Perca is the genus of fish referred to as perch or yellow perch, a group of freshwater fish belonging to the family Percidae.
Perch have "rough" or 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, and 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 an anal fin, which is also considered spiny, and a caudal fin.
Also there is a cloacal opening right behind the anal fin.
Frog zoology About 400 million years ago, some members of the sarcopterygian group of fish moved onto land. These became the first amphibians. Today, these ... >
read more
Crappie The species of this genus are known as crappies and are extremely popular game fish. The genus has two species the white and black crappie. Crappie ... >
read more
Giant Otter The giant otter is the largest of the world's otters. It is native to South America but is endangered and is also very rare in captivity. The Giant ... >
read more
Striped bass Striped bass are members of the temperate bass family which include white perch and white bass. Striped bass are a popular game fish and they are ... >
read more
Hawk The term hawk refers to birds of prey. In February 2005 the Canadian scientist Dr Louis Lefebvre announced a method of measuring avian IQ in terms of ... >
read more
Marlin The marlin is a large game fish. It has an elongated body, up to 2.5 m long, a spearlike snout, and a long rigid dorsal fin, which extends forwards ... >
read more
Pollock Pollock is the common term for either of the two species in the Pollachius genus. Both P. pollachius and P. virens are commonly referred to as ... >
read more
Cod Cod is the common name for the genus Gadus of fish, belonging to the family Gadidae, and is also used in the common name of a variety of other ... >
read more
Swordfish Swordfish are large, highly migratory, predatory fish characterized by a long, flat bill in contrast to the smooth, round bill of the marlins. ... >
read more
Fish migration Many types of fish undertake migrations on a regular basis, on time scales ranging from daily to annual, and with distances ranging from a few meters ... >
read more