Minnesota Zoo looses another dolphin!

The Minnesota Zoo has lost another dolphin.Rio, the zoo's oldest female dolphin, died Monday night. She was 35. Zoo officials were running tests to determine the cause of death.The Atlantic bottlenose dolphin arrived at the Minnesota Zoo in 1980 from the New York Aquarium.

During her 26 years at the zoo, Rio gave birth to four calves.One of Rio's calves, Harley, died in January after fracturing his skull when he jumped out of the water and hit his head on the concrete deck.The zoo has four Atlantic bottlenose dolphins left.