New records and redescriptions of American species of Mesocyclops and of Diacyclops bernardi (Petkovski, 1986) (Copepoda: Cyclopoida)

Recent collections in the south central U.S.A. have included three neotropical and one probably introduced species that are presently assigned to the cyclopoid copepod genus Mesocyclops. Mesocyclops longisetus var. curvatus Dussart, 1987, is reported from Louisiana, U.S.A., and Panama; published records of Mesocyclops longisetus (Thiébaud, 1914) sensu lato in the southern U.S.A. are reviewed. Mesocyclops reidae Petkovski, 1986, is reported from Mississippi, U.S.A., and Honduras. Mesocyclops ruttneri Kiefer, 1981, is redescribed from type specimens collected in Austria, and newly reported from Louisiana, Mississippi, China, Thailand, and Viet Nam. This species is considered to have been introduced from Asia into Austria and the U.S.A. Mesocyclops bernardi Petkovski, 1986, newly recorded from Louisiana and Mexico, is transferred to the genus Diacyclops.