Genetic structure ofAnisakis physeteris, and its differentiation from theAnisakis simplexcomplex (Ascaridida: Anisakidae)

Abstract

SUMMARYThe genetic structure ofAnisakis physeterisfrom the Mediterranean Sea has been analysed electrophoretically at 22 enzyme loci. The samples studied, although differing in the life-stage (larvae and adults), and in the host (the fishesMicromesistius poutassouandTrachurus trachurus, and the sperm whalePhyseter macrocephalus) were genetically homogeneous. Of these loci 11 (Ldh, Sod, Np, Adk-2, Pgm-1, Est-1, Est-2, Acph-1, Acph-2, Lap-2andCa) were found to be monomorphic, while the other 11 (Sdh, Mdh, ldh, 6-Pgdh, G3pdh, Got, Adk-1, Pgm-2, Lap-1, MpiandGpi) showed from 2 to 7 alleles. The following values of genetic variability were estimated:He= 0·ll,P= 0·50,A= 1·95. Distinct alleles were found betweenA. physeterisand theA. simplexcomplex at 19 out of the 22 loci studied, and only few rare alleles were shared at the remaining 3 loci. The genetic divergence betweenA. physeterisandA. simplexA and B is therefore very high, the values of Nei’s indexDbeing 7·384 and 6·443 respectively (I= 0·001 and 0·002). The assignation ofA. physeterisand theA. simplexcomplex to two distinct subgenera,SkrjabinisakisandAnisakis, as proposed by Mosgovoy on a morphological basis, appears to be fully justified according to our genetic data.