Flabellinidae
| Flabellinidae | ||||||||||||
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Flabellina affinis eats polyps from Eudendrium racemosum |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Flabellinidae | ||||||||||||
| Bergh , 1889 |
The Flabellinidae are a family of thread snails in the suborder of the nudibranchs . These are mostly small to medium-sized, exclusively marine, shell -less snail species that mainly eat hydrozoa and sea anemones .
features
The Flabellinidae have two long movable mouth feelers. The usually shorter rhinophores located above the head can be smooth, lamellar or covered with papillae. An emergency border separating the back and flanks may be present. The back is covered with regular or irregular rows of cerata , into which, like other thread snails, extensions of the midgut gland lead, the sections of which correspond to the rows of the cerata. The runners end in so-called nettle sacks, also known as cnido sacks, in which the nettle capsules of the cnidarians that are eaten are stored and serve to defend the snails against predators.
The posterior teeth of the three-row radula are mostly serrated, rarely smooth. The jaws are also covered with teeth. The anus opens on the right side of the body next to the rows of cerata, rarely on the back in the gap between the cerata rows, which are supplied by the right and left lobes of the midgut gland.
Like other thread snails, the Flabellinidae are hermaphrodites . They have an unarmed penis, a convoluted tubular seminal vesicle, a copulatrix bursa, which houses the sperm of the sex partner, and a fertilization chamber. The snails mate with each other and lay their eggs in long egg strings, in whose transparent shell you can see the numerous eggs. Numerous Veliger larvae hatch from these, feed on plankton and after a long pelagic phase they metamorphose into small thread snails .
The Flabellinidae eat cnidarians, especially hydrozoan polyps , but also sea anemones . Preferred prey animals of many species are hydrozoans of the genus Eudendrium .
Some types
The Flabellinidae are usually no longer than four centimeters. The Spanish scarf ( Flabellina iodinea ) from the North American Pacific coast is one of the largest species, measuring up to 7 cm . In the North Sea the family is represented by the red-violet thread snail ( Flabellina pedata , formerly Coryphella pedata ), the milky thread snail ( Flabellina pellucida ), the red-backed thread snail ( Flabellina verrucosa ), the salmon thread snail ( Flabellina salmonacea ) and Flabellina browni .
Systematics
According to Bouchet and Rocroi (2005), the Flabellinidae family is one of two families in the superfamily Flabellinoidea . Seven genera belong to the family:
- Babakina Roller, 1973
- Calmella Eliot, 1910
- Cumanotus Odhner, 1906
- Flabellina Gray, 1833 - type genus
- Flabellinopsis MacFarland, 1966
- Paracoryphella Miller, 1971
- Tularia Burn, 1966 - only species: Tularia bractea (Burn, 1962)
The generic names Coryphella Gray, 1850 (which referred to a group of very small thread snails), Coryphellina O'Donoghue, 1929, Himatella Bergh, 1890 and Himatina Thiele, 1931, are synonyms of the older generic name Flabellina Gray, 1833. Babaina Roller, 1972 (a homonym ) and Rioselleolis Ortea, 1979 are synonyms of Babakina Roller, 1973.
literature
- Luise Schmekel, Adolf Portmann: Opisthobranchia of the Mediterranean: Nudibranchia and Saccoglossa . Springer-Verlag, Berlin Heidelberg New York 1982. Flabellinidae Rafinesque, 1815 : p. 183.
- Philippe Bouchet & Jean-Pierre Rocroi: Part 2. Working classification of the Gastropoda . Malacologia, 47: 239-283, Ann Arbor 2005 ISSN 0076-2997
