earth science

Northern pike

Northern pike is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Northern pike rather than just read about it. In short: The northern pike (Esox lucius), also known as jack, northern or simply pike, is a species of carnivorous fish of the genus Esox (pikes). It is commonly found in fresh waters of the Northern Hemisphere (i.e. it has a holarctic distribution).

Key takeaways

Northern pike belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Northern pike to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Northern pike from memory before moving on to harder problems.

Reference excerpt

The northern pike (Esox lucius), also known as jack, northern or simply pike, is a species of carnivorous fish of the genus Esox (pikes). It is commonly found in fresh waters of the Northern Hemisphere (i.e. it has a holarctic distribution). Pike can grow to a relatively large size. Their average length is about 40–55 cm (16–22 in), with maximum recorded lengths of up to 150 cm (59 in) and maximum weights of 28.4 kg (63 lb). The IGFA currently recognises a 25 kg (55 lb) pike caught by Lothar Louis on Greffern Lake, Germany, on 16 October 1986, as the all-tackle world-record holding northern pike. Northern pike grow to larger sizes in Eurasia than in North America, and in coastal Eurasian regions than inland ones.

Etymology The northern pike gets its common name from its resemblance to the pole-weapon known as the pike (from the Middle English for 'pointed'). Names such as pike, pickerel, Lakes pike, great northern pike, jackfish, jack, slough shark snake, slimer, slough snake, gator, and hammer handle are used around the globe. Other names incorporating things such as "pointy nose" and "long head" are common as well. The name "Northern" is very popular in the Midwest (in the U.S. Upper Midwest and in the Canadian provinces of Alberta and Manitoba. Numerous other names are or have been in use. Its earlier common name, the luci (now lucy) or luce when fully grown, was used to form its taxonomic name (Esox lucius) and is used in heraldry.

Description

Northern pike are most often olive green, shading from yellow to white along the belly. The 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 gill cover lacks scales, and it has large sensory 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, 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. 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. 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.

Length and weight Northern pike in North America seldom reach the size of their European counterparts; one of the largest specimens known was a 21 kg (46 lb) 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. Northern Pike are capable of reaching a length of 140 centimeters and a weight of 25 kilograms. The largest Northern Pike on video was caught in the Netherlands, measuring 138 cm in length and over 23 kg in weight.

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 equation of the form

W = c L b . {\displaystyle W=cL^{b}.}

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). The relationship described in this section suggests a 50-centimetre (20 in) northern pike will weigh about 0.9 kg (2 lb), while a 65-centimetre (26 in) northern pike will weigh about 1.8 kg (4 lb).

Age Northern Pike typically live to 10–15 years, but sometimes up to 25 years.

Habitat

Pike are found in sluggish streams and shallow, weedy places in lakes and reservoirs, as well as in cold, clear, rocky waters. They are typical ambush predators; they lie in wait for prey, holding perfectly still for long periods, and then exhibit remarkable acceleration as they strike. They inhabit any water body that contains fish, but suitable places for spawning are also essential. Because of their cannibalistic nature, young pike need places where they can take shelter between plants so they are not eaten. In both cases, rich submerged vegetation is needed. Pike are seldom found in brackish water, except for the Baltic Sea area, here they can be found spending time both in the mouths of rivers and in the open brackish waters of the Baltic Sea. It is normal for pike to return to fresh water after a period in these brackish waters. They seem to prefer water with less turbidity, but that is likely related to their dependence on the presence of vegetation.

Geographic distribution

Esox lucius is found in fresh water throughout the Northern Hemisphere, including Russia, Europe, and North America. It has also been introduced to lakes in Morocco, and is even found in brackish water of the Baltic Sea, but they are confined to the low-salinity water at the surface of the sea, and are seldom seen in brackish water elsewhere..

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Northern pike

Start with the simplest possible case. Write down what Northern pike claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Northern pike before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Northern pike ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Northern pike

In research: Northern pike appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Northern pike in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Northern pike is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal taxa named by Carl Linnaeus, Cold water fish, Esox, so understanding it makes those chapters shorter.
In everyday life: Look for Northern pike outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Northern pike in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Northern pike means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Northern pike out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Northern pike in simple terms?

Why does Northern pike matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Northern pike?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Northern pike.