Walleye
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Percidae
Genus: Sander
Species:
S. vitreus
Binomial name
Sander vitreus
(Mitchill, 1818)
Synonyms[2]
  • Perca vitrea Mitchill, 1818
  • Stizostedion vitreum (Mitchill, 1818)
  • Lucioperca americana Cuvier, 1828
  • Lucioperca grisea DeKay, 1842
  • Stizostedion glaucum Hubbs, 1926

The walleye (Sander vitreus, synonym Stizostedion vitreum), also called the yellow pike or yellow pickerel,[3] is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relative of the European zander, also known as the pikeperch. The walleye is sometimes called the yellow walleye to distinguish it from the blue walleye, which is a subspecies that was once found in the southern Ontario and Quebec regions, but is now presumed extinct.[4] However, recent genetic analysis of a preserved (frozen) 'blue walleye' sample suggests that the blue and yellow walleye were simply phenotypes within the same species and do not merit separate taxonomic classification.[5]

In parts of its range in English-speaking Canada, the walleye is known as a pickerel, though the fish is not related to the true pickerels, which are a member of the family Esocidae.[6]

Walleyes show a fair amount of variation across watersheds. In general, fish within a watershed are quite similar and are genetically distinct from those of nearby watersheds. The species has been artificially propagated for over a century and has been planted on top of existing populations or introduced into waters naturally devoid of the species, sometimes reducing the overall genetic distinctiveness of populations.

Etymology

Walleye, Sander vitreus
Walleye, Sander vitreus

The name "walleye" comes from its pearlescent eyes caused by the reflective tapetum lucidum which, in addition to allowing the fish to see well in low-light conditions, gives its eyes an opaque appearance. Their vision affects their behavior. They avoid bright light and feed in low light on fish that cannot see as well as they do.[7] Many anglers look for walleyes at night since this is when major feeding efforts occur. The fish's eyes also allow them to see well in turbid waters (stained or rough, breaking waters), which gives them an advantage over their prey. Thus, walleye anglers commonly look for locations where a good "walleye chop" (i.e., rough water) occurs. Their vision also allows the fish to populate the deeper regions in a lake, and they can often be found in deeper water, particularly during the warmest part of the summer and at night.[8]

Description

Walleyes are largely olive and gold in color (hence the French common name: doré—golden). The dorsal side of a walleye is olive, grading into a golden hue on the flanks. The olive/gold pattern is broken up by five darker saddles that extend to the upper sides. The color shades to white on the belly. The mouth of a walleye is large and is armed with many sharp teeth. The first dorsal and anal fins are spinous, as is the operculum. Walleyes are distinguished from their close relative the sauger by the white coloration on the lower lobe of the caudal fin, which is absent on the sauger. In addition, the two dorsals and the caudal fin of the sauger are marked with distinctive rows of black dots which are absent from or indistinct on the same fins of walleyes.[9]

Length and weight

Weight and length of walleyes
Weight and length of walleyes

Walleyes grow to about 80 cm (31 in) in length, and weigh up to about 9 kg (20 lb). The maximum recorded size for the fish is 107 cm (42 in) in length and 13 kilograms (29 lb) in weight. The rate depends partly on where in their range they occur, with southern populations often growing faster and larger. In general, females grow larger than males. Walleyes may live for decades; the maximum recorded age is 29 years. In heavily fished populations, however, few walleye older than five or six years of age are encountered. In North America, where they are highly prized, their typical size when caught is on the order of 30 to 50 cm (12 to 20 in), substantially below their potential size.

As walleye grow longer, they increase in weight. The relationship between total length (L) and total weight (W) for nearly all species of fish can be expressed by an equation of the form

Invariably, b is close to 3.0 for all species, and c is a constant that varies among species. For walleye, b = 3.180 and c = 0.000228 (with units in inches and pounds) or b = 3.180 and c = 0.000005337 (with units in cm and kg).[10]

This relationship suggests a 50 cm (20 in) walleye will weigh about 1.5 kg (3.3 lb), while a 60 cm (24 in) walleye will likely weigh about 2.5 kg (5.5 lb).

