The zander, scientifically named Sander lucioperca, belongs to the family Percidae, which encompasses other well-known fish species such as perch, ruffe, and darter. It was first described by Carolus Linnaeus in 1758 and is considered the type species of the genus Sander. Within the genus, the zander forms part of the European clade, which diverged from the North American clade approximately 20.8 million years ago. Notably, the zander shares intriguing reproductive characteristics with the estuarine perch (S. marinus), while also exhibiting similarities with the North American clade in terms of spawning behavior.
The zander stands as the largest member of the Percidae family, featuring a long and muscular body reminiscent of the Northern pike (Esox lucius). Its upper body displays a striking green-brown coloration, extending onto the sides with dark vertical bars, resembling the pattern seen in the European perch (Perca fluviatilis). In contrast, the lower part of the body boasts a creamy-white hue. The fins, including the caudal, pectoral, pelvic, and anal fins, exhibit a paler off-white coloration. Remarkably, the dorsal and caudal fins are adorned with rows of black spots, with the first dorsal fin showcasing the most prominent and sizable spots. Throughout its lifecycle, the zander transitions from a silvery coloration as a juvenile to a darker shade as it matures. Notable physical features include powerful jaws armed with sharp teeth, including two long canines per jaw, and large bulbous eyes, which facilitate vision in low-light conditions.
The zander's size can vary, with the maximum recorded standard length reaching 100 centimeters (39 inches). However, a typical zander is usually found around 50 centimeters (20 inches) in length. In terms of weight, this species can reach an impressive 20 kilograms (44 pounds). It's worth noting that catches of such substantial weight are less common, with average captures being considerably smaller. The current IGFA All-Tackle world record zander, weighing 11.48 kilograms (25.3 pounds), was caught in Lago Maggiore, Switzerland in June 2016. Zander generally attain an average length of 40 to 80 centimeters (15.5 to 31.5 inches), with exceptional individuals reaching up to 120 centimeters (47 inches) in length.
Habitat
Zander primarily inhabit freshwater bodies, particularly large rivers and eutrophic lakes. They exhibit a notable tolerance for brackish water and often make use of coastal lakes and estuaries. In brackish water environments, zander display migratory behavior, venturing upriver for spawning purposes, sometimes covering distances of up to 250 kilometers (160 miles).
Diet
Being carnivorous predators, adult zander feed on smaller schooling fish. Studies conducted around the Baltic Sea have revealed their preference for prey such as European smelt (Osmerus eperlanus), ruffe (Gymnocephalus cernua), European perch, vendace (Coregonus albula), and common roach (Rutilus rutilus). Additionally, cannibalism has been observed among smaller zanders. On occasion, they have been documented feeding on smolts of sea trout (Salmo trutta morph. trutta) and Atlantic salmon (Salmo salar). In certain regions, zander populations thrive in canals with turbid waters resulting from boat traffic. Although their preferred prey in these habitats is the common roach, their presence has a significant impact on gudgeon (Gobio gobio) populations.
Reproduction and Life History
Zander engage in spawning rituals over gravel in flowing water. Males establish territories where they create shallow depressions in sand or gravel, measuring approximately 50 centimeters (20 inches) in diameter and 5 to 10 centimeters (2.0 to 3.9 inches) in depth. These nests can also be found among exposed plant roots, where the female deposits her eggs. Spawning occurs in pairs, primarily during the nighttime and at daybreak. The male circles around the stationary female, maintaining a distance of around 1 meter (3.3 feet) from the nesting depression. After the release of eggs and sperm, the female departs while the male guards the nest, using its pectoral fins to fan and protect the eggs. Each female typically lays all her eggs in one instance, with spawning occurring once a year. Once the larvae hatch, they are attracted to light and subsequently feed on zooplankton and small pelagic organisms. Zander have a maximum lifespan of 17 years, reaching sexual maturity at around 3 to 10 years, with 4 years being the average age for maturity.
The zander is susceptible to various parasites that affect its skin, eyes, and internal organs. One notable parasite found in its gastrointestinal tract is the nematode Anisakis, which can be transmitted to humans if the fish is consumed undercooked or smoked at temperatures below 50 °C (122 °F). Additionally, zander can serve as vectors for the trematode Bucephalus polymorphus, which has been responsible for the decline in populations of native cyprinids in some French river systems during the 1960s and 1970s. Predators of the zander include conspecifics (other zanders), European eels (Anguilla anguilla), Northern pike, European perch, the wels catfish (Silurus glanis), and the Caspian seal (Phoca caspia).