Bisexual populations of the brine shrimpArtemia in Sète-Villeroy and Villeneuve Saltworks (Languedoc, France)

Abstract

So far,Artemia populations in solar saltponds of southern France have been considered as belonging to the Old World parthenogenetic strain. However, two populations sampled monthly in abandoned salinas of Sete-Villeroy and Villeneuve appear to be bisexual throughout their life-cycle. Their sex ratio regularly fluctuates near equilibrium, and mating, present throughout life, is very common in early winter. Morphological characteristics, particularly the male frontal knobs structure, are discussed in relation to the diploid bisexual Mediterranean strain,Artemia tunisiana, which is distributed around the Mediterranean basin. The existence of sexual populations is discussed in regard to variation in environmental conditions in abandoned salinas.