Note sur la biogéographie de la biodiversité du genre Artemia dans la région ouest de l’Afrique du Nord (Algérie, Maroc et Tunisie)

Abstract

The crustacean Artemia (Branchiopoda, Anostraca) is one of the most common inhabitants of aquatic hypersaline, coastal and/ or continental lakes, lagoons and saltworks. With the indispensable use of its nauplii in marine aquaculture, the cysts of Artemia have become a natural resource of great commercial importance, which has led to the need to study its biodiversity and to know its biogeography, in order to provide and establish its commercial exploitation as a resource. Although the biogeography of species and populations of Artemia is known in the Mediterranean area, its distribution in the countries of North Africa is not yet well established. During the last decades great efforts have been made in this regard, especially in countries such as Algeria, Morocco and Tunisia, where we have verified the existence of a pattern of biodiversity similar to that described in the European Western Mediterranean, represented mainly by three common forms : the sexual species Artemia salina (Leach 1758) and the two parthenogenetic strains (A. parthenogenetica Barigozzi, 1980) : diploid and tetraploid. Furthermore, the exclusive use of cysts of the species from America A. franciscana (Kellogg 1906) in marine aquaculture and its commercial generalization, has conducted to the introduction of this exotic species in the Mediterranean basin, taking the profile of an invasive species, and leading to the elimination of native strains by a simple competition phenomenon. This potential threat on the diversity of the genus can also affect the North African countries today, where we have verified the presence of some populations of the American species in Morocco, and in Tunisia.