Japanese rice fish

Medaka ( Oryzias latipes )

The medaka, also Japanese rice fish or medaka ( Oryzias latipes ) is a Southeast Asian fish from the family of rice fish ( Adrianichthyidae ), which is as aquarium fish and a model organism in biological research of importance.

Features

Medaka attain a length of up to about three and a half centimeters. Your body is flattened laterally, the head accounts for about a quarter of the standard length of. The mouth is terminal with about the same length or slightly longer jaws lower jaw. The eyes are medium in size and not protrude above the top of the head. The scales are relatively large cycloid scales, of which lie along the body 28 to 32. The body is translucent with scattered, dark melanophores that form distinct dark rows from the back of the head to the neck of the dorsal fin and on the flanks of the head more or less to the tail fin. The gill cover and the peritoneum are silvery; the latter is in the females approximately rectangular, smaller in males and triangular. The dorsal fin has 5-7 rays, the anal fin has 17 extended to 22 In the males are the rays of both fins and between the last two rays of the dorsal fin is a distinct notch. The pectoral fins have 9 to 11 and the pelvic fin 5-7 rays, which are elongated in the female part and almost to the anal fin. The caudal fin has in the upper and lower half of each one undivided and four or five articulated rays, and dorsal and ventral five six prokurrente rays. The number of Branchiostegalstrahlen is between five and six that the vortex at 27 to 32

Occurrence

The Medaka comes from Laos and Vietnam to the East China and Korea and the Japanese islands of the Ryukyu Islands to Honshu before. He settled mostly standing or slowly flowing fresh and brackish waters such as ponds or rice fields.

Taxonomy

The medaka was described in 1846 by Coenraad Jacob Temminck and Hermann Schlegel scientifically as Poecilia latipes. 1866, the type of Alber Günther was assigned to a genus Haplochelus and provided by David Starr Jordan and John O. Snyder in the genus Aplocheilus 1901. 1906 described Jordan and Snyder then the genus Oryzias the medaka as the sole and type species, which differs from Aplocheilus by the absence of teeth on the vomer. In fact, absent in the genus Oryzias the vomer. The genus name Oryzias refers to the occurrence of fish in rice fields ( Oryza genus name ), the specific epithet latipes derives from Latin latus ( wide) and pes ( foot ) ago.