Evolutionary relationship amongBothriocephalus parasitized in grass carpCtenopharyngodon idellus (C. et V.), common carpCytpinus carpio L. and Ma Kou YuOpariichthys bidens Günther in China

RAPD was used to analyze the polymorphism ofBothriocephalus parasitic in grass carp and common carp from Guangdong, Fujian and Gansu and in Ma Kou Yu from Fujian. Though there exist differences in geographical distribution and host specificity betweenBothriocephulus parasitic in grass carp and common carp, RAPD analysis shows high similarity (72.3%–96.3%) in DNA between them, whereas betweenBothriocephalus parasitic in Ma Kou Yu and in grass carp and common carp low similarity (24%-28.2%) was noticed. Hence,Bothriocephalus parasitic in Ma Kou Yu andBothriocephalus parasitic in grass carp and common carp should be regarded as separate species.