Busycon carica

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Busycon carica
Busycon carica retracted into the housing

Busycon carica retracted into the housing

Systematics
Order : Sorbeoconcha
Partial order : New snails (Neogastropoda)
Superfamily : Buccinoidea
Family : Buccinidae
Genre : Busycon
Type : Busycon carica
Scientific name
Busycon carica
( Gmelin , 1791)
Housing from Busycon Carica
Egg clutches from Busycon carica
Busycon carica ssp. eliceans

Busycon carica , near Röding the prickly fig , is a very large species of snail from the Buccinidae family thatlivesin the western Atlantic on the coast of North America .

features

The right-hand wound, very strong and thick, pear-shaped snail shell of Busycon carica , which can be up to 30 cm long in fully-grown snails, has a low thread, a long and wide body circumference and a long pear-shaped housing mouth with a simple, sharp edge that goes into one long, open siphon channel. The up to 8 angular passages that are indented at the top are occupied by a row of knots on the edge towards the apex, which on the last passages become widely protruding scale-shaped spines. The thick, horny, dark brown operculum is egg-shaped. The surface of the housing is yellowish gray on the outside and orange brown on the inside. Axially extending purple-brown stripes can be seen especially in young animals. The Columella is bright rose-red to orange-red. In older animals, the outer color of the shell fades.

The snail itself is dark brown to black. The Sipho hardly protrudes from the canal in the active snail.

Busycon carica is very similar to its left-handed sister species, the lightning snail or left-handed fig ( Busycon perversum , also known as Busycon contrarium and Busycon sinistrum ), from which it differs in particular in the direction of the winding of the shell.

Occurrence

Busycon carica is found in the western Atlantic on the coast of North America from Cape Cod southwards, on the Florida coast and in the northern part of the Gulf of Mexico .

It is very common in the intertidal zone and around estuaries .

Life cycle

Like other new snails, Busycon carica is separate sexes, with the females being significantly larger than the males. There are slightly more females than males in deeper water and up to nine times more females in the intertidal zone. Growth strips on the operculum show that the females are growing faster. In Georgia , males reach sexual maturity with a shell length of 8.5 to 9 cm at the age of about 4 years, while females with a shell length of about 10 cm at the age of about 6 years. In the period from March to April, the males mate the females with their penis . From April onwards, the females lay their egg cords with about 40 to 157 disc-shaped egg capsules, in which there are viable eggs and sterile nursing eggs. Young animals of a clutch can have several fathers. A female puts 1 to 23 capsules a day. The clutches are anchored in the sand and separate when the juvenile snails hatch. The development of the Veliger stage takes place in the egg capsule, so that, depending on the temperature, finished snails hatch several months after oviposition, in Georgia essentially until the beginning of June. Up to 100 juveniles hatch from one egg capsule, which have a housing about 3 to 7 mm (on average about 6 mm) long. Most snails develop into capsules in the middle of the egg cord. There are roughly the same number of male and female juvenile snails within a clutch.

nutrition

Busycon carica is a carnivore that feeds primarily on mussels . The snail presses open the shell halves of the mussel with its foot. If this does not succeed, it breaks open a piece of the shell or many pieces of shell one after the other with its housing edge. Then it leads the proboscis to the meat of the prey, which is minced with the help of the radula . Breaking open the mussel shell often leads to damage to the shell of the snail, so that it then has to use energy to repair it.

Busycon carica eats strong, thick-shelled mussels such as clams , including Mercenaria mercenaria and Chione cancellata , but also agile types of mussels such as scallops , such as the Caribbean scallop Argopecten irradians . The snail is the main enemy of scallops , especially in deeper water where there is limited food competition from seagulls . A large, 17 to 25 cm long snail eats a fully grown clam 5 to 8 cm in length about every four days. Seagrass meadows of Zostera marina or Halodule wrightii offer both scallops and clams protection against the predatory snail, while algae growth on the mussel shell does not present an obstacle to the snails.

Human use and exposure

Busycon carica is collected for its meat and casing and is also used commercially. Due to overfishing , the fishery yields have decreased significantly in recent years. Decimated stocks can only regenerate slowly because the snail grows slowly and females, which are significantly larger than males, are preferred. Size limitations of 10 cm housing length for fishing hit the sexually mature females exactly. Since there are no pelagic Veliger larvae, the repopulation of empty habitats is also slowed down.

Individual evidence

  1. ↑ 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 pp. Reprinted by the British Museum , London 1906. Page 149, Ark 77, Busycon. 1866 1 B. Muricatum. The prickly fig, gmelin , murex carica .
  2. ↑ a b Alan J. Power, Christina J. Sellers, Randal L. Walker: Growth and sexual maturity of the Knobbed Whelk, Busycon carica (Gmelin, 1791), from a commercially harvested population in coastal Georgia (PDF; 1.8 MB ) . Occasional Papers of the University of Georgia Marine Extension Service, Vol. 4, Savannah (Georgia) 2009.
  3. ^ R. Christopher Prescott (1990): Sources of predatory mortality in the bay scallop Argopecten irradians (Lamarck): interactions with seagrass and epibiotic coverage . Journal of Experimental Marine Biology and Ecology 144 (1), pp. 63-83. doi : 10.1016 / 0022-0981 (90) 90020-D
  4. ^ CH Peterson (1982): Clam predation by whelks (Busycon spp.): Experimental tests of the importance of prey size, prey density, and seagrass cover . Marine Biology 66 (2), pp. 159-170. doi : 10.1007 / BF00397189 .

literature

  • Robert Tucker Abbott, Percy A. Morris: A Field Guide to Shells: Atlantic and Gulf Coasts and the West Indies . Houghton Mifflin Harcourt, Boston 2001. Knobbed Whelk, Busycon carica (Gmelin, 1791) : pp. 227f. ISBN 978-0-618-16439-4 .
  • Edward E. Ruppert, Richard S. Fox: Seashore Animals of the Southeast: A Guide to Common Shallow-Water Invertebrates of the Southeastern Atlantic Coast . University of South Carolina Press, Columbia (South Carolina) 1988. Busycon : pp. 112f.
  • John W. Tunnell, Jean Andrews, Noe C Barrera, Fabio Moretzsohn: Encyclopedia of Texas Seashells: Identification, Ecology, Distribution, and History . Texas A&M University Press, College Station (Texas) 2010. 512 pp. Busycon : p. 222ff.
  • Hulda Magalhaes (1948): An Ecological Study of Snails of the Genus Busycon at Beaufort, North Carolina . Ecological Monographs 18 (3), pp. 377-409. ( jstor )
  • Wilhelm Kobelt : The genera Pyrula and Fusus; together with Ficula, Bulbus, Tudicla, Busycon, Neptunea and Euthria. Systematic Conchylia Cabinet. Verlag von Bauer & Raspe, Nuremberg 1881. pp. 45–53. V. genus. Busycon Bolten. P. 50f. No. 4. Busycon caricum Gmelin sp.

Web links

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