Perch
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 Yellow perch (Perca flavescens)
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In zoology, perch is the common name for freshwater ray-finned fish comprising the genus Perca of the family Percidae and order Perciformes, characterized by two dorsal fins, compressed body, prominent anal spines, and pelvic fins thoracic and with one spine and five soft rays. While these are the "true perches," the term also is used collectively for all members of the family Percidae, a group of over 200 species that also includes such taxa as the pikeperches (Sander sp., including the walleye. Sander vitreus) and the North American darters (four genera). The order Perciformes, which means "perch-like," also is often known as the perch order. This article will be on the genus Perca, which has three extant species.
Overview and description
Perciformes, the order to which perch belong, is the most diverse order of ray-finned fish (Actinopterygii). Indeed, about forty percent of all species of bony fish are in Perciformes. The name Perciformes comes from the Greek perke, meaning "perch," and the Latin forma, meaning "shape."
Percidae is one of the larger families in Perciformes, with 201 known species placed within ten genera. Member of Percidae are characterized by two dorsal fins, which are separate or narrowly joined (except for Zingel, in which they are broadly joined), and the pelvic fins, which are thoracic, have one spine and five soft rays. There are five to eight branchiostegal rays, the branchiostegal membrane is not joined to the isthmus. The largest member of the family is the walleye (Sander vitreus), which reaches up to 90 centimeters (35 inches) (Nelson 2006).
Nelson (2006) places the ten genera of Percidae into three subfamilies: Percinae, Luciopercinae, and Etheostomatinae. The genus Perca, or true perches, is part of the subfamily Percinae, along with the genera Gymnocephalus and Percarina. This subfamily is characterized by having prominent and usually well-developed anal spines, a well-developed swim bladder, a strongly serrate preopercle, and usually seven or eight branchiostegal rays (Nelson 2006).
The Perca genus has three species: Perca fluviatilis (Eurasian), P. flavescens (north America), and P. schrenki (Balkhash and Alakul' lades area of Asia). All are freshwater and found in the Northern Hemisphere (as characteristic for the family), but P. fluviatilis has been introduced into South Africa, Australia, and New Zealand. The Eurasian P. fluviatilis and the North American P. flavescens are nearly identical (Nelson 2006).
The type species for this genus is the European perch.
Overall, perch have a compressed body with "rough" or ctenoid scales. On the anterior side of the head are the maxilla and lower mandible for the mouth, a pair of nostrils, and two lidless eyes. On the posterior sides are the opercula, which are used to protect the gills. Also there is the lateral line system that is sensitive to vibrations in the water. They have a pair of pectoral and pelvic fins. On the anterior end of the fish, there are two dorsal fins. The first one is spiny and the second is soft. There is also an anal fin, which is also considered spiny, and a caudal fin. Also there is a cloacal opening right behind the anal fin. All perciform (Perciformeds) fish share the perch's general morphology.
Species
Most authorities recognize three species of perch:
- The European perch (Perca fluviatilis) is found in Europe and Asia. It is usually dark green with red fins. The European perch has been successfully introduced in New Zealand and Australia where it is known as the redfin perch or English perch.
- The Balkhash perch (Perca schrenkii) is found in Kazakhstan, (in Lake Balkhash and Lake Alakol), Uzbekistan, and China. It is very similar to the European perch, and grows to a comparable size.
- The Yellow perch (Perca flavescens), smaller and paler than the European perch, is found in the United States and Canada.
Perch as a food fish
Perch are a popular panfish and are considered to be very good eating; the commercial catch for them has always been in high demand. This has also led to considerable misuse of the term "perch" in the restaurant business in the United States, such as "ocean perch" (Rosefish) and "rock perch" (a small bass). Many restaurants will strive to correctly advertise the offering as "yellow lake perch", or the slightly more ambiguous "lake perch". "White perch", though good eating, is a completely different species of panfish common in New England, and not a member of the order Perciformes.
Angling
They can be caught with a variety of methods, but the two best methods are perhaps float fishing and lure fishing. Spinners work exceptionally well. When Float Fishing, the angler will want to have a disgorger at all times; Perch are notorious for swallowing the hook, and will need aid of a disgorger or forceps for unhooking. In many parts of the world they are also a favorite species among ice fishermen. They will take a variety of baits, including minnows, worms, maggots, bread and softshell crayfish.
Perch grow to around 5 lb (2.3 kg) or more, but the most common fish to be caught are around 1 lb (0.45 kg) or less, and anything over 2 lb (0.91 kg) is considered a prize catch.
ReferencesISBN links support NWE through referral fees
- Gilberson, Lance, Zooslogy Lab Manual 4th edition. Primis Custom Publishing. 1999.
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