Clio (gastropod) explained

The genus Clio is a taxonomic group of small floating sea snails, pelagic marine opisthobranch gastropod mollusks, the sole genus belonging to the family Cliidae^[1]

All species in this genus are characterised by a bilaterally symmetric, straight or adapically dorso-ventrally slightly curved shell, with an elliptical to triangular transverse section; protoconch separated, globular or elliptical, frequently with a spine at the tip.Subgenera are used for some species (e.g. Clio s.str., Balantium Bellardi, 1872, Bellardiclio Janssen, 2004), but most species still need to be assigned to one of these.

Numerous fossil species have been described.

Species

Recognised extant species are:

• Clio andreae (Boas, 1886)
  • Distribution : north Atlantic, bathypelagic species.
• Clio antarctica Dall, 1908
• Clio bartletti van der Spoel, 1978
  • Distribution: central Atlantic (Pleistocene fossil).
• Clio campylura (Tesch, 1948)
• Clio chaptalii J. E. Gray, 1850
  • Distribution : tropical, circumglobal.
• Clio convexa convexa (Boas, 1886)
  • Distribution: tropical, Indo-Pacific
• Clio convexa cyphosa Rampal, 2002
  • Distribution: Red Sea and Gulf of Aden.
• Clio cuspidata (Bosc, 1802)
  • Distribution : tropical/subtropical, circumglobal.
• † Clio oblonga Rampal, 1996
• Clio orthotheca (Tesch, 1904)
• Clio piatkowskii van der Spoel, Schalk & Bleeker, 1992
  • Distribution: Antarctic.
• Clio polita Pelseneer, 1888
• Clio pyramidata Linnaeus, 1767
  • Distribution : north Atlantic
  • Height : to over 20 mm.

Formae:

• • • forma excisa van der Spoel, 1963
    • forma lanceolata Lesueur, 1813 (tropical/subtropical, circumglobal)
    • forma martensi (Pfeiffer, 1880) ??
    • forma sulcata (Pfeffer, 1879)

The true status of these formae has to be evaluated, they might be real formae, subspecies, or even species.

• Clio recurva (Children, 1823)
  • Distribution : tropical-subtropical, circumglobal (bathypelagic species)**
    • Height: to over 30 mm
• Clio sulcata (Pfeffer, 1879)

Species brought into synonymy:

• Clio australis: synonym of Clione limacina australis (Bruguière, 1792)
• Clio borealis (Pallas, 1774): synonym of Clione limacina (Phipps, 1774)
• Clio helicina Phipps, 1774: synonym of Limacina helicina (Phipps, 1774)

References

• Vaught, K.C. (1989). A classification of the living Mollusca. American Malacologists: Melbourne, FL (USA). . XII, 195 pp
• Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 180–213
• Willan, R. (2009). Opisthobranchia (Mollusca). In: Gordon, D. (Ed.) (2009). New Zealand Inventory of Biodiversity. Volume One: Kingdom Animalia. 584 pp

Notes and References

1. Bouchet, P.; Gofas, S. (2012). Clio. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137751 on 2012-07-24