Star snails
Star snails | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Doridacea | ||||||||||||
Thiele , 1931 |
The star snails (Doridacea) are a suborder of the nudibranch within the order hind gill snails . The small to large shellless snails that occur in all oceans are carnivores that feed on various sessile animals.
features
The star snails often have a flattened body and no appendages (cerata), but instead often have small nodules. There are sclerites in the skin . The snails have a pair of long antennae, the rhinophores , which are very sensitive to odor and flow . Like other nudibranch snails, star snails lack a mantle cavity and shell. The anus is located in the upper third of the back and is surrounded by a ring of external gills , on the often star-like shape of which the name of the snail is based.
The star snails mostly live on stony ground and eat sessile animals , depending on the species these are sponges , bog animals , sea squirts or barnacles .
The star snails are hermaphrodites that mate with each other with their penises . Every animal produces eggs and sperm and has two female openings - the mouths of the vagina and fallopian tubes (oviduct) - and a male sex opening with the spermatic duct , into which the penis is withdrawn. A blister behind the vagina, the bursa, initially takes in the sperm of the sex partner. Sperm for the later internal fertilization of egg cells are stored in a second bladder, the seminal sac ( receptaculum seminis ). The fertilization takes place in an enlargement of the fallopian tube. The eggs are laid in clusters of thousands of egg capsules, from which Veliger larvae hatch. During their pelagic phase, these occasionally carry a tiny shell that is later lost, so that the metamorphosis creates a shell -less slug. An exception among the nudibranchs are some species from the Dendrodorididae family , in which there is a direct development, i.e. ready-made snails hatch.
Systematics
According to Bouchet and Rocroi (2005), star snails (Doridacea) include four superfamilies with fifteen families. Some species examples are also given:
- Superfamily Doridoidea
- Family Dorididae , sea lemons
- Wart humps ( Doris verrucosa )
- Sea lemon ( Archidoris pseudoargus )
- Family Cadlinidae
- Smooth star snail ( Cadlina laevis )
- Family Actinocyclidae
- Family Chromodorididae , magnificent star snails
- Koi splendor star snail (
- Family Dorididae , sea lemons
- Family Discodorididae
- Family Phyllidiidae , Wart snails
- Eye spot warthog ( Phyllidia ocellata )
- Family Dendrodorididae
- Family Mandeliidae
- Family Onchidorididae
- Soft waxy star snail ( Acanthodoris pilosa )
- Red star snail ( Adalaria proxima )
- Diaphorodoris luteocincta
- Diaphorodoris papillata
- Brown-spotted star snail ( Onchidoris bilamellata )
- Rough star snail ( Onchidoris muricata )
- Corambidae family
- Family Goniodorididae
- White style snail ( Ancula gibbosa )
- White-transparent goniodoris ( Goniodoris nodosa )
- Family Polyceridae , squirrel snails (neon star snails)
- Spotted squirrel snail ( Palio dubia )
- Striped squirrel snail ( Polycera quadrilineata )
- Faroese squirrel snail ( Polycera faeroensis )
- Spotted squirrel snail ( Limacia clavigera )
- Helicopter snail ( Thecacera picta )
- Family Aegiridae (in Bouchet and Rocroi 2005 misspelling Aegiretidae).
- Family Gymnodorididae
- Family Hexabranchidae , Spanish dancers
- Family Okadaiidae
literature
- Luise Schmekel, Adolf Portmann: Opisthobranchia of the Mediterranean: Nudibranchia and Saccoglossa . Springer-Verlag, Berlin Heidelberg New York 1982. Subordo Doridacea Odhner, 1934 : pp. 56-140.
- Adam Sedgwick, Joseph Jackson Lister, Sir Arthur Everett Shipley: A Student's Text-book of Zoology: Protozoa to Chaetognatha . S. Sonnenschein and Company, 1898. Doridioidea : p. 412.
- Philippe Bouchet & Jean-Pierre Rocroi: Part 2. Working classification of the Gastropoda . Malacologia, 47: 239-283, Ann Arbor 2005, ISSN 0076-2997 .
- Victor Millard: Classification of the Mollusca. A Classification of World Wide Mollusca . Rhine Road, South Africa 1997, ISBN 0-620-21261-6 .
- Rudie H. Kuiter , Helmut Debelius : Nudibranchs of the world's oceans: 1200 species worldwide. Kosmos Verlag, Stuttgart 2007. ISBN 3-440-11133-4 .
Web links
- The Marine Flora & Fauna of Norway: Nudibranchs - Doridacea
- Ask Ms. Klara: How do the snails do it (pictures with copulating star snails)
Individual evidence
- ↑ Doridacea . WoRMS . Retrieved December 20, 2013.
- ↑ Jeffrey HR Goddard (2005): Ametamorphic direct development in Dendrodoris behrensi (Nudibranchia: Dendrodorididae), with a review of developmental mode in the family . Proceedings of the California Academy of Sciences 56 (19), pp. 201-211. ( Abstract, doc ( Memento of the original dated February 22, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. )