Streptaxidae


Streptaxidae is a family of carnivorous air-breathing land snails, terrestrial pulmonate gastropod mollusks in the clade
Stylommatophora.
Streptaxidae are monophyletic while all subfamilies and several genera are polyphyletic.
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. All streptaxids have well-developed radula, except Careoradula perelegans, which is the only known terrestrial gastropod without radula.
Altogether 66 species from the family Streptaxidae are listed in the 2010 IUCN Red List.

Distribution

The historical area of origin of the Streptaxidae is probably Gondwanaland.
The family is widely distributed across the tropical and subtropical areas of South America, Africa and Asia. 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. The genus Gibbulinella is found in the Canary Islands.
The species diversity of Streptaxidae reaches its maximum in sub-Saharan Africa.
With 13 genera and about 130 nominal species, the second most diverse streptaxid fauna can be found in Southeast Asia. Streptaxidae are the most diverse among tropical Asian carnivorous snails. In Indochina, streptaxid diversity was thought to comprise only 10 genera and about 40 species in 1967. However, in 2006–2016, 21 new species and one new genus had been described from Indochina. Thirty-seven species are recorded from Thailand, 10 from Myanmar, 45 from Vietnam, and 12 from Laos.

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

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.

2005 taxonomy

Only the one family, Streptaxidae, was recognized within the Streptaxoidea in the taxonomy of Bouchet & Rocroi (2005).
There are 7 subfamilies in the family Streptaxidae according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005, that follows Schileyko :
  • Enneinae Bourguignat, 1883 - synonym: Streptostelidae Bourguignat, 1889
  • Gulellinae Rowson, 2024
  • Marconiinae Schileyko, 2000
  • Odontartemoninae Schileyko, 2000
  • Orthogibbinae Germain, 1921 - synonyms: Gibbinae Steenberg, 1936; Gonidominae Steenberg, 1936
  • Primigulellinae Rowson, 2024
  • Streptaxinae Gray, 1860 - synonym: Artemonidae Bourguignat, 1889
;Synonyms:
  • Ptychotrematinae Pilsbry, 1919: synonym of Enneinae Bourguignat, 1883

2010 taxonomy

Sutcharit et al. have established a new family Diapheridae within Streptaxoidea and they have added two genera Diaphera and Sinoennea into Diapheridae.
The later review "A review of the Diapheridae" in 2020 by Páll-Gergely, B., Hunyadi, A., Grego, J., Sajan, S., Tripathy, B. & Chen, Z.-Y. showed the family Diapheridae to stand separate from Streptaxidae.
In the recent decades, most of the taxonomic and systematic research on streptaxids has been performed on sub-Saharan African taxa. Only a few publications focus on South American or Asian groups.

Genera

Genera in the family Streptaxidae include:

Enneinae

Avakubia Pilsbry, 1919Costigulella Pilsbry, 1919Digulella F. Haas, 1934Mirigulella Pilsbry & Cockerell, 1933Paucidentella Thiele, 1933Pseudavakubia de Winter & Vastenhout, 2013Ptychotrema L. Pfeiffer, 1853Pupigulella Pilsbry, 1919 Rhabdogulella F. Haas, 1934Silvigulella Pilsbry, 1919Sphincterocochlion Verdcourt, 1985Sphinctostrema Girard, 1894Streptostele Dohrn, 1866Tomostele Ancey, 1885

Gulellinae

Austromarconia van Bruggen & de Winter, 2003Dadagulella Rowson & Tattersfield, 2013Gulella Pfeiffer, 1856Pseudelma Kobelt, 1904

Marconiinae

Gonaxis J. W. Taylor, 1877

Odontartemoninae

Artemonopsis Germain, 1908Lamelliger Ancey, 1884Pseudogonaxis Thiele, 1932Tanzartemon Tattersfield & Rowson, 2011Tayloria Bourguignat, 1889

Orthogibbinae

Acanthennea Martens, 1898 - with the only species Acanthennea erinacea Augustula Thiele, 1931 - with the only species Augustula braueri Careoradula Gerlach & van Bruggen, 1999 - with the only species Careoradula perelegans Conturbatia Gerlach, 2001 - with the only species Conturbatia crenata Gerlach, 2001Gerlachina Rowson, 2024Gibbulinella Wenz, 1920

Primigulellinae

Aenigmigulella Pilsbry & Cockerell, 1933Juventigulella Tattersfield, 1998Microstrophia Möllendorff, 1887Mirellia Thiele, 1933Primigulella Pilsbry, 1919

Streptaxinae

Afristreptaxis Thiele, 1932Carinartemis Siriboon & Panha, 2014Discartemon Pfeiffer, 1856Edentulina L. Pfeiffer, 1856Elma Adams, 1866Embertonina Rowson, 2024Fischerpietteus Emberton, 2003Glyptoconus Möllendorff, 1894Haploptychius Kobelt, 1905Hypselartemon Wenz, 1947Indoartemon Forcart, 1946Makrokonche Emberton, 1994Martinella Jousseaume, 1887Micrartemon Möllendorff, 1890Nagyelma Páll-Gergely & Hunyadi, 2021Odontartemon L. Pfeiffer, 1856Oophana Ancey, 1884Pallgergelyia Thach, 2017Perrottetia Kobelt, 1905

Unsorted to subfamily

Campolaemus Pilsbry, 1892
  • † Goniodomulus Harzhauser & Neubauer in Harzhauser et al., 2016Pallgergelyia Thach, 2017Panhartemis Siriboon, 2023
  • † Pfefferiola Harzhauser & Neubauer, 2021
;Notes:Scolodonta Doering, 1875 used to be classified within Streptaxinae, but Scolodonta is the type genus of the family Scolodontidae.

