Great snail
| Great snail | ||||||||||||
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Case and operculum of Syrinx aruanus |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Syrinx | ||||||||||||
| Röding , 1798 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Syrinx aruanus | ||||||||||||
| ( Linnaeus , 1758) |
The syrinx aruanus ( Syrinx aruanus ) is a snail from the family of turbinellidae that the Indian Ocean is common, and the only species of the genus Syrinx . With a housing length of over 90 cm, it is the largest snail in the world. It feeds mainly on large poly bristles .
features
The very large, right-hand wound , spindle-shaped snail shell of Syrinx aruanus , which in adult snails reaches a length of about 60 cm, sometimes over 90 cm, has a moderately high to high thread and a long, thin, straight and open siphon channel . The approximately 5 embryonic passages at the apex, the approximately 2.5 cm high protoconch , which are mostly lost in older snails, are very high and tower-like. The whorls of the thread are oblique with an angled, projecting edge, which is in some cases occupied with a series of low, rounded knots, and above it a straight or slightly concave, inclined surface. The body is slightly bulbous and angled at the base. The entire surface of the case is covered with screw-like straps, some of which appear a bit rougher on the body. The wide, egg-shaped housing mouth is smooth inside the outer and inner edge. The columella is not folded. The housing has an elongated umbilical slot. The outside and inside of the snail shell are solid apricot to creamy yellow. The thick periostracum is brown.
The snail has a long, thin and extendable trunk (proboscis) with which it can penetrate up to 25 cm deep into the tubes of sedentary polychaetes.
distribution
The great elephant snail is native to the northern coasts of Australia , the southern coast of New Guinea and around the Moluccas .
habitat
The large elephant snail lives on sandy subsoil in the intertidal zone and below to depths of about 30 m, where tube- dwelling polychaetes , which form their main food, live in large numbers.
food
Syrinx aruanus eats polychaetes of the genera Polyodontes (including Polyodontes australiensis , family Acoetidae ), Laoimia ( Loimia ingens , Loimia ochracea , family Terebellidae ) and Diopatra ( Onuphidae ). On the one hand, the snail was observed in situ eating these worms, and on the other hand, setae from the snail's feces were examined. The polychaetes eaten by the snail reach considerable body lengths, in the genus Polyodontes sometimes over a meter.
Life cycle
Like other new snails, Syrinx aruanus is segregated. The male mates with the female with his penis . The female attaches egg containers about 15 cm in size, which consist of several egg capsules, to rocks, mollusc shells or corals. The development of the snail takes place in the egg capsule, so that finished juvenile snails hatch, which have an approximately 2.5 cm large tower-like shell with 5 turns. Since there are no pelagic Veliger larvae, the species can only slowly spread or repopulate areas devastated by overfishing.
Importance to humans
Syrinx aruanus is collected for its case, which is traded as jewelry. In addition, the meat is eaten. Due to overfishing , the snail population and the average shell size have decreased in recent years.
The natives of Australia on the Pennefather River in Queensland traditionally made crescent-shaped nose studs for men ( imina ) from the shell of Syrinx aruanus . Instead, the women wore plugs made of grass. The housing must have been in the water for processing. A rib-shaped piece of the shell was used next to the seam around the body. The snail shell traditionally also serves as a water container.
Systematics
The snail species was described by Carl von Linné as Murex aruanus . The name of the genus Syrinx , which is monotypical according to today's understanding , is mentioned for the first time by Peter Friedrich Röding in the catalog of the Conchyliensammlung of Joachim Friedrich Bolten , but here as the genus Syrinx , the Sprütze, with 19 species ( Gmelin listed under Murex ), including the first species S Aruana , the Aruan's horn. Another synonym is Fusus proboscidiferus , in whose name Jean-Baptiste de Lamarck named the long trunk of the snail in 1822 (the "trunk-bearing spindle"). The approximately 2.5 cm long, tower-like protoconch of the newly hatched snails differs so much from the house of the adult animals that George Washington Tryon considered this to be a separate species in 1887 and described it under the name Cerithium brazieri .
Trivia
With a shell length of over 90 cm, the great snail is the largest known snail on earth. Only one species of sea hare living on the Californian Pacific coast , the nudibranch Aplysia vaccaria , reaches body lengths similar to this of just under one meter .
literature
- John D. Taylor, Emily A. Glover: Food of giants - field observations on the diet of Syrinx aruanus (Linnaeus, 1758) (Turbinellidae) the largest living gastropod. In: FE Wells, DI Walker, DS Jones (Eds.): The Marine Flora and Fauna of Dampier, Western Australia . Western Australian Museum, Perth 2003, pp. 217–224 ( online (PDF) ( memento of March 26, 2015 in the Internet Archive )).
Web links
- Turbinellidae: Syrinx aruanus (Linnaeus, 1758) . From: JM Poutiers: Gastropods . In: Kent E. Carpenter, Volker H. Niem (eds.): FAO Species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 1: Seaweeds, corals, bivalves and gastropods. Food and Agriculture Organization of the United Nations, Rome, 1998. p. 605.
- Queensland Museum: Syrinx - the world's largest snail - Syrinx aruanus
- Fischhaus Zepkow: Family Turbinellidae - Vases & Chanks
Individual evidence
- ^ Walter Edmund Roth (1910): "North Queensland etnography". Records of the Australian Museum, Sydney, 8 (1): pp. 1–106. P. 30.
- ^ S. Peter Dance: Shells . Dorling Kindersley , London 1992. 256 pp. ISBN 0-86318-811-7 . Page 141.
- ↑ Carolus Linnaeus : Systema Naturae. 10th ed., Lars Salvius: Stockholm 1758, p. 746, 290. Murex , p. 753, 484. Murex aruanus. M. testa patulo-caudata, spira spinoso-coronata. Habitat ad Novam Guineam.
- ↑ Peter Friedrich Röding (1798): Museum Boltenianum, sive, Catalogus cimeliorum e tribus regnis naturae quae olim collegerat Joa. Fried. Bolten : pars secunda continens conchylia sive testacea univalvia, bivalvia et multivalvia . Trappi, Hamburg, viii. + 199 p. Reprinted by the British Museum , London 1906. Pages 121f., Ark 63, Syrinx. The sprayer. 1560 1 S. Aruana. The Aruan's Horn. Gmel. Murex aruanus, sp. 71. One of extraordinary size, the other smaller, but of excellent beauty .
- ^ Jean-Baptiste de Lamarck (1822): Histoire naturelle des Animaux sans Vertèbres . Verdiere, Paris 1822. 711 pp., 126.
- ↑ George Washington Tryon (1887): Manual of Conchology, structural and systematic, with illustrations of the species . Volume 9. Solariidae (by William B. Marshall), Ianthinidae, Trichotropidae, Scalariidae, Cerithiidae, Rissoidae, Littorinidae . 488 pp., 71 plates.