''Mysis salemaai'' is a shrimp-like

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

in the Mysida order, inhabiting lakes of

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

and South

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

and brackish waters of the northern

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and ...

Appearance

''Mysis salemaai'' is a transparent shrimp-like crustacean, of less than length. It has two pairs of relatively long antennae, associated with rounded antennal plates; large, stalked

compound eye A compound eye is a visual organ found in arthropods such as insects and crustaceans. It may consist of thousands of ommatidia, which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which disti ...

s; the

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

covered by a coat-like carapace; a muscular, cylindrical

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

; and a tail fan featuring a

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

with a V-shaped terminal cleft. Reproducing females bear a prominent brood pouch (marsupium) between their legs. ''Mysis'' are often called opossum shrimp.

Distribution

''Mysis salemaai'' is a North European species which lives both in fresh and brackish waters. It is found in ten lakes on the island of

, including Lough Neagh, Lough Erne, Lough Corrib and

Lough Ree Lough Ree () is a lake in the midlands of Ireland, the second of the three major lakes on the River Shannon. Lough Ree is the second largest lake on the Shannon after Lough Derg. The other two major lakes are Lough Allen to the north, and Lou ...

. It is also found in several lakes of Southern Scandinavia, including Fureso in Denmark and the large lakes

Vänern Vänern ( , also , ) is the largest lake in Sweden, the largest lake in the European Union and the third-largest lake of all Europe after Ladoga and Onega in Russia. It is located in the provinces of Västergötland, Dalsland, and Värmland i ...

and

Vättern Vättern ( , ) is the second largest lake by surface area in Sweden, after Vänern, and the sixth largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden, to the southeast of Vänern, pointing at the tip ...

in Sweden, and also in the Republic of Karelia. ''Mysis salemaai'' is also common in the

, where it lives in offshore waters of the diluted northern parts of the basin. Previously ''M. salemaai'' was confused with ''

Mysis relicta ''Mysis relicta'' is a shrimp-like crustacean in the Mysida order, native to lakes of Northern Europe and to the brackish Baltic Sea. Appearance Mysis is a small, transparent shrimp-like crustacean, of less than 2.5 cm length. It has ...

'', which is a morphologically similar

sibling species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

. The distributions of the two species overlap in the Baltic Sea and some lakes of Sweden, but ''M. relicta'' is not found in Ireland.

Habitat

''M. salemaai'' is a

benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

species, which in the nighttime performs vertical migration towards the surface.

References

{{Taxonbar, from=Q3932950 Mysida Freshwater crustaceans of Europe Crustaceans described in 2005