Olive snail
Black olive snail ( Oliva vidua )
The olive snails ( Olividae ) are a diverse family exclusively marine, predator live snails. They live mainly in the warmer seas. The oldest members of this family are occupied for the Upper Cretaceous.
Features
The housing of the olive snails are, as the name implies, olive-shaped to rounded hochkonisch. The surface is low ornamented, usually glossy porcelain-like and often provided with a color pattern. Adult size of the casing is about 0.7 to 12 cm. The foot is usually very large, extended the Propodium into two lobes, the side of the foot to include two additional flaps on. With the propodialen and the lateral lobes of the foot for the animal to almost completely envelop and move quickly in loose sediment or just below the sediment surface. The rasp is relatively short with three elements per transverse row. The animals are dioecious. The egg capsules are attached to hard substrate, or simply placed on the soft substrate. They contain from about 150 to 200 eggs. The ontogenetic development may be through a plankton -feeding veliger larva, but also directly, that is, from the egg white egg capsule slips extend directly the finished cub.
Way of life
The olive snails are found in all oceans today. However, the focus of the distribution with the highest diversity is clearly in the warmer seas. They are almost invariably soft bottom dwellers ( primarily sand). They live here mostly in the sediment, they can plow through literally using the large foot. The siphon is held for breathing on the sediment surface and also allows the localization of prey. All olive snails are predators that attack fairly large prey for T.. The prey consists primarily of bristle worms and other molluscs are overwhelmed with the large foot. The muscular foot with the big Propodium allows some species from the sediment surface to jump and swim a short distance. The vast majority of species live in shallow water. A few species are also migrated to the deep sea, where they were found in up to 4400 m.
System
The family is subdivided according to Bouchet & Rocroi (2005) into three subfamilies:
- Olivinae Latreille, 1825
- Ancillariinae Swainson, 1840
- † Vanpalmeriinae Adegoke, 1977
Some authors is also a subfamily Agaroninae Olsson, 1956 excreted, but Bouchet & Rocroi list as a synonym of the subfamily Olivinae. The questions asked in previous publications in the Olividae family subfamilies dwarf olive shells ( Olivellinae ) and apparent olive snails ( Pseudolivinae ) are now managed as separate families. The Olividae family is still expected from Ponder & Lindberg (1997) to the superfamily Muricoidea. Bouchet & Rocroi (2005) lead them already as a separate superfamily with the families Olividae and Olivellidae Troschel, 1869. Apparent olive snails ( Pseudolividae ) form, however, together with the Ptychatractidae the superfamily Pseudolivoidea.