Perch

Resources

Perch are fish belonging to the class Osteicthyes, whose members have a bony skeleton rather than on made of cartilage. Bony fish comprise the largest group of vertebrates living today, both in the number of individuals (millions) and in the number of species (about 30,000). Perch of the genus Perca only occur fresh water, however several other fish commonly referred to as perch are found in marine environments. Perch live at depths in the oceans as great as 7 mi (11.5 km) and in mountain streams or lakes as much as 3 mi (5 km) above sea level.

Perch belong to Order Perciformes in the sub-class Actinapterygii, the ray-finned fish, whose fins are supported by jointed rays. These fish also have large eyes, no internal nostrils, and a swim bladder. The Perciformes are the largest order of fishes with about 150 families, roughly 1,400 genera, and over 7,000 species. Members of this order usually bear spines on their fins, have scales with serrated edges, and a tail fin with 17 rays. The Perciformes are the most diverse of all fish orders and are dominant forms in both marine habits (75% of the species) and freshwater habits (25% of the species). Members of the order Perciformes include swordfish, tuna, mackerel, gobies, blennies, mullets, cichlids, and remoras. Two suborders (Percoidei and Gobioidei) include well over half of all species of perch. The Percoidei is the largest suborder with about 3,524 species, many of which are desirable as human food-fishes, including striped bass, bluefish, snappers, barracudas, sunfishes, and perches. The family Percidae, with 10 genera and more than 200 species, includes all of the freshwater perches found in the northern hemisphere. Ninety percent of these species occur in North

KEY TERMS

Caudal fin— The tail fin of a fish.

Dorsal fin— A fin located on the back of a fish.

Fin— Appendage used to stabilize swimming movements.

Pectoral fin— Breast fin.

Ventral fin— Belly fin.

America east of the Rocky Mountains and most of these are darters. The vertebrae of perch number between 32 and 50; the largest species is the Walleye measuring some 90 cm (3 ft).

The genus Perca includes all freshwater perch and has three species: Perca fluviatilis, a Eurasian species; the yellow perch, Perca flavescens of North America; and Perca shrenki of Asia. All three species are generalized forms that probably represent the ancestral type from which the other species were derived.

The Old World counterpart of the yellow perch is the European perch, Perca fluviatilis. The two species are extremely similar and are separable only by minor differences; consequently, the classification of these two forms as two species or a single species is controversial.

The yellow perch is the preferred freshwater fish of many commercial fisheries in the United States. In the Great Lakes region of the United States and Canada commercial fisheries take between 5,000 and 10,000 tons of yellow perch per year from Lake Erie. This tonnage fluctuates from year to year due to fish population changes and to economic factors involved in delivering the catch to consumers. In Europe, perch are more popular as a sport fish than a commercial fish. Perch are very popular sport fish in Finland and in land-locked countries such as Switzerland. They are less popular in Great Britain and other countries with a significant salmon fishery.

Resources

BOOKS

Craig, J.F. The Biology of Perch and Related Fish. London: Croom Helm, 1987.

Nelson, Joseph S. Fishes of the World. New Jersey: John Wiley & Sons, Inc., 2006.

OTHER

University of Wisconsin Sea Grant Institute. “Yellow Perch.” February 11, 2002. <http://www.seagrant.wisc.edu/greatlakesfish/yellowperch.html> (accessed October 25, 2006).

Perch

Perch belong to the class Osteicthyes, whose members have a skeleton of bone rather than cartilage. Bony fish comprise the largest group of vertebrates living today, both in the number of individuals (millions) and in the number of species (about 30,000). Perch occur in both fresh water and sea water throughout the entire world. Perch live at depths in the oceans as great as 7 mi (11.5 km) and in mountain streams or lakes as much as 3 mi (5 km) above sea level .

