What is "perca fluviatilis"

Perch \Perch\ (p[~e]rch), n. [Written also pearch.] [OE. perche, F. perche, L. perca, fr. Gr. pe`rkh; cf. perkno`s dark-colored, Skr. p[.r][,c]ni spotted, speckled, and E. freckle.] (Zo["o]l.)

1. Any fresh-water fish of the genus Perca and of several other allied genera of the family Percid[ae], as the common American or yellow perch ( Perca flavescens syn. Perca Americana), and the European perch ( Perca fluviatilis).

2. Any one of numerous species of spiny-finned fishes belonging to the Percid[ae], Serranid[ae], and related families, and resembling, more or less, the true perches. Black perch.

   1. The black bass.

   2. The flasher.

   3. The sea bass.

      Blue perch, the cunner.

      Gray perch, the fresh-water drum.

      Red perch, the rosefish.

      Red-bellied perch, the long-eared pondfish.

      Perch pest, a small crustacean, parasitic in the mouth of the perch.

      Silver perch, the yellowtail.

      Stone perch, or Striped perch, the pope.

      White perch, the Roccus Americanus, or Morone Americanus, a small silvery serranoid market fish of the Atlantic coast.