''Janthina'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of small to medium-sized
pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...
or
planktonic
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...
sea snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
s,
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
* Marine habitats
* Marine life
* Marine pollution
Military
* ...
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
s in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Epitoniidae
Wentletraps are small, often white, very high-spired, predatory or ectoparasitic sea snails, marine gastropod mollusks in the family Epitoniidae.Gofas, S. (2010). Epitoniidae. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollu ...
.
[Gofas, S. (2011). Janthina Röding, 1798. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138092 on 2011-11-01]
Distribution
Species in this genus occur worldwide in
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
, subtropical and warm seas.
Description
These snails are
pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...
and live at the surface of the ocean. Adult snails may not be capable of swimming, and die when they are detached from their rafts; ''
Janthina janthina
''Janthina janthina'' is a species of holoplanktonic sea snail, a marine gastropod mollusk in the family Epitoniidae. Its common names include violet sea-snail, common violet snail, large violet snail and purple storm snail.
Distribution
This ...
'' larvae, however, actively swim in the water column.
The adult snails prey upon (and live near to) one of several species of pelagic animals loosely known as jellyfish. More specifically they eat the
medusae
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...
of free-swimming
Cnidaria
Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter.
Their distinguishing feature is cnidocytes, specialized cells that th ...
, in particular the genus known as "by-the-wind sailors", ''
Velella
''Velella'' is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is ''Velella velella'', a cosmopolitan free-floating hydrozoan that lives on the surface of the open ocean. It is commonly known by the names sea raf ...
''.
The snails are able to float securely because they create a raft of clear
chitin
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...
around air bubbles formed near the ocean surface. They anchor to this raft using their
foot
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
.
The snails do not have an
operculum.
These snails are frequently washed ashore during storms.
The common names for this genus derive from the light purple or violet color of the shells and the violet-colored bodies. The other genus in the family, ''
Recluzia
''Recluzia'' is a genus of small to medium-sized pelagic or planktonic sea snails, marine gastropod molluscs in the family Epitoniidae.MolluscaBase (2019). MolluscaBase. Recluzia Petit de la Saussaye, 1853. Accessed through: World Register of Ma ...
'', has olive-tan colored shells.
Species
The five extant species of the genus ''Janthina''
File:Janthina exigua 01.jpg, ''Janthina exigua''
File:Janthina globosa 01.JPG, ''Janthina globosa''
File:Janthina janthina 01.JPG, ''Janthina janthina''
File:Janthina pallida 01.JPG, ''Janthina pallida''
File:Janthina umbilicata 01.jpg, ''Janthina umbilicata''
This genus has accumulated a very large number of species names over the centuries. Most of the names that have been given are in fact
synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
s of just a few species which have world-wide distributions in tropical waters. Experts disagree about some details of the synonymy.
Species within the genus ''Janthina'' include:
[Gofas, S. (2009). ''Janthina'' Röding, 1798. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2009) World Marine Mollusca database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138092 on 2010-05-16]
* † ''
Janthina chavani''
(Ludbrook, 1978)
* ''
Janthina exigua
''Janthina exigua'', also known as the dwarf janthina, is a species of small holoplanktonic sea snail, a marine gastropod mollusk in the family Epitoniidae, the violet snails or purple storm snails.MolluscaBase (2019). MolluscaBase. Janthina exig ...
''
Lamarck
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolog ...
, 1816 - dwarf janthina
* ''
Janthina globosa''
Swainson, 1822
* ''
Janthina janthina
''Janthina janthina'' is a species of holoplanktonic sea snail, a marine gastropod mollusk in the family Epitoniidae. Its common names include violet sea-snail, common violet snail, large violet snail and purple storm snail.
Distribution
This ...
''
(Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
, 1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...
