''Littorina saxatilis'', common name the rough periwinkle, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small sea snail, a marine gastropod mollusc in the family

Littorinidae The Littorinidae are a Taxonomy (biology), taxonomic family (biology), family of over 200 species of sea snails, marine (ocean), marine gastropod molluscs in the clade Littorinimorpha, commonly known as periwinkles and found worldwide. Names In ...

, the winkles or periwinkles. First identified in the 1700s, it has been misidentified as a new species 112 times.

Distribution

This species is native to the shores 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 ...

, including Hudson Bay, Baffin Island,

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...

, and the

Barents Sea The Barents Sea ( , also ; no, Barentshavet, ; russian: Баренцево море, Barentsevo More) is a marginal sea of the Arctic Ocean, located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territo ...

, south along the American East Coast to

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...

, and along the European coast to the Straits of Gibraltar. This species has also been introduced to San Francisco Bay, on the

West Coast of the United States The West Coast of the United States, also known as the Pacific Coast, Pacific states, and the western seaboard, is the coastline along which the Western United States meets the North Pacific Ocean. The term typically refers to the contiguous U.S ...

, where it was first observed in 1992.

Shell description

The shell in life often appears green with algae, but the shell itself can be white, red, or brown, sometimes with checkered lines. The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

has 4–5

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

. Maximum recorded shell length is 19 mm.''Littorina saxatilis'' (Olivi)
Malacolog 4.1.1. A Database of Western Atlantic Marine Mollusca.Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". '' PLoS ONE'' 5(1): e8776. . File:Littorina saxatilis shell.png, Apertural view File:Littorina saxatilis 003.jpg, Abapertural view File:Littorina saxatilis001.jpg, A series of shells of Littorina saxatilis

Ecology

Habitat

This species frequently lives in

salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is domin ...

es. it can also be found in crevices of intertidal bedrock, in empty barnacle shells, and under rocks. Like many other periwinkles, this species can survive long exposures out of the water. The species has been recorded alive from depth range 0 – 46 m or up to 183 m (for shells only). In the exposed Galician coast in the Northern Spain, two well differentiated

ecotype In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a specie ...

s are adapted to different shore levels and habitats. The RB ecotype (Ridged and Banded) lives on barnacles in the upper shore. This ecotype displays a larger and more robust shell to resist the attack from predators such as crabs, and a smaller shell aperture in order to reduce the desiccation due to high sunshine exposure. The SU ecotype (Smooth and Unbanded) is found at the lower shore living on mussels. This ecotype shows a smaller and thinner shell with a wider shell aperture to allocate a relatively larger muscular foot providing a higher ability to avoid the dislodgment caused by the heavy wave action. Both ecotypes coexist in an intermediate habitat at the middle shore.

Genetics

''Littorina saxatilis'' has been shown to be an excellent model system for speciation genetics. In the seminal 2001 paper, Wilding ''et al'' demonstrated, using

amplified fragment length polymorphism AFLP-PCR or just AFLP is a PCR-based tool used in genetics research, DNA fingerprinting, and in the practice of genetic engineering. Developed in the early 1990s by KeyGene, AFLP uses restriction enzymes to digest genomic DNA, followed by liga ...

, that the low shore M form of the species were divergent from the high shore H form at number of loci despite gene flow between the forms.

Feeding habits

This snail is a herbivore which grazes on the surface of rocks and mud flats.

Life cycle

The marine snail ''Littorina saxatilis'' has separate sexes,

internal fertilization Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For inte ...

, and a brood pouch with non-planktonic shelled embryos.

