Palaemon adspersus
Encyclopedia
Palaemon adspersus is a species
of shrimp
that is frequent in the Baltic Sea
, and is the subject of fisheries
in Denmark
. It is up to 70 mm (2.8 in) long, and lives in Zostera
beds.
bears distinctive spots of pigment on its lower half.
in the Danish straits
. In the Baltic Sea
, it can tolerate salinities
as low as 5‰, but it overwinters in deeper, more saline waters offshore. In Denmark
, P. adspersus is closely associated with Zostera
(eelgrass) beds, and is replaced by Palaemon elegans where the eelgrass is lacking.
(1758, 1761). As more genera were split from Linnaeus' Cancer, this species became known as Leander squilla, while the genus Palaemon
was used for other species. In 1897, Mary Jane Rathbun
realised that a type species
for the genus Palaemon had been made in 1810 by Pierre André Latreille
, and that the chosen species was Cancer squilla. This required the genus then known as Leander to become Palaemon, while the genus then known as Palaemon had to become Macrobrachium
. Not all biologists followed the new nomenclature, and the confusion was eventually resolved by a ruling from the International Commission on Zoological Nomenclature
(ICZN), which stated that the type species of Palaemon would be Palaemon adspersus.
In 1958, Lipke Holthuis
petitioned the ICZN to suppress the Linnaean name Cancer squilla because it had come to be used for the species Palaemon elegans even though the original description was of a different species. Despite opposition from some carcinologists, including Robert Gurney
, the ICZN concurred, leaving Palaemon adspersus Rathke, 1837 the oldest available name
for the species.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
that is frequent in the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
, and is the subject of fisheries
Shrimp fishery
A shrimp fishery is a fishery directed toward harvesting either shrimp or prawns. .-Commercial shrimping:...
in Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
. It is up to 70 mm (2.8 in) long, and lives in Zostera
Zostera
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...
beds.
Description
Palaemon adspersus is up to 70 millimetres (2.8 in) long, with a plain yellowish-grey body. The rostrumRostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
bears distinctive spots of pigment on its lower half.
Distribution and ecology
Palaemon adspersus is uncommon over most of north-western Europe, but forms the basis of a significant fisheryShrimp fishery
A shrimp fishery is a fishery directed toward harvesting either shrimp or prawns. .-Commercial shrimping:...
in the Danish straits
Danish straits
The Danish straits are the three channels connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. They transect Denmark, and are not to be confused with the Denmark Strait between Greenland and Iceland...
. In the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
, it can tolerate salinities
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
as low as 5‰, but it overwinters in deeper, more saline waters offshore. In Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, P. adspersus is closely associated with Zostera
Zostera
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...
(eelgrass) beds, and is replaced by Palaemon elegans where the eelgrass is lacking.
Taxonomic history
Carl Linnaeus described this species under the name Cancer squilla in his Systema NaturaeSystema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
(1758, 1761). As more genera were split from Linnaeus' Cancer, this species became known as Leander squilla, while the genus Palaemon
Palaemon (genus)
Palaemon is a genus of shrimp of the family Palaemonidae, containing the following species:*Palaemon adspersus Rathke, 1837*Palaemon affinise H. Milne-Edwards, 1837*Palaemon capensis Palaemon is a genus of shrimp of the family Palaemonidae, containing the following species:*Palaemon adspersus...
was used for other species. In 1897, Mary Jane Rathbun
Mary Rathbun
Mary J. Rathbun was an American zoologist who specialized in crustaceans. She worked at the Smithsonian Institution, often unaided, from 1884 until her death...
realised that a type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
for the genus Palaemon had been made in 1810 by Pierre André Latreille
Pierre André Latreille
Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...
, and that the chosen species was Cancer squilla. This required the genus then known as Leander to become Palaemon, while the genus then known as Palaemon had to become Macrobrachium
Macrobrachium
Macrobrachium is a genus of freshwater shrimp characterised by the extreme enlargement of the second pair of pereiopods, at least in the male...
. Not all biologists followed the new nomenclature, and the confusion was eventually resolved by a ruling from the International Commission on Zoological Nomenclature
International Commission on Zoological Nomenclature
The International Commission on Zoological Nomenclature is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 28 members from 20 countries, mainly practicing zoological taxonomists...
(ICZN), which stated that the type species of Palaemon would be Palaemon adspersus.
In 1958, Lipke Holthuis
Lipke Holthuis
Lipke Bijdeley Holthuis was a Dutch carcinologist, considered one of the "undisputed greats" of carcinology, and "the greatest carcinologist of our time"....
petitioned the ICZN to suppress the Linnaean name Cancer squilla because it had come to be used for the species Palaemon elegans even though the original description was of a different species. Despite opposition from some carcinologists, including Robert Gurney
Robert Gurney
Robert Gurney was a British zoologist most famous for his monographs on British Freshwater Copepoda and the Larvae of Decapod Crustacea . He was not affiliated with any institution, but worked at home, initially in Norfolk, and later near Oxford...
, the ICZN concurred, leaving Palaemon adspersus Rathke, 1837 the oldest available name
Principle of Priority
thumb|270px|Boa manditraIn zoology, the scientific study of animals, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, defined by Article 23....
for the species.