TOKYO (AFP)-A Japanese zoo has culled 57 native snow monkeys by lethal injection after finding that they carried genes of an "invasive alien species", officials said Tuesday.
The Takagoyama Nature Zoo in the city of Futtsu in Chiba prefecture east of Tokyo, housed 164 simians which it believed were all pure Japanese macaques.
But the operator and local officials discovered about one-third were crossbred with the rhesus macaque, which in Japan is designated an "invasive alien species".
A city official told AFP on Tuesday that Japanese law bans the possession and transport of invasive species, including the crossbreeds, and that culling of them is allowed under the law.
He said the monkeys were put to death by lethal injection over about one month ending early February.