The medaka is a two-centimeter survivor that has ridden rice agriculture for millennia. It is the classic outdoor-tub fish of East Asia — breeding in every season and asking only for clean water and sunlight.
原生環境
生息地
Warm shallow paddies, ditches and tubs
水流
Still to very gentle
溶存酸素
Surface air-gap tolerant
レイアウトと設備
底床
Fine sand or bare bottom
流木・石組
Floating plants and a few twigs
水草
Dense floaters for fry survival
性格・餌・混泳
群泳性
8+; larger groups breed readily
餌
Omnivore; fine flakes and daphnia
おすすめの混泳相手
Other medaka — The more the merrier
White cloud minnow — Same cool-water niche
Nerite snails — Clean-up crew
混泳しないほうがいい相手
Anything with a big mouth — Medaka are bite-sized
Betta splendens — Bullied relentlessly
Strong currents — Exhausts them
繁殖と注意点
雌雄の違い
Males are smaller with longer fins; females swell noticeably with eggs
繁殖方法
Daily egg-layer; spawns among floating roots; eggs hatch in 1–2 weeks.