Editing Northern pike (section)

==Description==
[[File:Esox lucius 30zz.jpg|thumb|Skull of a Northern pike]]
Northern pike are most often olive green, shading from yellow to white along the belly. The [[wikt:flank|flank]] is marked with short, light bar-like spots and a few to many dark spots on the fins. Sometimes, the fins are reddish. Younger pike have yellow stripes along a green body; later, the stripes divide into light spots and the body turns from green to olive green. The lower half of the [[Operculum (fish)|gill cover]] lacks scales, and it has large sensory [[Canal pore|pores]] on its [[head]] and on the underside of its lower [[jaw]] which are part of the [[lateral line]] system. Unlike the similar-looking and closely related [[muskellunge]], the northern pike has light markings on a dark body background and fewer than six sensory pores on the underside of each side of the lower jaw.

A hybrid between northern pike and muskellunge is known as a [[tiger muskellunge]] (''Esox masquinongy × lucius'' or ''Esox lucius × masquinongy'',<ref>{{cite web|url=http://www.gen.umn.edu/research/fish/fishes/tiger_muskie.html|title=Tiger muskie|url-status=dead|archive-url=https://web.archive.org/web/20080807195946/http://www.gen.umn.edu/research/fish/fishes/tiger_muskie.html|archive-date=7 August 2008|website= University of Minnesota|access-date=6 October 2020}}</ref> depending on the sex of each of the contributing species). In the hybrids, the males are invariably sterile, while females are often fertile, and may back-cross with the parent species.<ref>{{cite web|url=https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=677 |title=Tiger muskellunge (''Esox lucius'' x E. masquinongy) – FactSheet |publisher=Nas.er.usgs.gov |access-date=2 March 2011}}</ref> Another form of northern pike, the silver pike, is not a subspecies but rather a [[mutation]] that occurs in scattered populations. Silver pike, sometimes called silver muskellunge, lack the rows of spots and appear silver, white, or silvery-blue in color.<ref>Craig, John F. ed. ''Pike: Biology and Exploitation''. Chapman & Hall, London. 1996 pp. 1</ref> When ill, silver pike have been known to display a somewhat purplish hue; long illness is also the most common cause of male sterility.

In [[Italy]], the newly identified species ''[[Esox cisalpinus]]'' ("southern pike") was long thought to be a color variation of the northern pike, but was in 2011 announced to be a species of its own.<ref>{{cite journal|title=Molecular and Phenotypic Evidence of a New Species of Genus Esox (Esocidae, Esociformes, Actinopterygii): The Southern Pike, ''Esox flaviae'' |journal=PLOS ONE |volume=6 |issue=12 |pages=e25218 |doi=10.1371/journal.pone.0025218 |pmid=22164201 |pmc=3229480 |year = 2011|last1 = Lucentini|first1 = Livia|last2=Puletti |first2=Maria Elena |last3=Ricciolini |first3=Claudia |last4=Gigliarelli |first4=Lilia |last5=Fontaneto |first5=Diego |last6=Lanfaloni |first6=Luisa |last7=Bilò |first7=Fabiana |last8=Natali |first8=Mauro |last9=Panara |first9=Fausto |bibcode=2011PLoSO...625218L |doi-access=free }}</ref>

===Length and weight===
Northern pike in [[North America]] seldom reach the size of their European counterparts; one of the largest specimens known was a {{convert|21|kg|lb|abbr=on}} specimen from New York. It was caught in [[Great Sacandaga Lake]] on 15 September 1940 by Peter Dubuc. Reports of far larger pike have been made, but these are either misidentifications of the pike's larger relative, the [[muskellunge]], or simply have not been properly documented and belong in the realm of legend.

[[File:northern pike weight length graph.jpg|thumb]]
As northern pike grow longer, they increase in weight, and the relationship between length and weight is not linear. The relationship between total length (''L'', in inches) and total weight (''W'', in pounds) for nearly all species of fish can be expressed by an [[Standard weight in fish|equation]] of the form
:<math>W = c L^b.</math>

Invariably, ''b'' is close to 3.0 for all species, and ''c'' is a constant that varies among species. For northern pike, ''b'' = 3.096 and ''c'' = 0.000180 (''c'' = 7.089 enables one to put length in meters and weight in kilograms).<ref>Anderson, R. O. and Neumann, R. M. (1996) "Length, Weight, and Associated Structural Indices", in ''Fisheries Techniques'', 2nd edition, B. E. Murphy and D. W. Willis, eds., American Fisheries Society. {{ISBN|978-1-934874-29-5}}</ref> The relationship described in this section suggests a {{convert|20|in|cm|round=5|adj=on|order=flip}} northern pike will weigh about {{convert|2|lb|1|abbr=on|order=flip}}, while a {{convert|26|in|cm|round=5|adj=on|order=flip}} northern pike will weigh about {{convert|4|lb|abbr=on|order=flip}}.

===Age===
Northern Pike typically live to 10–15 years, but sometimes up to 25 years.<ref>[https://canalrivertrust.org.uk/enjoy-the-waterways/fishing/fish-species/pike Pike Fish]. Canal & River Trust, UK</ref>