Thalassiosira leptopus is a species of . They are native to Pará, Rio Grande Do Norte, Bahia, Alagoas, SãO Paulo, Rio Grande Do Sul, Paraná, Rio De Janeiro, 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).