Paramysis bakuensis is a species of mysid crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

 from the genus Paramysis

Paramysis

Paramysis is a genus of mysid crustaceans in family Mysidae, distributed in coastal zone of low boreal East Atlantic Ocean, Mediterranean Sea and the basins of Black Sea, Sea of Azov and Caspian Sea .-Biogeography:The majority of Paramysis species are brackish- or...

, named by the locality from where it was originally described, the town of Baku

Baku

Baku , sometimes spelled as Baki or Bakou, is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. It is located on the southern shore of the Absheron Peninsula, which projects into the Caspian Sea. The city consists of two principal...

 in Azerbaijan

Azerbaijan

Azerbaijan , officially the Republic of Azerbaijan is the largest country in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west, and Iran to...

 by the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

.

Taxonomic history

After the description by Norwegian carcinologist Georg Ossian Sars, the species was mentioned only twice among the mysids of the Sea of Azov

Sea of Azov

The Sea of Azov , known in Classical Antiquity as Lake Maeotis, is a sea on the south of Eastern Europe. It is linked by the narrow Strait of Kerch to the Black Sea to the south and is bounded on the north by Ukraine mainland, on the east by Russia, and on the west by the Ukraine's Crimean...

 basin, but soon synonimized with Paramysis baeri

Paramysis baeri

Paramysis baeri is a species of mysid crustacean from the genus Paramysis, named in honour of the prominent biologist Karl Ernst von Baer. Its body is long, and it is only found in the coastal waters of the Caspian Sea, on sandy and muddy bottoms, at depths of less than...

. In 60 years it was rediscovered while combined morphological and molecular revision of P. baeri, restored and redescribed.

Distribution

The species is distributed throughout brackish and fresh waters of the Ponto-Caspian basin

Paratethys

The Paratethys ocean, Paratethys sea or just Paratethys was a large shallow sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in western Asia. The sea was formed during the Oxfordian epoch as an extension of the rift that formed the Central Atlantic Ocean and...

. It is found in the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

, the Sea of Azov

Sea of Azov

The Sea of Azov , known in Classical Antiquity as Lake Maeotis, is a sea on the south of Eastern Europe. It is linked by the narrow Strait of Kerch to the Black Sea to the south and is bounded on the north by Ukraine mainland, on the east by Russia, and on the west by the Ukraine's Crimean...

, rivers Volga, Don

Don River (Russia)

The Don River is one of the major rivers of Russia. It rises in the town of Novomoskovsk 60 kilometres southeast from Tula, southeast of Moscow, and flows for a distance of about 1,950 kilometres to the Sea of Azov....

, Kuban

Kuban

Kuban is a geographic region of Southern Russia surrounding the Kuban River, on the Black Sea between the Don Steppe, Volga Delta and the Caucasus...

 and Danube

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

; in the rivers up to over 500 km upstream. All the previous mentionings of P. baeri outside the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

 should probably be attributed to P. bakuensis. The ranges of P. bakuensis and P. baeri partly overlap: they can be found together in the Caspian Sea

Caspian Sea

The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

.

Habitat

Paramysis bakuensis is a coastal sublittoral species in the sea, found at the depth below 10 m (32.8 ft), preferably on sandy or sandy-muddy bottom. In the rivers of the Ponto-Caspian basin

Paratethys

The Paratethys ocean, Paratethys sea or just Paratethys was a large shallow sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in western Asia. The sea was formed during the Oxfordian epoch as an extension of the rift that formed the Central Atlantic Ocean and...

 it lives usually in the riverbed with constant stream and high oxygenation.

Characters

Body length 13–31 mm (0.511811023622047–1.2 ). Can be distinguished from P. baeri by wide, but not wider than long exopod of maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

 2, smooth paradactylar claw-setae of pereiopods 6 and other characters.