Synonyms

  • Subfamily Gibbinae Steenberg, 1936: synonym of Orthogibbinae Germain, 1921
  • Subfamily Gonidominae Steenberg, 1936: synonym of Orthogibbinae Germain, 1921
  • Subfamily Ptychotrematinae Pilsbry, 1919: synonym of Enneinae Bourguignat, 1883Aberdaria Blume, 1965: synonym of Primigulella Pilsbry, 1919 Acanthenna: synonym of Acanthennea E. von Martens, 1898 Adjua Chaper, 1885: synonym of Ptychotrema Chaper, 1885 represented as Ptychotrema L. Pfeiffer, 1853 Alcidia Bourguignat, 1890: synonym of Streptaxis Gray, 1837Artemon H. Beck, 1837: synonym of Streptaxis Gray, 1837Campylaxis Ancey, 1888: synonym of Streptostele Dohrn, 1866Carychiopsis E. von Martens, 1895: synonym of Ennea H. Adams & A. Adams, 1855: synonym of Ptychotrema H. Adams & A. Adams, 1855 represented as Ptychotrema L. Pfeiffer, 1853Colpanostoma Bourguignat, 1890: synonym of Tayloria Bourguignat, 1890 represented as Tayloria Bourguignat, 1890 Conogulella Pilsbry, 1919: synonym of Gulella Pilsbry, 1919 represented as Gulella L. Pfeiffer, 1856Ennea H. Adams & A. Adams, 1855 - type genus of the subfamily : synonym of Ptychotrema H. Adams & A. Adams, 1855 represented as Ptychotrema L. Pfeiffer, 1853Enneastrum L. Pfeiffer, 1856: synonym of Ennea H. Adams & A. Adams, 1855: synonym of Ptychotrema H. Adams & A. Adams, 1855 represented as Ptychotrema L. Pfeiffer, 1853Eustreptaxis L. Pfeiffer, 1878: synonym of Streptaxis Gray, 1837 Eustreptostele Germain, 1915: synonym of Streptostele Ancey, 1885: synonym of Tomostele Ancey, 1885Gibbonsia Bourguignat, 1890: synonym of Gigantaxis Tomlin, 1930: synonym of Tayloria Bourguignat, 1890 represented as Tayloria Bourguignat, 1890 Gibbulina Beck, 1837: synonym of Gibbus Montfort, 1810 Gigantaxis Tomlin, 1930: synonym of Tayloria Bourguignat, 1890 represented as Tayloria Bourguignat, 1890Haplonepion Pilsbry, 1919: synonym of Ptychotrema Pilsbry, 1919 represented as Ptychotrema L. Pfeiffer, 1853Huttonella Pfeiffer, 1855: synonym of Gulella L. Pfeiffer, 1856 represented as Gulella L. Pfeiffer, 1856Idolum L. Pfeiffer, 1856: synonym of Gonidomus Swainson, 1840 Indoennea Kobelt, 1904: synonym of Sinoennea Kobelt, 1904 Ischnostele C. R. Boettger, 1915: synonym of Streptostele Bourguignat, 1883 represented as Streptostele Dohrn, 1866Luntia E.A. Smith, 1898: synonym of Streptostele Ancey, 1885: synonym of Tomostele Ancey, 1885 Marconia Bourguignat, 1889 - type genus of the subfamily: synonym of Gonaxis J. W. Taylor, 1877 Macrogonaxis Bequaert & Clench, 1936: synonym of Tayloria Thiele, 1932 represented as Tayloria Bourguignat, 1890Marconia Bourguignat, 1890: synonym of Gonaxis J. W. Taylor, 1877 Maurennea: synonym of Gulella Schileyko, 2000 represented as Gulella L. Pfeiffer, 1856Nevillia E. von Martens, 1880: synonym of Microstrophia Möllendorff, 1887
  • † Oppenheimiella Pfeffer, 1930 : synonym of † Pfefferiola Harzhauser & Neubauer, 2021 Orthogibbus Germain, 1919: synonym of Gonospira Swainson, 1840Parennea Pilsbry, 1919: synonym of Ptychotrema Pilsbry, 1919 represented as Ptychotrema L. Pfeiffer, 1853Pseudartemon J. Mabille, 1887: synonym of Haploptychius Kobelt, 1905Raffraya Bourguignat, 1883: synonym of Streptostele Bourguignat, 1883 represented as Streptostele Dohrn, 1866Sinistrexcisa de Winter, Gómez & Prieto, 1999: synonym of Ptychotrema L. Pfeiffer, 1853Somalitayloria Verdcourt, 1962: synonym of Tayloria Verdcourt, 1962 represented as Tayloria Bourguignat, 1890Stenomarconia Germain, 1934: synonym of Gonaxis Germain, 1934 represented as Gonaxis J. W. Taylor, 1877Thaumatogulella F. Haas, 1951: synonym of Mirellia Thiele, 1933Varicostele Pilsbry, 1919: synonym of Streptostele Pilsbry, 1919 represented as Streptostele Dohrn, 1866Webbia Odhner, 1932: synonym of Gibbulinella Wenz, 1920