zander

The zander (Sander lucioperca), sander or pikeperch, is a species of ray-finned fish from the family Percidae, which also includes perch, ruffe and darter. It is found in freshwater and brackish habitats in western Eurasia. It is a popular game fish and has been introduced to a variety of localities outside its native range. It is the type species of the genus Sander. Taxonomy The zander was first formally described in 1758 as Perca lucioperca by Carolus Linnaeus in volume 1 of the tenth edition of Systema Naturae and he gave the type locality as "European lakes". When Lorenz Oken (1779-1851) created the genus Sander he made Perca lucioperca its type species. The zander is part of the European clade within the genus Sander which split from a common ancestor with the North American clade, which the walleye (S. vitreus) and the sauger (S. canadensis) belong to, around 20.8 million years ago. Within the European clade the Volga pikeperch (S. volgaensis) is the most basal taxon and shares features with the North American clade, such as being a broadcast spawner. In contrast in the zander and the estuarine perch (S. marinus) the males build nests and the female spawn into these nests and the males then guard the eggs and fry. The lineage leading to the zander is thought to have diverged from the common ancestor with the Volga pikeperch circa 13.8 million years ago while the split from the estuarine perch took place around 9.1 million years ago. Description The zander is the largest member of the Percidae and it usually has a long and muscular body which bears some resemblance to a Northern pike (Esox lucius), hence the alternative English common name of pikeperch. The upper part of its body is green-brown in colour and this extends onto the sides as dark vertical bars, in a pattern not dissimilar to that of the European perch (Perca fluviatilis) while the lower part of the body is creamy-white. Their caudal fin is dark and the pectoral, pelvic and anal fins are paler off-white in colour. The dorsal and caudal fins are marked with rows of black spots on the membranes between the spines and rays, these are largest and most obvious on the first dorsal fin. The juveniles are silvery in colour, becoming darker as they age. They have powerful jaws which are armed with many sharp teeth with two long canines in the front of each jaw. They have large bulbous eyes which are opaque when the fish is living in particularly turbid conditions, an adaptation to low light.