Biometric comparision of the frontal knob in american populations of Artemia (Anostraca, Artemiidae)

The frontal knob diameter and its relationship with the total body lenght a mong populations of Artemia franciscana (Chile and U.S.A), A. persimilis (A rgentina), and Artemia sp. (Chile), were asessed. All populations were cult ured under laboratory conditions. Significant differences in both parameter s between A. franciscana and Artemia sp, from Salina el Convento (Chile), a nd between A. persimilis and Artemia sp. from Amarga Lagoon (Chile) were re corded. Geographical, ecological and genetic aspects which affected the spe ciation of Artemia populations in Chile and Argentina, and their expression in morphometric characters are discussed.