Polymerase chain reaction
PCR was set up in 5Opl volume as described in a thermal cycler . The temperature profile for the amplification of the two rRNA gene fragments was 95°C for 30 s, 40°C for 1 min and 72°C for 1 min for ten cycles followed by twenty-five cycles of 95°C for 30 s, 50°C for 1 min and 72°C for 1 min. For the amplification of the NADH dehydrogenase and the COI gene fragments, the temperature profile was 95°C for 30 s, 45°C for 1 min and 72°C for 1 min for thirty-five cycles. For both temperature profiles, an initial denatur- ation step of 95°C for 3 min and a final extension step of 72°C for 7
min were added. After amplification, the products were electrophoresed on 1 Yo agarose gels containing 50,d per litre of 10 mglml ethidium bromide. No contamination was detected in negative
controls.