Kalmar "fucoid algae" tana nufin ƙungiyar algae mai launin ruwan kasa da ke cikin dangin Fucaceae. Ana samun waɗannan algae a cikin ruwan sanyi da sanyi, kuma ana siffanta su da launin ruwan kasa-kore da rassansu, ribbon-kamar thallus (jiki). Fucoid algae an san su da mahimmancin muhalli, saboda suna ba da wurin zama da abinci ga yawancin halittun ruwa, kuma suna taka muhimmiyar rawa a cikin yanayin yanayin ruwa.