BIOCHEMICAL INVESTIGATIONS OF SIPHLONURIDAE AND AMELETIDAE (EPHEMEROPTERA)

Thirteen European and four North American species of Siphlonuridae and Ameletidae were investigated biochemically using starch gel electroph oresis. Twenty enzyme loci were examined in 28 populations. In compari son with Siphlonurus aestivalis, S. croaticus exhibits different elect romorphs for two enzymes, and thus maintains the species status. Two c ommon electromorphs and high identity values with the other species of the S. aestivalis-group allow one to place S. flavidus in the S. aest ivalis-group. For three enzyme loci the Ameletus species share common electromorphs, different from those of Metreletus balcanicus. This fac t allows one to consider Metreletus as a valid genus. Because of the f ew common enzyme electromorphs and the low identity values, the Amelet us-Metreletus-complex should be separated from the Siphlonurus-Paramel etus-complex and included in the Family Ameletidae.