Esox in the context of "Andvari"

A piscivore (/ˈpɪsɪvɔːr/) is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory.

Almost all predatory fish (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lions, and crocodilians, are not completely piscivorous; often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish, while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, cetaceans, spiders, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fish as significant if not dominant portions of their diets. Humans can live on fish-based diets, as can their carnivorous domesticated pets such as dogs and cats.

The northern pike (Esox lucius), also known as pickerel, jack 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.

A spinnerbait or spinner is any one of a family of hybrid fishing lures that combines the designs of a swimbait with one or more spoon lure blades. Spinnerbaits get the name from the action of the metallic blades, which passively revolve around the attachment point like a spinning propeller when the lure is in motion, creating varying degrees of vibration and flashing that mimic small fish or other preys of interest to large predatory fishes. The two most popular types of spinnerbaits are the in-line spinner and safety pin spinnerbait, though others such as the tail spinner also exist. Spinnerbaits are used principally for catching freshwater fishes such as perch, pike and bass.

A quiver tip is a flexible extension to a fishing rod which is designed to vibrate, or quiver, when a fish takes the bait. The main characteristic of its design is its sensitivity. It is a popular and very effective method of bite indication both on still and running water, and is used far more often in bottom fishing. It is not used in game fishing (i.e. for salmon, trout and sea trout) and is seldom, if ever, used when fishing for very large coarse fish (e.g. carp or pike). In essence, the angler watches the tip of the fishing rod to detect bites as opposed to, say, a float or an electronic bite alarm.

The Vyatka is a river in Kirov Oblast and Tatarstan in Russia. It is a right tributary of the Kama. It is 1,314 kilometres (816 mi) long, and its drainage basin covers 129,000 square kilometres (50,000 sq mi).

The Vyatka begins in the northern parts of Udmurtia. It freezes over in the early November and remains so until the second half of April. The Vyatka teems with fish, including bream, roach, tench, sheat fish, pike, European perch, zander, etc.

The Amur pike (Esox reichertii), also known as the blackspotted pike, is a pike native to the Amur River system in east Asia, as well as freshwater habitat on the island of Sakhalin. Closely related to the northern pike, it reaches a length of 115 cm (3 ft 9 in), a weight of 12.5 kg (28 lb), sporting a silvery body with small, black spots. Like other pike, this species is prized for sport fishing.

It is not commonly found outside its native range. However, it was introduced to Glendale Lake, Cambria County, Pennsylvania (United States), by the Pennsylvania Fish and Boat Commission (PFBC) in 1968. The lake is just south of the native range of the northern pike. Pure Amur pike were last spawned in 1971. All of the Pennsylvania Fish Commission's brood stock was lost in the summer of 1976. That same year the world record Amur pike was caught from the lake. The year after, the PFBC also stocked 168 northern pike x Amur pike hybrids into the lake. With a lack of success, the Amur pike program was cancelled. Glendale Lake was chosen because its outflow leads into heavily polluted waters in which fish cannot survive. Pure northern pike are found in the lake today, however it is likely no pure or hybrid Amur pike remain.

The walleye (Sander vitreus, synonym Stizostedion vitreum), also called the walleyed pike, yellow pike, yellow pikeperch or yellow pickerel, 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 color morph that was once found in the southern Ontario and Quebec regions, but is now presumed extinct. 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.

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 members of the family Esocidae. It is also sometimes called a dory in British English (and its common name in French is the similar doré—meaning golden or gilded), although this name is also used for various other species.