Population dynamics

The Garrison Dam National Fish Hatchery at Garrison Dam, North Dakota is the largest walleye hatchery in the world. Although they are in high demand for fishing and consumption in North Dakota, elsewhere they are considered a nuisance. For that reason GDNFH is also researching hormonal population control to provide control options to other areas.[11]

Reproduction

Walleye larva
Walleye larva

In most of the species' range, male walleyes mature sexually between three and four years of age. Females normally mature about a year later. Adults migrate to tributary streams in late winter or early spring to lay eggs over gravel and rock, although open-water reef or shoal-spawning strains are seen, as well. Some populations are known to spawn on sand or vegetation. Spawning occurs at water temperatures of 6 to 10 °C (43 to 50 °F). A large female can lay up to 500,000 eggs, and no care is given by the parents to the eggs or fry. The eggs are slightly adhesive and fall into spaces between rocks. The incubation period for the embryos is temperature-dependent, but generally lasts from 12 to 30 days. After hatching, the free-swimming embryos spend about a week absorbing a relatively small amount of yolk. Once the yolk has been fully absorbed, the young walleyes begin to feed on invertebrates, such as fly larvæ and zooplankton. After 40 to 60 days, juvenile walleyes become piscivorous. Thenceforth, both juvenile and adult walleyes eat fish almost exclusively, frequently yellow perch or ciscoes, moving onto bars and shoals at night to feed. Walleye also feed heavily on crayfish, minnows, and leeches.

Taxonomy

The walleye is part of the North American clade within the genus Sander, alongside the sauger (S. canadensis). Hubbs described a taxon called the blue walleye (S. glaucus) from the Great Lakes but subsequent taxonomic work showed no consistent differences between this form and the "yellow" walleye and the blue walleye is now considered to be a synonym and color variant of the walleye.[12] The walleye was first formally described by the American naturalist Samuel Latham Mitchill (1764-1831) with the type locality given as Cayuga Lake near Ithaca, New York.[13]

As food

Fresh walleye being cooked over a fire
Fresh walleye being cooked over a fire

The walleye is considered to be a quite palatable freshwater fish, and consequently, is fished recreationally and commercially for food.[14] Because of its nocturnal feeding habits, it is most easily caught at night using live minnows or lures that mimic small fish. In Minnesota, the walleye is often fished for in the late afternoon on windy days (known as a "walleye chop") or at night. Most commercial fisheries for walleye are situated in the Canadian waters of the Great Lakes. Often served as a sandwich in Minnesota's pubs where the fish is very popular, deep fried walleye on a stick is a Minnesota State Fair food.[15]

Fishing

Main article: Walleye fishing

Because walleyes are popular with anglers, fishing for walleyes is regulated by most natural resource agencies. Management may include the use of quotas and length limits to ensure that populations are not overexploited. For example, in Michigan, walleyes shorter than 15 in (38 cm) may not be legally kept, except in Lake St. Clair, the St. Clair River, and Saginaw Bay where fish as short as 13 in (33 cm) may be taken.

Since walleyes have excellent visual acuity under low illumination levels, they tend to feed more extensively at dawn and dusk, on cloudy or overcast days, and under choppy conditions when light penetration into the water column is disrupted. Although anglers interpret this as light avoidance, it is merely an expression of the walleyes' competitive advantage over their prey under those conditions. Similarly, in darkly stained or turbid waters, walleyes tend to feed throughout the day. In the spring and fall, walleyes are located near the shallower areas due to the spawning grounds, and they are most often located in shallower areas during higher winds due to the murkier, higher oxygenated water at around six feet deep.[16] On calm spring days, walleyes are more often located at the deep side of the shoreline drop-off and around shore slopes around or deeper than 10 feet.[17]

As a result of their widespread presence in Canada and the northern United States, walleyes are frequently caught while ice fishing, a popular winter pastime throughout those regions.

"Walleye chop" is a term used by walleye anglers for rough water typically with winds of 10 to 25 km/h (6 to 16 mph), and is one of the indicators for good walleye fishing due to the walleyes' increased feeding activity during such conditions. In addition to fishing this chop, night fishing with live bait can be very effective.

