Atlantidae
| Atlantidae | ||||||||||||
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Atlanta sp. |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Atlantidae | ||||||||||||
| Rank , 1829 |
The Atlantidae are a family of the Pterotracheoidea (formerly also Heteropoda) within the snail . They have a pelagic way of life and live predatory on snails from the group of Thecosomata .
features
The family includes small forms (approx. 1 cm) with a right-hand wound, transparent and flat case with a keel. It is somewhat reminiscent of a housing from Planorbis . Housing and keel can be mineralized ( Atlanta ), or just the housing ( Protatlanta ) or housing and keel are not mineralized ( Oxygurus ). In contrast to the representatives of the other families of the Pterotracheidae, they can still completely withdraw into the housing and close the housing opening with an operculum . The soft body is gelatinous and translucent. The animals swim on their backs with the help of the foot that has been transformed into a fin. The head has a snout and a pair of long tentacles that sit in front of the eyes. The eyes are highly developed and sit slightly above the surface of the head. You have a lens. A muscular suction cup sits on the webbed foot to hold the prey. The long radula has 7 elements per transverse row; a central tooth as well as a lateral tooth and two marginal teeth on either side of the central tooth. The animals are of separate sex. The males transfer the sperm packages with the mating organ into the mantle cavity. The development takes place via a planktotrophic (plankton-eating) Veliger larva.
Lifestyle and diet
The representatives of the family live exclusively pelagic in the open sea. They prefer to feed on other plankton snails ( Thecosomata or Pteropoda). The prey is grasped with the help of the tentacles and held on the foot with the help of the suction cup, while the animal bites pieces of the prey with the help of the radula.
Occurrence
The species of the superfamily live worldwide in the upper 200 meters of the warmer seas. Many species undertake daily migrations in the water column, from shallow water during the day to deeper water layers during the night. The animals are heavier than water, i. H. During the day they swim permanently so as not to slowly sink into the water column. In the evening, the animals then excrete threads of mucus that keep the animals floating in the water column.
Systematics
There are currently three types of family:
- Atlanta Reader, 1817
- Oxygyrus Benson, 1835
- Protatlanta Tesch, 1908
literature
- Philippe Bouchet & Jean-Pierre Rocroi: Part 2. Working classification of the Gastropoda . In: 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
- Winston Ponder & David Lindberg: Towards a phylogeny of gastropod molluscs; an analysis using morphological characters . In: Zoological Journal of the Linnean Society. 119: 83-265, London 1997 ISSN 0024-4082
- Roger R. Seapy: The pelagic family Atlantidae (Gastropoda: Heteropoda) from Hawaiian waters: a taxonomic survey. In: Malacologia. 32: 107-130, Ann Arbor, Michigan 1990 ISSN 0076-2997
Web links
Individual evidence
- ↑ Catalog of Life - 2019 Annual Checklist: Taxonomic Tree. Retrieved September 18, 2019 .