''Plagioscion'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

es belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Sciaenidae Sciaenidae is a family (biology), family of ray-finned fishes belonging to the Order (biology), order Acanthuriformes. They are commonly called drums or croakers in reference to the repetitive throbbing or drumming sounds they make. The family co ...

, the drums and croakers. They are found in tropical and subtropical South America where they inhabit fresh and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

waters. Some species (notably ''P. squamosissimus'' and ''P. surinamensis'') are important

food fish Many species of fish are caught by humans and consumed as food in virtually all regions around the world. Their meat has been an important dietary source of protein and other nutrients in the human diet. The English language does not have a s ...

and support major fisheries. Depending on the exact species, they reach up to about in length. In general, the various species are similar and are not easily separated by

meristics Meristics is an area of zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to i ...

or colour. ''Plagioscion'' sometimes occur in

schools A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...

. They are predators and the adults are essentially

piscivorous A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted rept ...

. The largest in the genus, ''P. squamosissimus'', mainly feeds on fish smaller than , but may take ones up to about 60% of the length of the ''Plagioscion'' itself. Although the family Sciaenidae primarily is marine, there are four genera with freshwater species in South America. In addition to ''Plagioscion'', this is '' Pachypops'', '' Pachyurus'' and '' Petilipinnis''.

Taxonomy

''Plagoscion'' was first proposed as a genus in 1861 by the American

biologist A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...

Theodore Gill Theodore Nicholas Gill (March 21, 1837 – September 25, 1914) was an American ichthyologist, mammalogist, malacologist, and librarian. Career Born and educated in New York City under private tutors, Gill early showed interest in natural hist ...

without including any species. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

was later designated as ''Sciaena squamosissima'' by

Jordan Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...

and

Eigenmann Eigenmann () is a surname. Notable persons with that surname include: * Andi Eigenmann (born 1990), Filipino actress * Carl H. Eigenmann (1863–1927), German–American ichthyologist, husband of Rosa Eigenmann * Eduardo de Mesa Eigenmann, birth n ...

, this species had been described in 1840 by

Johann Jakob Heckel Johann Jakob Heckel (23 January 1790 – 1 March 1857) was an Austrian taxidermist, zoology, zoologist, and ichthyology, ichthyologist from Mannheim in the Electoral Palatinate. He worked at the Royal natural history cabinet in Vienna which later ...

with its type locality given as Suriname. This genus has been placed in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Cynoscioninae by some workers, but the 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' does not recognise subfamilies within the Sciaenidae which it places in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Acanthuriformes Acanthuriformes is a large, diverse order of mostly marine ray-finned fishes, part of the Percomorpha clade. In the past, members of this clade were placed in the suborders Acanthuroidea and Percoidea of the order Perciformes, but this treatment ...

Etymology

''Plagioscion'' is a combination of ''plagio'', meaning "oblique", and ''scion'', the modern

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

name of ''

Umbrina cirrosa ''Umbrina cirrosa'', the shi drum, is a species of marine fish from the warmer waters of the eastern Atlantic Ocean, Mediterranean Sea and the Black Sea. It is a commercially important species which is trawled for and farmed in aquaculture, as w ...

'', which Gill preferred over ''sciaena'' because he did not like the sound of ''Cynosciaena''. Gill did not explain what ''palgio'' was alluding to but he did mention that the crest and margin of the

preoperculum This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes. A B C ...

were "oblique, nearly parallel".

Species

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

currently recognizes 7 species in this genus. The validity of ''P. casattii'' and ''P. surinamensis'' are questionable (both possibly

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

s of ''P. squamosissimus''). In contrast, genetic analysis indicates that two currently unrecognized,

cryptic 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 ...

exist. * '' Plagioscion auratus'' Castelnau, 1855 (Black curbinata) * '' Plagioscion casattii'' Aguilera & de Aguilera, 2001 * '' Plagioscion montei'' Soares & Casatti, 2000 * '' Plagioscion pauciradiatus''

Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner descri ...

, 1917 * '' Plagioscion squamosissimus'' Heckel, 1840 (South American silver croaker) * '' Plagioscion surinamensis'' Bleeker, 1873 (Pacora) * '' Plagioscion ternetzi'' Boulenger, 1895 (Freshwater croaker) ''

Catalog of Fishes Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...

'' includes the following species: ''P. casattii'' and ''P. surinamensis'' are treated as

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

s of ''P. squamosissmus''.

References

Sciaenidae {{perciformes-stub