Lake Shelby, an 829-acre natural lake, located in Baldwin County at Gulf Shores, Alabama was treated with emulsifiable rotenone in October, 1956 to eliminate an undesirable fish population. The lake was restocked with the bluegill sunfish, Lepomis macrochirus; the redear sunfish, Lepomis microlophus; and the largemouth bass, Micropterus salmoides. Subsequent population examinations following restocking revealed in 1958 that a copepod was infesting the gills of the fish. Collection of specimens and identification revealed the copepod to be Ergasilus lizae Krøyer previously reported only from marine hosts. A description and history of Lake Shelby is given. The taxonomy and morphology and observations on the life cycle of Ergasilus lizae are also presented.
