Montana Field Guide

The Zander (Sander lucioperca) is a sportfish introduced to North America sharing a genus and some resemblance to the Walleye (Sander vitreous). The species has a long slender body, with no spines on the gill cover (Larsen and Berg 2011). The mouth has many small teeth and fewer large teeth for catching their prey (Larsen and Berg 2011). The species has two dorsal fins, one with 13 to 20 spines and one with 1-2 spines and 18 to 24 soft rays (Larsen and Berg 2011). The caudal fin has 17 soft rays and the anal fin has 2-3 spines and 10-14 soft rays (Larsen and Berg 2011). Zander lengths reach upwards of 100-130 cm with top weights of about 15-20 kg (Larsen and Berg 2011, Kottelat and Greyhof 2007, Keith and Allardi 2001, Robins et al. 1991). Maximum age is inversely correlated to growth rate, slow-growing Zander in the northern part of the distribution area reach 20-24 years of age, while faster-growing Zander in the southern part only reach about 8-9 years (Sonesten 1991).

One of the most important features to differentiate zander from walleye is the spotted dorsal fin, which has a spiny appearance. But, our native sauger also has a spotted dorsal fin, so the distinguishing factor between sauger and zander is that zander has blotchy spots on the sides of the body, while the sauger has an overall darker hue with dark saddles (large patches).

May undertake short spawning migrations (Freyhof and Kottelat 2008). Individuals foraging in brackish water migrate to freshwater habitats (migrations of up to 250 km have been recorded), homing well developed, even nearby populations may be relatively isolated (Freyhof and Kottelat 2008).

Inhabits large, turbid rivers and eutrophic lakes, brackish coastal lakes and estuaries. Needs sand or gravels for spawning.

Feeds mainly on gregarious, pelagic fishes, piscivorous. Zander feed heavily on prey of small size and there is concern among European fish resource managers that introduced Zander may cause a collapse in resident prey fish stocks (Hickley 1986).

Inhabits large, turbid rivers and eutrophic lakes, brackish coastal lakes and estuaries. Concern exists that Zander and walleye could hybridize. So far there has been no evidence of that happening (Fuller and Nielson 2018). There has been no discernible impact on native walleye or perch populations (Fuller and Nielson 2018 They are a potamodromous freshwater fish and prefers depths from 2-30m (Riede 2004; Billard 1997; Gerstmeier and Romig 1998).

Lives up to 17 years. Spawns for the first time at 3-10 years, usually at four (Freyhof and Kottelat 2008). Spawns in April-May, could be from late February until July, depending on latitude and altitude, when temperatures reach 10-14°C in spawning grounds (lowest temperature for egg incubation 11.5°C) (Freyhof and Kottelat 2008). Males are territorial and excavate shallow depressions about 50 cm in diameter and 5-10 cm deep in sand or gravel, or among exposed plant roots on which eggs are deposited, usually in turbid water and at 1-3 m depth (Freyhof and Kottelat 2008). Spawns in pairs, at dawn or night and female remains over the nest while male circles rapidly around, at about 1 meter from nest. Then male takes a vertical orientation and both swim around swiftly, and eggs and sperm are release. After all the eggs are released the female leaves the nest site, the male defends the nest and fans the eggs with his pectorals (Freyhof and Kottelat 2008). Females spawn once a year (Freyhof and Kottelat 2008). Feeding larval zander are positively phototactic and feed on pelagic organisms after they leave the nest for open water (Freyhof and Kottelat 2008).

There seems to be no limiting factors in the establishment of this species into Montana's waterbodies. It can withstand cold water temperatures that are found in Northern Europe and Siberia and would likely survive conditions during a Montana winter.