Polyceridae

Triopha catalinae: the front of the head with the rhinophores, gills behind the anus with wreath

The Squirrel snails ( Polyceridae ) are a family of slugs in the subordination of the nudibranchs. These are small to medium sized, exclusively marine shell-less snails that eat mainly bryozoans.

Features

The Polyceridae are in relation to other slugs of narrower, longer and higher form. They have a smooth or studded with a few warts body surface. The back often carries two ( in the genus Thecacera ) or more finger-like projections. In many species, the head has to wear a front sail ( velum ), which also several appendages ( head tentacles ), as in the genus Polycera. Because of these horn-like projections, the animals are also called Squirrel snails. The two seated at the head sensor, the rhinophores are laminated in most species. The around the anus at the back arranged gills can not be withdrawn.

The snails have a narrow radula with hook-shaped first and sometimes second molars. Instead of the original pine snails have strong Beißplatten which fulfill the same function. A goiter is missing.

The Polyceridae eat mostly bryozoans, whose flesh is rasped with the radula.

Like other slugs are hermaphrodites Polyceridae and copulate each other. They lay their eggs in mostly white Eischnüren, which hatch numerous veliger larvae, which feed on plankton and metamorphose after an extended pelagic phase to small slugs.

The Polyceridae include, among others spotted squirrel worm ( Palio dubia ), the Striped Squirrel Snail ( Polycera quadrilineata ), the Faroese Squirrel Snail ( Polycera faeroensis ), the Spotted Squirrel Snail ( Limacia clavigera ) and the helicopter - worm ( Thecacera picta).

System

After Bouchet and Rocroi ( 2005), the family Polyceridae one of five families in the superfamily Polyceroidea. This family includes seven genera:

  • Subfamily Polycerinae Alder & Hancock, 1845 genus Greilada
  • Genus Palio Gray, 1857
  • Genus Paliolla
  • Genus Polycera Cuvier, 1817 ( type genus )
  • Genus Polycerella A. E. Verrill, 1881
  • Genus Thecacera Fleming, 1828
  • Subfamily Kalinginae Pruvot -Fol, 1956 Genus Kalinga Alder & Hancock, 1864 ( type genus of the subfamily )
  • Subfamily Nembrothinae Burn, 1967 Genus Nembrotha ( Bergh, 1877) ( type genus of the subfamily )
  • Genus Roboastra ( Bergh, 1877)
  • Genus Tambja Burn, 1962
  • Subfamily Triophinae Odhner, 1941 Genus Colga ( Bergh, 1880)
  • Genus Crimora Alder and Hancock, 1855
  • Genus Kaloplocamus ( Bergh, 1893)
  • Genus Cabrilla Fewkes, 1889: synonym of Triopha Bergh, 1880
  • Genus Euplocamus Philippi, 1836: synonym of Kaloplocamus Bergh, 1892
  • Genus Histiophorus Pease, 1860: synonym of Plocamopherus Rüppell & Leuckart in Rüppell, 1828
  • Genus Issa Bergh, 1881: synonym of Colga Bergh, 1880
  • Genus Issena Iredale & O'Donoghue, 1923: synonym of Colga Bergh, 1880:
  • Genus Peplidia Lowe, 1842: synonym of Plocamopherus Rüppell & Leuckart in Rüppell, 1828
Heterobranchia Alice Pruvot-Fol Integrated Taxonomic Information System World Register of Marine Species
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