| fish lesions in the chesapeake bay: pfiesteria-like dinoflagellates and other etiologies. | ulcerative lesions and mass mortalities of atlantic estuarine fish, particularly menhaden (brevoortia tyrannus), have been associated with exposure to pfiesteria-like dinoflagellates and their toxins. we collected fish from the chicamacomico river, maryland, and observed solitary ulcerative lesions on the majority of menhaden sampled. one striped bass (morone saxatilis) had an area of reddening around the base of the dorsal fin. bluegill (lepomis machrochirus), channel catfish (ictalurus punctat ... | 1998 | 9601194 |