亜種[ashu] subspecies
異機種[ikishu] heterogenous equipment
異種[ishu] different kind (species, variety)
育種[ikushu] (plant) breeding
育種家[ikushuka] (plant) breeder

育種所[ikushujo] (plant) nursery
一種[isshu] species
一粒種[hitotsubudane] an only child
種違い[tanechigai] half-brother
艶種[tsuyadane] love affair

異類[irui] varieties
一類[ichirui] same kind
円虫類[enchuurui] round worms
塩類[enrui] salts
塩類溶液[enruiyoueki] saline

貝類[kairui] shellfish
柑橘類[kankitsurui] citrus fruits
希土類[kidorui] rare earth
魚貝類[gyokairui] marine products
魚類[gyorui] fish