Hungary cap
| Hungary cap | ||||||||||||
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Housing of Capulus ungaricus . Philip Henry Gosse, Natural History: Mollusca (1854), p. 213 |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Capulus ungaricus | ||||||||||||
| ( Linnaeus , 1758) |
The Hungarian cap , Ungar cap or Hungarian cap screw ( Capulus ungaricus , original combination patella ungarica ) is a worm - type from the family of the cap screw (Capulidae), as commensal on mussels , filtered snails and tube worms in deeper waters of the northeastern Atlantic Ocean can be found .
features
The Hungarian cap has a flat, cap-shaped snail shell , which in adult snails is around 4 cm long and 2.5 cm wide at the mouth of the shell, and 1.5 cm high. The three whorls increase very quickly planospirally and are covered with numerous spiral ribs and fine growth lines. The white shell is covered with a strong, horn-colored periostracum , which forms a border at the mouth of the case. The large, egg-shaped case mouth has a finely sawn edge.
The snail has a short snout and a long, non-retractable pseudoproboscis (false proboscis) formed by the propodium with a dorsal groove. The coat is thick with a double edge, the foot oval and without an operculum.
distribution and habitat
The Hungarian hat is widespread in the northeastern Atlantic Ocean on the southern and western coasts of Great Britain and Norway , in the Skagerrak and Kattegat and in the Mediterranean , but is absent in the central and southern North Sea. It is found below the intertidal zone to the edge of the continental shelf at a depth of 850 m on stones and on mussel shells.
Development cycle
Capulus ungaricus is male and then female up to a casing length of around 4 mm. Instead of the long, curved penis that was initially present behind the right antennae, there is then only a small papilla. Small males mate with large females, in which internal fertilization takes place. The eggs are located in small egg capsules that are attached to a membrane in front of the mother's foot and are guarded by the mother's body. A clutch of around 2.5 mm contains around 0.2 mm eggs, from which well-developed, transparent, gelatinous, almost round Echinospira larvae with a shell diameter of 0.4 mm hatch. These later metamorphose into crawling snails.
nutrition
The snail lives as a commensal on the shells of molluscs , especially scallops and tower snails - often on the common tower snail - where it feeds on pseudofaeces , but also on food particles brought in by the host animals. Since it can withdraw considerable amounts of food from the host animals, it is also considered an ectoparasite ( kleptoparasite ). However, there are also individuals who live on rocks and feed independently as filter feeders. The food is brought to the mouth with the help of the pseudoproboscis.
literature
- Peter J. Hayward, John S. Ryland: Handbook of the Marine Fauna of North-West Europe. Oxford University Press, Oxford 2017. p. 492.
- Alastair Graham : Molluscs: Prosobranch and Pyramidellid Gastropods. Keys and Notes for the Identification of the Species . Linnean Society, London 1988. Family Capulidae, Genus Capulus, Capulus ungaricus (Linné, 1758) , p. 306.
- Marie V. Lebour (1937): The Eggs and Larvae of the British Prosobranchs with Special Reference to those Living in the Plankton. Journal of the Marine Biological Association of the United Kingdom 22 (1), pp. 105-166. Family Capulidae, Genus Capulus, Capulus ungaricus (L.) , p. 143.
- Gunnar Thorson (1965): A neotenous dwarf-form of Capulus ungaricus (L.) (Gastropoda, prosobranchia) commensalistic on Turritella communis Risso. Ophelia 2 (1). S: 175-210. doi: 10.1080 / 00785326.1965.10409599
- Frank Riedel: Origin and evolution of the "higher" Caenogastropoda . Berliner Geoscientific Abhandlungen, Series E, Volume 32, Berlin 2000, p. 41. ISBN 3-89582-077-6 .
Web links
- Family Capulidae - cap snails - Fischhaus Zepkow
- MJ de Kluijver, SS Ingalsuo, RH de Bruyne: Capulus ungaricus (Linné, 1758). Macrobenthos of the North Sea - Mollusca, Marine Species Identification Portal