''Sander'' (formerly known as ''Stizostedion'') is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of predatory

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Percidae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains more ...

, which also includes the

perch Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Per ...

es,

ruffe The Eurasian ruffe (''Gymnocephalus cernua''), also known as ruffe or pope, is a freshwater fish found in temperate regions of Europe and northern Asia. It has been introduced into the Great Lakes of North America, reportedly with unfortuna ...

s, and darters. They are also known as "pike-perch" because of their resemblance to fish in the unrelated

Esocidae Esocidae is a family of fish in the order Esociformes, which contains pike, pickerel, and mudminnows. While the family traditionally only contained the genus ''Esox'', recent genetic and paleontological research have recovered ''Novumbra'' and ' ...

(pike) family. They are the only genus in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...

Luciopercini, which is one of two tribes in the subfamily Luciopercinae,

Characteristics

''Sander'' species have elongated and laterally compressed bodies and they range in

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

from in the Volga pikeperch (''S. volgensis'') to in the zander (''S. lucioperca''). The species within the genus share canine-like teeth that are at their largest in the zander, and although they are not present in adult Volga pikeperches, they do possess them as juveniles. in addition, they have thin rows of teeth on their jaws, vomer, and palatines, the preopercle shows strong serrations along its edges, a continuous lateral line reaches all the way from the head to the

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

, and this is flanked by additional lateral lines, one each on the upper and lower lobes of the deeply forked

. Further features in common include the absence of genital papillae, seven or eight branchiostegal rays, 12–13 soft rays in the anal fin, and the eye has a reflective layer behind the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

, known as a

tapetum lucidum The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light a ...

, which is an adaptation for seeing in low-light conditions. The species in the genus ''Sander'' are largely

piscivorous A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

as adults.

Species

The genus includes these species: * '' Sander canadensis'' Griffith &

Smith Smith may refer to: People * Metalsmith, or simply smith, a craftsman fashioning tools or works of art out of various metals * Smith (given name) * Smith (surname), a family name originating in England, Scotland and Ireland ** List of people wi ...

, 1834 (sauger) * '' Sander lucioperca''

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

, 1758 (zander) * '' Sander marinus'' G. Cuvier, 1828 (estuarine perch) * ''

Sander vitreus The walleye (''Sander vitreus'', synonym ''Stizostedion vitreum''), also called the yellow pike or yellow pickerel, is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relati ...

'' Mitchill, 1818 (walleye) * '' Sander volgensis'' J. F. Gmelin, 1789 (Volga pikeperch)

Phylogeny

Phylogenetic relationships of the species of genus ''Sander'' based on the concatenated data set of six gene regions and a Bayesian analysis. '' Romanichthys valsanicola'' is the nearest living relative of the genus ''Sander'' and is used as an outgroup to root the tree. This is not universally accepted, though, and the asprete (''Romanichthys valsanicola'') has been more recently placed within the genus '' Zingel''. Two clades are within the genus, a Eurasian one and a North American one, which separated from a common ancestor around 20.8 million years ago (Mya) in the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, when the North Atlantic Land Bridge connecting Europe to eastern North America subsided. The Eurasian clade then speciated from 13.8 Mya, while the two North American species speciated around 5.4 Mya.

References

External links

FishBase list of ''Sander'' species

UN: True Name for Pike Perch
{{DEFAULTSORT:Sander (Genus) Luciopercinae Freshwater fish genera Freshwater fish of Europe