only two subfamilies, the Streptaxinae and the Enneinae had been recognized, which were primarily based on their shell morphology.^[7]

2005 taxonomy

Only the one family, Streptaxidae, was recognized within the Streptaxoidea in the taxonomy of Bouchet & Rocroi (2005).^[10]

There are 6 subfamilies in the family Streptaxidae according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005, that follows Schileyko (2000):^[11]

• Streptaxinae Gray, 1860 - synonym: Artemonidae Bourguignat, 1889
• Enneinae Bourguignat, 1883^[12] - synonym: Streptostelidae Bourguignat, 1889
• Marconiinae Schileyko, 2000^[13]
• Odontartemoninae Schileyko, 2000^[14]
• Orthogibbinae Germain, 1921^[15] - synonyms: Gibbinae Steenberg, 1936; Gonidominae Steenberg, 1936
• Ptychotrematinae Pilsbry, 1919^[16]

2010 taxonomy

Sutcharit et al. (2010)^[2] have established a new family Diapheridae within Streptaxoidea and they have added two genera Diaphera and Sinoennea into Diapheridae.^[2]

In the recent decades, most of the taxonomic and systematic research on streptaxids has been performed on sub-Saharan African taxa.^[7] Only a few publications focus on South American or Asian groups.^[7]

Genera

Genera in the family Streptaxidae include:

Streptaxinae

• Acanthennea Martens, 1898^[2] - with the only species Acanthennea erinacea (Martens, 1898)^[6]
• Augustula Thiele, 1931^[2] - with the only species Augustula braueri (Martens, 1898)^[6]
• Careoradula Gerlach & van Bruggen, 1999^[2] - with the only species Careoradula perelegans (Martens, 1898)^[6]
• Discartemon Pfeiffer, 1856^[2]
• Glabrennea^[2]
• Glyptoconus Möllendorff, 1894^[2]
• Hypselartemon Wenz, 1947^[2][17]
• Indoartemon Forcart, 1946^[2]
• Martinella Jousseaume, 1887^[2]
• Micrartemon Möllendorff, 1890^[2]
• Perrottetia Kobelt, 1905^[2]
• Platycochlium Laidlaw, 1950^[2]
• Rectartemon Baker, 1925^[2]
• Sairostoma Haas, 1938^[2]
• Seychellaxis^[2]
• Silhouettia Gerlach & van Bruggen, 1999^[2][6] - with the only species Silhouettia silhouettae (Martens, 1898)^[6]
• Stemmatopsis^[2]
• Stereostele Pilsbry, 1919^[2] - with the only species Stereostele nevilli (Adams, 1868)^[6]
• Streptartemon Kobelt, 1905^[2]
• Streptaxis Gray, 1837^[2] - type genus of the family Streptaxidae
• Tonkinia Mabille, 1887^[2]

Enneinae

• Bruggennea Dance, 1972^[2][18]
• Ennea H. Adams & A. Adams, 1855^[2] - type genus of the subfamily
• Elma Adams, 1866^[2]
• Gulella Pfeiffer, 1856[2]
• Indoennea Kobelt, 1904^[2]
• Juventigulella Tattersfield, 1998
• Maurennea^[2]
• Microstrophia Möllendorff, 1887^[2]
• Primigulella Pilsbry, 1919
• Pupigulella Pilsbry, 1919
• Streptostele Dohrn, 1866^[2]
• Varicostele Pilsbry, 1919^[2]

Marconiinae

• Macrogonaxis Bequaert & Clench, 1936^[19][2]
• Marconia Bourguignat, 1889^[2] - type genus of the subfamily
• Stenomarconia Germain, 1934^[2]

Odontartemoninae

• Afristreptaxis Thiele, 1932^[2]
• Artemonopsis Germain, 1908^[2]
• Gigantaxis Tomlin, 1930^[2]
• Odontartemon L. Pfeiffer, 1856^[2] - type genus of the subfamily
• Pseudogonaxis Thiele, 1932^[2]
• Somalitayloria Verdcourt, 1962^[2]
• Tayloria Bourguignat, 1889^[2]

Orthogibbinae

• Edentulina Pfeiffer, 1856^[2]
• Gibbulinella Wenz, 1920^[2]
• † Gibbus Montfort, 1810 - this genus was endemic to Mauritius and it is now extinct^[2]
• Gonaxis Taylor, 1877^[2]
• † Gonidomus Swainson, 1840 - this genus was endemic to Mauritius and it is now extinct^[2]
• Gonospira Swainson, 1840^[2]
• Haploptychius Kobelt, 1905^[2]
• Imperturbatia Martens, 1898^[2]
• Oophana Ancey, 1884^[2]
• Orthogibbus Germain, 1919 - type genus of the subfamily
• Plicadomus Swainson, 1840^[2]
• Priodiscus Martens, 1898^[2]
• Pseudelma Kobelt, 1904^[2]

Ptychotrematinae

• Dadagulella Rowson & Tattersfield, 2013^{[20][note 1]}
• Huttonella Pfeiffer, 1855^[2]
• Mirellia Thiele, 1933^[2]
• Parennea Pilsbry, 1919^[2]
• Ptychotrema L. Pfeiffer, 1853^[2] - type genus of the subfamily
• Sinistrexcisa De Winter, Gomez & Prieto, 1999^[2]

Unsorted to subfamily:

• Conturbatia Gerlach, 2001 - with the only species Conturbatia crenata Gerlach, 2001^[21]
• Costigulella Pilsbry, 1919 - formerly included in Gulella
• Parvedentulina Emberton & Pearce, 2000 - endemic to Madagascar^[22]

Notes:

• Scolodonta Doering, 1875 used to be classified within Streptaxinae,^[2] but Scolodonta is the type genus of the family Scolodontidae.^[10]

See also

• taxa of Streptaxidae described by Adolph Cornelis van Bruggen

References

This article includes CC-BY-3.0 text from the reference^[7] and CC-BY-4.0 from the reference^[8]