Pachychilidae

Pachychilidae
Temporal range: Paleogene - recent
Two shells of Pachychilus laevisimus
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Superfamily: Cerithioidea
Family: Pachychilidae
P. Fischer & Crosse, 1892
Type genus
Pachychilus
I. Lea & H. C. Lea, 1851
Diversity
191-226 extant species
Synonyms
  • Brotiinae Golikov & Starobogatov, 1987
  • Fauninae Cossmann, 1909
  • Melanatriinae Thiele, 1921
  • Potadomatinae Pilsbry & Bequaert, 1927

Pachychilidae, common name pachychilids, is a taxonomic family of freshwater snails, gastropod molluscs in the clade Sorbeoconcha.

Distribution

The global distribution of the family Pachychilidae

Pachychilids are freshwater snails with a worldwide distribution in the tropics. Representatives are found in South and Central America, Africa, Madagascar, South and South-east Asia and tropical Australia (Queensland: Torres Strait Islands).

Description

Pachychilids have an operculum, which is concentric and multispiral.

Ecology

All species in the family inhabit freshwater except Faunus ater, which is a brackish water snail found in estuaries and other coastal habitats. Pachychilids are either oviparous (lay eggs), ovoviviparous or viviparous (retain developing eggs and youngs in special incubatory structures).

Notes on the taxonomy

The name is derived from a combination of the words 'pachy' (Greek = thick) and the suffix '-chilus' (Greek = Lip), meaning 'thick lipped' - with respect to the thickened aperture of the shell in some species. Most 20th-century authors did not recognize Pachychilidae as an independent family, but affiliated species under different groups, such as Thiaridae and Pleuroceridae. However, recent revisions based on molecular and morphological evidence have proven their independent and distinct status from the former. This family has no subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

Genera

Shells of various pachychilid species

Genera within the family Pachychilidae include:

  • Bellatara Strand, 1928 - with only one species Bellatara janus (Mayer, 1870)
  • Brotia H. Adams, 1866
  • Doryssa Swainson, 1840
  • Eginea Pacaud & Harzhauser, 2012
  • Faunus de Montfort, 1810 with the only species Faunus ater (Linnaeus, 1758)
  • Jagora Köhler & Glaubrecht, 2003
  • Jponsia Pacaud & Harzhauser, 2012
  • Madagasikara Köhler & Glaubrecht, 2010 - synonym: Melanatria Bowdich, 1822 auctt.
  • Nodifaunus Olsson, 1944
  • Pachychilus I. Lea & H. C. Lea, 1851 - type genus of the family Pachychilidae
  • Paracrostoma Cossmann, 1900
  • Potadoma Swainson, 1840
  • Pseudobellardia Cox, 1931
  • Pseudopotamis Martens, 1894
  • Sulcospira Troschel, 1858 - synonym: Adamietta Brandt, 1974
  • Tinnyea Hantken, 1887
  • Tylomelania Sarasin & Sarasin, 1897
  • Wingeastonia K. Martin, 1906
Genera brought into synonymy
  • Acrostoma Brot, 1871: synonym of Paracrostoma Cossmann, 1900
  • Antimelania P. Fischer & Crosse, 1892: synonym of Brotia H. Adams, 1866
  • Brotella Rovereto, 1899: synonym of Paracrostoma Cossmann, 1900
  • Fauninae Cossmann, 1909 (subfamily) : synonym of Pachychilidae P. Fischer & Crosse, 1892
  • Melanatria Bowdich, 1822: synonym of Faunus Montfort, 1810
  • Oxymelania Crosse & P. Fischer, 1892: synonym of Pachychilus I. Lea & H. C. Lea, 1851
  • Pirena Lamarck, 1822: synonym of Faunus Montfort, 1810
  • Sphaeromelania Rovereto, 1899: synonym of Pachychilus I. Lea & H. C. Lea, 1851
  • Wanga Chen, 1943: synonym of Brotia H. Adams, 1866

Cladogram

A cladogram based on sequences of mitochondrial 16S ribosomal RNA sequences showing phylogenic relations of Pachychilidae:

Pachychilidae

Faunus ater

Potadoma freethi

Doryssa consolidata

Sulcospira hainanensis

Sulcospira testudinaria

Sulcospira housei

Brotia

Brotia pagodula

Brotia sumatrensis

Paracrostoma

Paracrostoma martini

Paracrostoma tigrina

Pseudopotamis

Pseudopotamis supralirata

Pseudopotamis semoni

Tylomelania

Tylomelania perfecta

Tylomelania neritiformis

Jagora

Jagora dactylus

Jagora asperata

Pachychilus

Pachychilus indiorum

Pachychilus conicus

Madagasikara

Madagasikara madagascariensis

Madagasikara spinosa

Madagasikara zazavavindrano

Madagasikara vazimba

Madagasikara vivipara