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A perch is a freshwater
bony fish belonging to the family Percidae. Perch, of which there
are three species, lend their name to the largest order of vertebrates:
the Perciformes, from the Greek perke meaning perch, and the Latin
forma meaning shape. All perciform fish share the perch's general
morphology. The European perch (Perca fluviatilis) is found in
Europe and northern Asia. It is 15-60 cm long, and may weigh up
to 10.4 kg. It is usually dark green with red fins. It has been
successfully introduced in New Zealand and Australia where it
is called redfin perch. The Balkhash perch (Perca schrenkii) is
found in Kazakhstan; in Lake Balkhash and Lake Alakol. It is very
similar to the European perch, and grows to a comparable size.
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Perch have ctenoid
scales. When looking through a microscope, the scale look like
a plate with growth rings and spikes on the top edges. Externally
the anatomy of perch is simple enough. On the dorsal side of the
fish, there consists a upper maxilla and lower mandible for the
mouth. A pair of nostrils. Two lidless eyes. On the posterior
sides are the operculum, which are used to protect the gills.
Also there is the lateral line system which 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 a caudal fin
and anal fin. Also there is a cloacal opening right behind the
anal fin. The perch spawns at the end of April or beginning of
May, depositing it upon weeds, or the branches of trees or shrubs
that have become immersed in the water;
Pictures 1 To 4 Come From The U.S. Fish & Wildlife Service
Pictures 5 To 6 Are Courtesy of The U.S.D.A.
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