The general killifish is called Japanese killifish, and the length is approximately 3-4cm. The surface of a body is gray and dark brown. It lives in a freshwater inhabiting widely from the north to the south of Japan.
・Japanese killifish
The origin of the name of killifish came to be called "medaka"by the big eyes that are characteristic beings on the head.
It inhabit a brook or the waterway and lay eggs from spring to the summer
and it hang the fry in autumn from summer and eat plankton or a mosquito larva and grow up. For this ovipositional cycle, it is correct for a cycle of
rice. The life is in the nature for 1-1.5 years, but becomes for 3-5 years
artificially.
・Killifish except the Japanese killifish
Killifish different in colors of the body is rarely born with variant.
Ddifferences in colors of the body are himedaka (scarlet killifish), shiromedaka
(white killifish), aomedaka (blue killifish). Some differences are made
by gene manipulation like Hikari killifish, albino killifish, in addition, various variations.