)
*† ''
Janthina krejcii''
Beu, 2017
* ''
Janthina pallida''
W. Thompson, 1840
* † ''
Janthina typica''
(Bronn, 1861)
* ''
Janthina umbilicata''
d'Orbigny, 1841
;Species brought into synonymy:
* ''Janthina affinis''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina africana''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina alba''
Anton, 1838: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina balteata''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina bicolor''
Menke, 1828: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina bicolor''
O. G. Costa, 1830: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina bifida''
Nuttall, 1850: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina britannica''
Forbes & Hanley, 1853: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina capreolata''
Montrouzier, 1860: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina carpenteri''
Mörch, 1860: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina casta''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina coeruleata''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina communis''
Lamarck, 1822: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina contorta''
Carpenter, 1857: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina costae''
Mörch, 1860: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina decollata''
Carpenter, 1857: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina depressa''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina elongata''
ic synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina fibula''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina fragilis''
Lamarck, 1801: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina globosa''
Blainville, 1822: synonym of ''Janthina umbilicata''
d'Orbigny, 1840
* ''Janthina grandis''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina incisa''
Philippi, 1848: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina involuta''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina iricolor''
Reeve, 1858: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina jehennei''
(Petit de la Saussaye, 1853): synonym of ''
Recluzia jehennei''
Petit de la Saussaye, 1853
* ''Janthina laeta''
Monterosato, 1884: synonym of ''Janthina pallida''
W. Thompson, 1840
* ''Janthina megastoma''
A. Adams, 1861: synonym of ''Janthina umbilicata''
d'Orbigny, 1840
* ''Janthina nana''
Gray, 1842: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina nitens''
Menke, 1828: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina nitida''
A. Adams, 1861: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina orbignyi''
Mörch, 1860: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina patula''
Philippi, 1844: synonym of ''Janthina pallida''
W. Thompson, 1840
* ''Janthina payraudeaui''
Locard, 1900: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina penicephela''
Peron, 1824: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina planispirata''
A. Adams & Reeve, 1848: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina prolongata''
Blainville, 1822: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina rosea''
Anton, 1838: synonym of ''Janthina pallida''
W. Thompson, 1840
* ''Janthina roseala''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina roseola''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina rotundata''
Dillwyn, 1840: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina smithiae''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina splendens''
Monterosato, 1884: synonym of ''Janthina globosa''
Swainson, 1822
* ''Janthina striata''
Montrouzier, 1860: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina striolata''
A. Adams & Reeve, 1848: synonym of ''Janthina pallida''
W. Thompson, 1840
* ''Janthina striulata''
Carpenter, 1857: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina trochoidea''
Reeve, 1858: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina vinsoni''
Deshayes, 1863: synonym of ''Janthina exigua''
Lamarck, 1816
* ''Janthina violacea''
Röding, 1798: synonym of ''Janthina janthina''
(Linnaeus, 1758)
* ''Janthina vulgaris''
Gray, 1847: synonym of ''Janthina janthina''
(Linnaeus, 1758)
References
* Laursen, D. 1953. ''The genus Ianthina: A monograph''. Dana Report 38: 1-40, pl. 1
External links
* https://www.biodiversitylibrary.org/page/16230659 Röding P.F. (1798). Museum Boltenianum sive Catalogus cimeliorum e tribus regnis naturæ quæ olim collegerat Joa. Fried Bolten, M. D. p. d. per XL. annos proto physicus Hamburgensis. Pars secunda continens Conchylia sive Testacea univalvia, bivalvia & multivalvia. Trapp, Hamburg. viii, 199 pp]
Montfort_P._[Denys_de_(1808-1810)._Conchyliologie_systématique_et_classification_méthodique_des_coquilles._Paris:_Schoell._Vol._1:_pp._lxxxvii_+_409_[1808.html" ;"title="enys de">Montfort P. [Denys de
(1808-1810). Conchyliologie systématique et classification méthodique des coquilles. Paris: Schoell. Vol. 1: pp. lxxxvii + 409 [1808">enys de">Montfort P. [Denys de
(1808-1810). Conchyliologie systématique et classification méthodique des coquilles. Paris: Schoell. Vol. 1: pp. lxxxvii + 409 [1808 Vol. 2: pp. 676 + 16 ]
Gistel, Johannes [Nepomuk Franz Xaver (1848). Naturgeschichte des Tierreichs: für höhere Schulen.
ext book 1-216, i-xvi, Plates 1-32. Stuttgart. Scheitlin & Krais.]
Mörch, O. A. L. (1860). Matériaux pour servir à l'histoire de la famille des Janthines. Journal de Conchyliologie. 8 (3): 261-285Iredale, T. (1929). Queensland molluscan notes, no. 1. Memoirs of the Queensland Museum. 9(3): 261-297, pls 30-31Kaim, A.; Tucholke, B. E.; Warén, A. (2012). A new Late Pliocene large provannid gastropod associated with hydrothermal venting at Kane Megamullion, Mid-Atlantic Ridge. Journal of Systematic Palaeontology. 10(3): 423-433Beu A.G. (2017). Evolution of Janthina and Recluzia (Mollusca: Gastropoda: Epitoniidae). Records of the Australian Museum. 69(3): 119-222Gary Rosenberg's Malacolog 4.1.1 info on this genus in the Western Atlantic
{{Taxonbar, from=Q3168326
Epitoniidae