GENETIC DISTINCTION OF LARUS-ARGENTATUS, L-FUSCUS AND LARUS-CACHINNANS

The mitochondrial cytochrome b gene of Larus argentatus, L. fuscus and L. cachinnans michahellis was amplified by PCR and partially sequence d. Sequence analysis by PAUP 3.1 indicated that L. argentatus and L. c achinnans are genetically distinct and separated by 2 % base exchanges . L. cachinnans seems to be closer related to L fuscus than to L. arge ntatus. The three taxa represent a superspecies. Our data imply that g ene flow between the 3 gull species must be negligible and furthermore , that they represent rather young species which may have split 100 00 0-500 000 years ago. The recognition of L. cachinnans as a distinct sp ecies is supported by molecular evidence.