Perch belong to Order Perciformes in the sub-class Actinapterygii, the ray-finned fish , whose fins are supported by jointed rays , and which have large eyes, no internal nostrils, and a swim bladder. The Order Perciformes is the largest order of fishes, with 150 families, 1,367 genera, and 7,791 species. Members of this order usually bear spines on their fins, have scales with serrated edges, and a tail fin with 17 rays. The Perciformes are the most diverse of all fish orders and are dominant forms in both marine habits (75% of the species) and freshwater habits (25% of the species). Members of the order Perciformes include swordfish , tuna , mackerel , gobies , blennies , mullets, cichlids, and remoras. Two suborders (Percoidei and Gobioidei) include well over half of all species of perch. The Percoidei is the largest suborder with about 3524 species, many of which are desirable as human food-fishes, including striped bass , bluefish, snappers, barracudas, sunfishes, and perches. The family Percidae, with 9 genera and 146 species, includes all of the freshwater perches found in the northern hemisphere. Ninety percent of these species occur in North America east of the Rocky Mountains and most of these are darters. The Order Perciformes is characterized by two dorsal fins, one or two anal spines, and pelvic fins on the ventral, anterior trunk, with the base of the pelvic fin located forward of the pectoral fin. The vertebrae of perch number between 32 and 50; the largest species is the Walleye measuring some 90 cm (3 ft).

The genus Perca has three species: Perca fluviatilis, a Eurasian species; the yellow perch, Perca flavescens of North America; and Perca shrenki of Asia . All three species are generalized forms that probably represent the ancestral type from which the other species were derived.

The Old World counterpart of the yellow perch is the European perch, Perca fluviatilis. The two species are extremely similar and are separable only by minor differences; consequently, the classification of these two forms as two species or a single species is controversial.

The yellow perch is the preferred freshwater fish of many commercial fisheries in the United States. In the Great Lakes region of the United States and Canada commercial fisheries take between 5,000 and 10,000 tons of yellow perch per year from Lake Erie. This tonnage fluctuates from year to year due to fish population changes and to economic factors involved in delivering the catch to consumers. In Europe , perch are more popular as a sport fish than a commercial fish. Perch are very popular sport fish in Finland and in land-locked countries such as Switzerland. They are less popular in Great Britain and other countries with a significant salmon fishery.

Resources

books

Craig, J.F. The Biology of Perch and Related Fish. London: Croom Helm, 1987.

Rosen, Kenneth. Elementary Number Theory and Its Applications. 4th ed. Boston: Addison-Wesley, 2000.

Whiteman, Kate. World Encyclopedia of Fish & Shellfish. New York: Lorenz Books, 2000.

KEY TERMS

Caudal fin

—The tail fin of a fish.

Dorsal fin

—A fin located on the back of a fish.

Fin

—Appendage used to stabilize swimming movements.

Pectoral fin

—Breast fin.

Ventral fin

—Belly fin.

perch¹ / pərch/ • n. a thing on which a bird alights or roosts, typically a branch or a horizontal rod or bar in a birdcage. ∎  a place where someone or something rests or sits, esp. a place that is high or precarious: Marian looked down from her perch in a beech tree above the road.• v. [intr.] (of a bird) alight or rest on something: a herring gull perched on the mast. ∎  (of a person) sit somewhere, esp. on something high or narrow: Eve perched on the side of the armchair. ∎  (be perched) (of a building) be situated above or on the edge of something: the fortress is perched on a crag in the mountains. ∎  [tr.] (perch someone/something on) set or balance someone or something on (something): Peter perched a pair of gold-rimmed spectacles on his nose.PHRASES: knock someone off their perch inf. cause someone to lose a position of superiority or preeminence: will this knock London off its perch as Europe's leading financial center?perch² • n. (pl. same or perches ) an edible freshwater fish (genus Perca) with a high spiny dorsal fin, dark vertical bars on the body, and orange lower fins. Its three species include the yellow perch (P. flavescens) of North America. The perch family also includes the pikeperches, ruffe, and darters. ∎  used in names of other freshwater and marine fishes resembling or related to this, e.g., climbing perch.perch³ • n. chiefly Brit., hist. a linear or square rod; see rod, sense 3.

perch. Small bracket or corbel such as those found near an altar in a church to carry a reliquary, statue, etc. Also called pearc or pearch.

perch former name for a measure of length, especially for land, equal to a quarter of a chain or 5¹/₂
yards (approximately 5.029 m). Recorded from Middle English, the word comes via Old French from Latin pertica ‘measuring rod, pole’.