Chaetoceros affinis is a species of . They are native to Rio De Janeiro, Sergipe, ParaíBa, Rio Grande Do Sul, Paraná, Espirito Santo, SãO Paulo, Alagoas, Rio Grande Do Norte, and Pernambuco.
Definition: Living in the fluid medium (water or air) but unable to maintain their position or distribution independently of the movement of the water/air mass (adapted from Lincoln et al., 1998).