Coastal snails

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Coastal snails
Ellobium chinense Pfeiffer, 1856

Ellobium chinense Pfeiffer, 1856

Systematics
Class : Snails (gastropoda)
Subclass : Heterobranchia
Order : Pulmonates
Subordination : Eupulmonata
Superfamily : Ellobioidea
Family : Coastal snails
Scientific name
Ellobiidae
H. Adams & A. Adams in Pfeiffer , 1854

The coastal snails (Ellobiidae) are a family of snails from the order of the pulmonate snails (Pulmonata), which predominantly colonize habitats between land and sea in the tropics. Most species live there above the splash line, in mangroves and beach areas.

features

The representatives of this family have a spindle-shaped, egg-shaped-conical, usually right-hand wound housing (exception : Blauneria ). It is smooth or has spiral lines and a brown periostracum . The mouth is elongated, rounded on the abdomen, pointed on the back. The mouth seam is z. Partly strong lipped reinforced. Strong lamellae are formed on the inner lip, while the outer lip is sharp-edged or slightly bent and often toothed. The inner coils are mostly resorbed (exceptions: the genera Pedipes and Creedonia ). The Protoconch is heterostrophic, ie it is initially left-wound and then turns rightward.

The animals can completely withdraw into the housing. The head is separated from the foot by a transverse pit, into which a mucous gland opens. An operculum is only created in the embryonic stage and is later thrown off. The mouth is T-shaped. There is only one pair of cylindrical retractable tentacles. The eyes are sessile in the center of the tentacle bases. The foot is long, bluntly rounded at the front, gradually tapering or double-pointed at the back. The sole is often divided across. The breathing hole (pneumostome) is on the right side near the anal opening. The radula is long and wide with numerous teeth in a transverse row. The central tooth is symmetrical, the lateral teeth asymmetrical. They get smaller towards the edge and gradually or abruptly change into the edge teeth.

The animals are hermaphrodites. The hermaphrodite is acinar and deeply embedded in the digestive gland or leaf-shaped and covers z. T. the liver. The hermaphroditic duct (ductus hermaphroditicus) is strongly intertwined, the protein gland (albumin gland) is whitish. The posterior mucous gland is severely twisted, the anterior mucous gland straight. The prostate covers the outer ducts (exception: subfamily Melampinae). The fertilization chamber follows the posterior mucous gland and sits at the end of the egg duct before the fallopian tubes and sperm duct separate. The seminal vesicle sits on a stem that opens into the vagina. The female genital opening is located in the middle between the breathing hole and the midline and in front of the union of the mantle with the neck. The male sex orifice sits at the right corner of the head pit and the right tentacle. A skin fold, the so-called semen pit, runs from near the female genital opening to the male genital opening. But it is only functional in the genus Pythia . In all other genera, the vas deferens is embedded in the neck skin. The spermatic duct separates from the skin near the male genital opening and opens into the penis at the rear end of the penis.

Geographical distribution and habitat

The Ellobiidae are distributed worldwide, but occur mainly in the tropical regions of the world. They inhabit habitats along the seashore, mangrove swamps, the tidal zone above the splash zone, pebble and rocky beaches under stones and crumbling wood. In non-tropical regions they live mainly in euryhyaline habitats, ie with strongly fluctuating salt contents, such as salt marshes and rocky coasts.

Taxonomy and systematics

The taxon was basically set up by Jean-Baptiste de Lamarck in 1809 under the common name "Les Auriculacées". John Gray Latinized the name to Auriculidae. In 1854 Henry Adams and Arthur Adams proposed the name Ellobiidae, which Pfeiffer published as a synonym. Auriculidae was the name for this family until around 1920. Thereafter, in the further course of the processing history, the name Ellobiidae prevailed as a name for this group, mainly due to the fact that the eponymous genus Auricula Lamarck, 1799, is a younger synonym of Ellobium Röding, 1798.

The family Ellobiidae Adams & Adams in Pfeiffer, 1854 (1809) is divided into six subfamilies by Bouchet & Rocroi (2005):

The (sixth) subfamily of the dwarf horn snails (Carychiinae Jeffreys, 1830) in Bouchet & Rocroi (2005) is mostly regarded as a separate family today.

supporting documents

literature

  • Martins, António de Frias 1997: Relationships within the Ellobiidae. In: Taylor, John (Ed.): Origin and evolutionary radiation of the Mollusca, pp. 285-295, Oxford University Press.

Individual evidence

  1. ↑ Bouchet, Philippe & Jean-Pierre Rocroi 2005: Part 2. Working classification of the Gastropoda. Malacologia, 47: 239-283, Ann Arbor ISSN  0076-2997
  2. ↑ Weigand, Alexander M., Adrienne Jochum, Markus Pfenninger, Dirk Steinke, & Annette Klussmann-Kolb 2011: A new approach to an old conundrum - DNA barcoding sheds new light on phenotypic plasticity and morphological stasis in microsnails (Gastropoda, Pulmonata, Carychiidae ). - Molecular Ecology Resources 11: 255-265 doi : 10.1111 / j.1755-0998.2010.02937.x .
  3. ↑ Fauna Europaea: Family Carychiidae
  4. ^ Molluscs of central Europe - Familia Carychiidae

Web links

Commons : Ellobiidae  - collection of images, videos and audio files