''Clione limacina'', known as the naked sea butterfly, sea angel, and common clione, is a

sea angel Sea angels ( clade Gymnosomata) are a large group of small free-swimming sea slugs, not to be confused with Cnidarians (Jellyfish and other similar creatures), classified into six different families. They are pelagic opisthobranchs in the cla ...

(pelagic

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary time ...

) found from the surface to greater than depth.Gofas, S. (2012). ''Clione limacina''. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=139178 on 2012-07-23 It lives in the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

and cold regions of the

North Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe an ...

. It was first described by Friderich Martens in 1676 and became the first gymnosomatous (without a shell) " pteropod" to be described.

Subspecies

* ''Clione limacina australis'' ( Bruguière, 1792)Gofas, S. (2011). ''Clione limacina''. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=139178 on 2011-01-29 * ''Clione limacina limacina'' (Phipps, 1774)

Distribution

''Clione limacina'' is found in cold waters of the Arctic Ocean and North Atlantic Ocean, ranging south at least to the Sargasso Sea. There are three other species in the genus, which formerly were included in ''C. limacina'' (either as subspecies, variants or subpopulations). These are '' C. elegantissima'' of the cold North Pacific (at least north to the

Gulf of Alaska The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east ...

; the Beaufort Sea is inhabited by ''C. limacina''), '' C. okhotensis'' of the

Okhotsk Sea The Sea of Okhotsk ( rus, Охо́тское мо́ре, Ohótskoye móre ; ja, オホーツク海, Ohōtsuku-kai) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands ...

(where it overlaps with ''C. elegantissima''), and '' C. antarctica'' of Antarctic waters. Clione limacina by NOAA

Description

There are two subspecies that differentiate in body length. The northern subspecies lives in colder water, matures at and can reach a size of .Kallevik, I.H.F. (2013).
Alternative prey choice in the pteropod ''Clione limacina'' (Gastropoda) studied by DNA-based methods.
'' Biology Field of study - Arctic Marine Ecology and Resource Biology. Bio-3950 (60 ECT). The University Center in Svalbard. This makes it by far the largest

. In comparison, the size of the southern subspecies is , ''C. elegantissima'' is up to , ''C. okhotensis'' up to , and ''C. antarctica'' up to . The

neurobiology Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...

of this pteropod has been studied in detail.

Ecology

''Clione limacina'' inhabits both the

epipelagic The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological proc ...

and

mesopelagic The mesopelagic zone (Greek μέσον, middle), also known as the middle pelagic or twilight zone, is the part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is defined by light, and begins at ...

regions of the water column.

Feeding habits

Adults feed in a predator-prey relationship almost exclusively on the

sea butterflies Sea butterflies, scientific name Thecosomata (thecosomes, "case / shell-body"), are a taxonomic suborder of small pelagic swimming sea snails. They are holoplanktonic opisthobranch gastropod mollusks. Most Thecosomata have some form of calcifi ...

of the genus '' Limacina'': on ''

Limacina helicina ''Limacina helicina'' is a species of small swimming planktonic sea snail in the family Limacinidae, which belong to the group commonly known as sea butterflies ( Thecosomata). ''Limacina helicina'' is a keystone species of mesozooplankton in ...

'' and on '' Limacina retroversa''.Lalli C. M. & Gilmer R. W. (1989). ''Pelagic Snails. The biology of holoplanktonic gastropod molluscs.'' Stanford University Press: Stanford, California
page 188
Böer M., Gannefors C., Kattner G., Graeve M., Hop H. & Falk-Petersen S. (2005). "The Arctic pteropod ''Clione limacina'': seasonal lipid dynamics and life-strategy". ''Marine Biology'' 147(3): 707–717. . The feeding process of ''Clione limacina'' is somewhat extraordinary. The buccal ("mouth") apparatus consists of three pairs of buccal cones. These tentacles grab the shell of ''Limacina helicina''. When the prey is in the right position, with its shell opening facing the radula of ''Clione limacina'', it then grasps the prey with its

chitinous 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 ...

hooks, everted from hook sacs. Then it extracts the body completely out of its shell and swallows it whole. Adult ''Limacina'' are absent for much of the year, leaving ''C. limacina'' without access to their main food source. A study of 138 ''C. limacina'' during a period without adult ''Limacina'' found that the stomachs of 24 contained remains of amphipods and 3 contained remains of

calanoid Calanoida is an order of copepods, a group of arthropods commonly found as zooplankton. The order includes around 46 families with about 1800 species of both marine and freshwater copepods between them. Description Calanoids can be distinguish ...

s. This temporary prey change may allow them to survive in periods of starvation, although the species can survive for one year without food.Böer M., Graeve M. & Kattner G. (2006). "Exceptional long-term starvation ability and sites of lipid storage of the Arctic pteropod ''Clione limacina''". ''Polar Biology'' 30(5): 571–580. . Under such exceptional starvation in the laboratory the length of slugs have decreased on average from . The earliest larvae stages of ''C. limacina'' feed on phytoplankton, but from the later laval stage this changes to ''Limacina''. The development of these two species is parallel and small ''C. limacina'' feed on ''Limacina'' of a size, while large ''C. limacina'' avoid small ''Limacina'' (including its larvae).

