Choice matters: Incipient speciation in Gyrodactylus corydori (Monogenoidea: Gyrodactylidae)

► Gyrodactylus corydori may be undergoing incipient speciation on sympatric hosts. ► Gyrodactylus corydori appears to be undergoing disruptive selection. ► Low specificity within viviparous Gyrodactylidae may result in sympatric speciation.