The current all-tackle world record for a walleye is held by Mabry Harper, who caught an 11.34-kg (25-lb) walleye in Old Hickory Lake in Tennessee on 2 August 1960.[18]

Cultural aspects

Large walleye statue at Lake Mille Lacs in Garrison, Minnesota
Large walleye statue at Lake Mille Lacs in Garrison, Minnesota

The walleye is the state fish of Minnesota, Vermont, and South Dakota, and the official provincial fish of Manitoba[19] and Saskatchewan.[20]

It is very popular with Minnesota residents; more walleye is eaten in Minnesota than in any other jurisdiction of the United States. Both Garrison and Baudette, Minnesota, claim to be the "Walleye Capital of the World", each with a large statue of the fish.[21]

Winnipeg, Manitoba, considers the walleye (referred to locally as "pickerel") its most important local fish.[22]: 76  Icelandic fishermen in Lake Winnipeg traditionally supplied the Winnipeg market.[22]: 23–26 


See also

References

  1. ^ NatureServe (2013). "Sander vitreus". IUCN Red List of Threatened Species. 2013: e.T202605A18229159. doi:10.2305/IUCN.UK.2013-1.RLTS.T202605A18229159.en. Retrieved 16 September 2020.
  2. ^ Froese, Rainer and Pauly, Daniel, eds. (2019). Sander &speciesname= vitreum" Sander vitreum " in FishBase. December 2019 version.
  3. ^ http://www.ontariofishes.ca/fish_detail.php?FID=151
  4. ^ "Le doré bleu existe!". lapresse.ca. 16 August 2008. Retrieved 24 March 2018.
  5. ^ Haponski, Amanda E.; Stepien, Carol A. (2014). "A population genetic window into the past and future of the walleye Sander vitreus: relation to historic walleye and the extinct "blue pike" S. v. "glaucus"". Giornale della Libreria. 14 (1): 133. doi:10.1186/1471-2148-14-133. PMC 4229939. PMID 24941945. Retrieved 10 July 2015.
  6. ^ Crossman, E.J. "Walleye - The Canadian Encyclopedia". Retrieved 29 April 2017.
  7. ^ "Walleye biology and identification". Minnesota Department of Natural Resources. Retrieved 29 May 2021.
  8. ^ Northern Wisconsin All-Outdoors Atlas & Field Guide. Sportsman's Connection. 2012. p. 5.
  9. ^ "In-Fisherman - The World's Foremost Authority On Freshwater Fishing". In-Fisherman. Retrieved 24 March 2018.
  10. ^ Anderson, R. O.; Neumann, R. M. (1996). "Length, Weight, and Associated Structural Indices". In Murphy, B. E.; Willis, D. W. (eds.). Fisheries Techniques (Second ed.). Bethesda, MD: American Fisheries Society. ISBN 1-888569-00-X.
  11. ^ Wilson, Malik (12 February 2021). "Garrison Dam National Fish Hatchery spearheading walleye population control project". KX NEWS. Retrieved 14 February 2021.
  12. ^ Carol A. Stepien & Amanda Haponski (2015). "Taxonomy, Distribution, and Evolution of the Percidae". In Patrick Kestemont; Konrad Dabrowski & Robert C. Summerfelt (eds.). Biology and Culture of Percid Fishes. Springer, Dordrecht. pp. 3–60. doi:10.1007/978-94-017-7227-3_1. ISBN 978-94-017-7227-3.
  13. ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Perca vitrea". Catalog of Fishes. California Academy of Sciences. Retrieved 16 September 2020.
  14. ^ "Walleye, Sander vitreus". Department of Natural Resources (DNR), State of Michigan. Retrieved 15 March 2013.
  15. ^ Field and Stream July 2005
  16. ^ Joe Fellegy, Jr., Walleyes and Walleye Fishing (Dillon Press, 1974), 57, 58
  17. ^ Fellegy, 60
  18. ^ International Game and Fish Association (1960). "IGFA All-Tackle World Record". IGFA. Retrieved 20 April 2014.
  19. ^ "OFFICIAL EMBLEMS OF MANITOBA|Fish Emblem|Pickerel" (PDF). gov.mb.ca. Retrieved 3 June 2021.
  20. ^ "Saskatchewan". Canadian Heritage. Retrieved 15 March 2013.
  21. ^ "Walleyed War of the Walleye Capitals". RoadsideAmerica.com. Doug Kirby, Ken Smith, Mike Wilkins.
  22. ^ a b Nicholson, Karen (May 2007). "A History of Manitoba's Commercial Fishery 1872-2005" (PDF). Manitoba Historic Resources Branch. Retrieved 8 May 2017.

Further reading