Life cycle

In Svalbard, the

life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring * Life-cycle hypothesis ...

of ''C. limacina'' appears to be at least 2 years. It is a hermaphrodite and observations suggest this is simultaneous. It breeds during the spring and summer, and the eggs are about . ''Clione limacina'' is a prey of planktonic feeders, such as the baleen whales, which historically led to sailors naming it "whale-food". Some fishes are also its predators. For example, the Chum Salmon, ''

Oncorhynchus keta The chum salmon (''Oncorhynchus keta''), also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus '' Oncorhynchus'' (Pacific salmon) native to the coastal rivers of the North Pacific and the Beringian A ...

'', is a major predator of sea angels.

References

This article incorporates CC-BY-SA-3.0 text from the reference

* http://www.seaslugforum.net/factsheet/cliolima accessed 5 January 2010 * Boas J. E. V. (1888). "Spolia Atlantica. Bidrag til Pteropodernes. Morfologi og Systematik samt til Kundskaben om deres geografiski Udbredelse". ''Det Kongelige Danske videnskabernes selskabs skrifter''. København, serie 6, number 4: 1–231. Page
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Plate 7
figure 101–103. * Abbott, R.T. (1974). ''American Seashells''. 2nd ed. Van Nostrand Reinhold: New York, NY (USA). 663 pp * Backeljau, T. (1986). ''Lijst van de recente mariene mollusken van België ist of the recent marine molluscs of Belgium'' Koninklijk Belgisch Instituut voor Natuurwetenschappen: Brussels, Belgium. 106 pp. * Conover R. J. & Lalli C. M. (1972). "Feeding and growth in ''Clione limacina'' (Phipps), a pteropod mollusc". ''

Journal of Experimental Marine Biology and Ecology The ''Journal of Experimental Marine Biology and Ecology'' is a peer-reviewed bimonthly journal which publishes work on the biochemistry, physiology, behaviour, and genetics of marine plants and animals in relation to their ecology. According to th ...

'' 9(3): 279–302. . * Falk-Petersen S., Sargent J. R., Kwasniewski S., Gulliksen B. & Millar R.-M. (2001). "Lipids and fatty acids in ''Clione limacina'' and ''Limacina helicina'' in Svalbard waters and the Arctic Ocean: trophic implications". ''Polar Biology'' 24(3): 163–170. . * Gilmer R. W. & Lalli C. M. (1990). "Bipolar variation in ''Clione'', a gymnosomatous pteropod". ''Am. Malacol. Union Bull.'' 8(1): 67–75. * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp. 180–213 * Gosliner T. (1987). ''Nudibranchs of southern Africa: A guide to Opisthobranch molluscs of southern Africa''. Sea Challengers, Monterey. * Gosner, K.L. 1971. ''Guide to identification of marine and estuarine invertebrates: Cape Hatteras to the Bay of Fundy.'' John Wiley & Sons, Inc. 693 p. * Hermans C. O. & Satterlie R. A. (1992). "Fast-Strike Feeding Behaviour in a Pteropod Mollusk, ''Clione limacina'' Phipps". ''The Biological Bulletin'',

Marine Biological Laboratory The Marine Biological Laboratory (MBL) is an international center for research and education in biological and environmental science. Founded in Woods Hole, Massachusetts, in 1888, the MBL is a private, nonprofit institution that was independent ...

, 182
1
��7. * Linkletter, L.E. 1977. ''A checklist of marine fauna and flora of the Bay of Fundy''. Huntsman Marine Laboratory, St. Andrews, N.B. 68 p. * Morton J. E. (1958). "Observations on the gymnosomatous pteropod ''Clione limacina'' (Phipps)". ''

Journal of the Marine Biological Association of the United Kingdom The ''Journal of the Marine Biological Association of the United Kingdom'' is a peer-reviewed scientific journal that was established in August 1887. Originally set up to provide members of the Marine Biological Association of the United Kingdo ...

'' 37: 287–297. * Muller, Y. (2004). ''Faune et flore du littoral du Nord, du Pas-de-Calais et de la Belgique: inventaire. oastal fauna and flora of the Nord, Pas-de-Calais and Belgium: inventory'. Commission Régionale de Biologie Région Nord Pas-de-Calais: France. 307 pp. * Thomas, M.L.H. (ed.). 1983. ''Marine and coastal systems of the Quoddy Region, New Brunswick''. Canadian Special Publication of Fisheries and Aquatic Sciences 64. 306 p. * Trott, T.J. 2004. ''Cobscook Bay inventory: a historical checklist of marine invertebrates spanning 162 years''. Northeastern Naturalist (Special Issue 2): 261–324. * * Turgeon, D. D., et al. 1998. ''Common and scientific names of aquatic invertebrates of the United States and Canada''. American Fisheries Society Special Publication 26

External links

{{Taxonbar, from=Q2453516 Clionidae Molluscs of the Pacific Ocean Marine molluscs of Asia Gastropods described in 1774 Taxa named by Constantine Phipps, 2nd Baron Mulgrave