Genetic heterogeneity within populations of Lepeophtheirus europaensis (Copepoda: Caligidae) parasitic on two host species

, and 1992. Genetic heterogeneity within populations of Lepeophtheirus europaensis (Copepoda: Caligidae) parasitic on two host species. International Journal for Parasitology 22: 1179–1181. The ectoparasitic copepod Lepeophtheirus europaensis exploits two different species of Mediterranean flat fishes: the brill (a marine fish) and the flounder (found in lagoons). Analysis of the genetic structure of these parasite populations revealed that migration is reduced between the two hosts. Moreover, an adaptive polymorphism was found when the survival of the eggs and free larvae of these copepods was studied at different salinities. The results are discussed and interpreted as signs of a probable speciation process currently occurring within this parasite taxon.