Bantu, a 220-kilogram endangered gorilla who lived in the Mexico City zoo, has died after going into cardiac arrest when he was sedated in order to be moved to another zoo to try to mate, city authorities said on Thursday.
A western lowland gorilla, Bantu, 24, was born in captivity in Mexico City's Chapultepec zoo, where he was one of the star attractions.
He had failed to mate with three females in the zoo, so zoo officials organised for him to travel to the zoo in the central Mexican city of Guadalajara, where there were two other females.
However, at around 9.30 pm on Wednesday, after being administered a sedative, Bantu went into cardiac arrest, Mexico City's environmental ministry said in a statement.
For 30 minutes, vets tried to resuscitate him but to no avail.
Lowland gorillas are critically endangered with fewer than 175,000 left in the wild, according to the International Union for Conservation of Nature (IUCN). They can live into their 50s and even up to 60 years old in captivity.
"The Chapultepec zoo is in mourning, and deeply regrets the death of Bantu," the statement said.