Synonyms

* ''Litorina groenlandica'' Menke, 1830 * ''Litorina incarnata'' Philippi, 1846 * ''Litorina marmorata'' L. Pfeiffer, 1839 * ''Litorina sulcata'' Menke, 1830 * ''Littorina castanea'' Deshayes in Deshayes & Milne Edwards, 1843 * ''Littorina danieli'' Locard, 1886 * ''Littorina groenlandica'' (Menke, 1830) * ''Littorina neglecta'' Bean, 1844 * ''Littorina nervillei'' Dautzenberg, 1893 * ''Littorina nervillei'' var. ''major'' Pallary in Seurat, 1924 * ''Littorina nigrolineata'' Gray, 1839 * ''Littorina palliata'' var. ''turritella'' Schlesch, 1916 * ''Littorina rudis'' (Maton, 1797) (synonym) * ''Littorina rudis'' f. ''elatior'' Middendorff, 1849 * ''Littorina rudis'' var. ''albida'' Dautzenberg, 1887 * ''Littorina rudis'' var. ''alticola'' Dacie, 1917 * ''Littorina rudis'' var. ''aurantia'' Dautzenberg, 1887 * ''Littorina rudis'' var. ''brevis'' Dautzenberg, 1887 *'' Littorina rudis'' var. ''conoidea'' Schlesch, 1916 * ''Littorina rudis'' var. ''fasciata'' Dautzenberg, 1887 * ''Littorina rudis'' var. ''finmarchia'' Herzenstein, 1885 * ''Littorina rudis'' var. ''globosa'' Jeffreys, 1865 * ''Littorina rudis'' var. ''globosa'' Martel, 1901 * ''Littorina rudis'' var. ''laevis'' Jeffreys, 1865 * ''Littorina rudis'' var. ''major'' Dautzenberg & P. Fisher, 1912 * ''Littorina rudis'' var. ''rubescens'' Monterosato, 1878 * ''Littorina rudis'' var. ''scotia'' S.M. Smith, 1979 * ''Littorina rudis'' var. ''similis'' Jeffreys, 1865 * ''Littorina rudis'' var. ''sulcata'' Martel, 1901 * ''Littorina rudis'' var. ''tenebrosapallida'' L.E. Adams, 1896 * ''Littorina rudis'' var. ''tessellata'' Dautzenberg, 1893 * ''Littorina saxatile'' La Roque, 1953 * ''Littorina saxatile saxatile'' La Roque, 1953 * ''Littorina saxatilis'' Johnston, 1842 * ''Littorina saxatilis'' f. ''abbreviata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' f. ''conoidea'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' f. ''elongata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' f. ''minor'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis groenlandica'' (Menke, 1830) * ''Littorina saxatilis groenlandica'' var. ''sculpta'' Schlesch, 1931 * ''Littorina saxatilis jugosa'' Montagu, 1803 * ''Littorina saxatilis jugosa'' var. ''bynei'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis jugosa'' var. ''tenuis'' James, 1968 * ''Littorina saxatilis nigrolineata'' Gray, 1839 * ''Littorina saxatilis rudis'' (Maton, 1797) * ''Littorina saxatilis rudis'' var. ''rudissimoides'' James, 1968 * ''Littorina saxatilis scotia'' Graham, 1988 * ''Littorina saxatilis tenebrosa'' ( Montagu, 1803) * ''Littorina saxatilis tenebrosa'' var. ''biinterrupta'' Fischer-Piette & Gaillard, 1963 * ''Littorina saxatilis tenebrosa'' var. ''bizonaria'' James, 1963 * ''Littorina saxatilis tenebrosa'' var. ''elata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis tenebrosa'' var. ''maculata'' Fischer-Piette & Gaillard, 1963 * ''Littorina saxatilis'' var. ''clarilineata'' Fischer-Piette & Gaillard, 1971 * ''Littorina saxatilis'' var. ''flammulata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' var. ''fulva'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' var. ''fusca'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' var. ''gascae'' Fischer-Piette & Gaillard, 1971 * ''Littorina saxatilis'' var. ''groenlandica'' (Menke, 1830) * ''Littorina saxatilis'' var. ''hieroglyphica'' Fischer-Piette, Gaillard & Jouin, 1961 * ''Littorina saxatilis'' var. ''interrupta'' Fischer-Piette, Gaillard & Jouin, 1961 * ''Littorina saxatilis'' var. ''lagunae'' Barnes, 1993 * ''Littorina saxatilis'' var. ''lineata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' var. ''lugubris'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis'' var. ''nigra'' Fischer-Piette & Gaillard, 1971 * ''Littorina saxatilis'' var. ''nojensis'' Fischer-Piette & Gaillard, 1964 * ''Littorina saxatilis'' var. ''rubra'' Fischer-Piette & Gaillard, 1971 * ''Littorina saxatilis'' var. ''rubrolineata'' Fischer-Piette, Gaillard & Delmas, 1967 * ''Littorina saxatilis'' var. ''salvati'' Fischer-Piette, Gaillard & Delmas, 1967 * ''Littorina saxatilis'' var. ''sanguinea'' Coen, 1933 * ''Littorina saxatilis'' var. ''sellensis'' Fischer-Piette & Gaillard, 1964 * ''Littorina saxatilis'' var. ''tractibus'' Fischer-Piette, Gaillard & Jouin, 1961 * ''Littorina saxatilis'' var. ''trifasciata'' Dautzenberg & P. Fisher, 1912 * ''Littorina saxatilis zonata'' Daniel, 1883 * ''Littorina saxoides'' Nardo, 1847 * ''Littorina simplex'' Reeve, 1857 * ''Littorina tenebrosa'' ( Montagu, 1803) * ''Littorina tenebrosa'' f. ''elatior'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''costulata'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''densecostulata'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''grisolacteus'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''intermedia'' Forbes & Hanley, 1850 * ''Littorina tenebrosa'' var. ''rubidus'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''tessellatus'' Middendorff, 1849 * ''Littorina tenebrosa'' var. ''zonatus'' Middendorff, 1849 * ''Littorina zonaria'' Bean, 1844 * ''Nerita rustica'' Nardo, 1847 * ''Turbo obligatus'' Say, 1822 * ''Turbo rudis'' Maton, 1797 * ''Turbo rudissimus'' Johnston, 1842

References

This article incorporates CC-BY-2.0 text from the reference Martínez-Fernández M., Bernatchez L., Rolán-Alvarez E. & Quesada H. (2010). "Insights into the role of differential gene expression on the ecological adaptation of the snail ''Littorina saxatilis''". ''

BMC Evolutionary Biology ''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology ...

'' 10: 356. .Wilding C. S., Butlin R. K. & Grahame J. (2001). "Differential gene expression between parapatric morphs of ''Littorina saxatilis'' detected using RFLP markers". ''

Journal of Evolutionary Biology The ''Journal of Evolutionary Biology'' is a peer-reviewed scientific journal published monthly covering the field of evolutionary biology. It is owned by the European Society for Evolutionary Biology. The founding editor-in-chief was Stephen ...

'' 14: 4. .

External links

In the British Isles

{{DEFAULTSORT:Littorina Saxatilis Littorinidae Gastropods described in 1792 Taxa named by Giuseppe Olivi