The world's first manta ray ever born in captivity has died at an aquarium in southern Japan after being attacked by its father, officials said yeserday.

The baby manta, a female about 1.9m wide, was born last Saturday at the Okinawa Churaumi Aquarium, drawing worldwide attention.

But it was found dead early yesterday, according to Minoru Toda, a spokesman for the aquarium on the subtropical island of Okinawa.

"I have never seen such a thing but the father manta ray kept chasing the newborn baby from behind. The baby looked stunned and bumped into walls at times," Toda said.

"The baby also collided with a 7.5m whale shark which was bred in the same tank," he added. "The baby had many bruises. It was hurt in the right eye and there was bleeding in the internal organs."
"It was unfortunate to lose the baby. But we have learned a lot from the experience and we can expect to have better results next time," Toda said.

The aquarium has been keeping two male mantas for 15 years each and two females for eight years each. The mother manta, 4.2m long, mated with a male on June 8 last year.

"We presume that the male mantas were newly born when we captured them and it has taken so long for them to mature," Toda said. "We can expect them to breed every year from now."

Manta rays are the largest of the rays, and live in tropical waters, usually near coral reefs.