Another cownosed stringray has died at the Calgary Zoo, bringing the total number of stingray deaths at the zoo since Sunday to 35.
Zoo keepers have said they are keeping a close eye on the remaining stingrays -- down to eight -- as they try to determine what is behind the mysterious deaths, which began to occur Sunday afternoon. Zoo officials say that two of the surviving stingrays remain in critical condition, while six others are improving.
Veterinarians at the zoo are now waiting for the results of preliminary tests on the water in the tanks that housed the zoo's stingray population, which had numbered 43 before the deaths. But officials say it may be up to two months before they get detailed toxicology reports.
The animals were part of the Calgary Zoo's newest exhibit, which cost $250,000 to set up. On Sunday afternoon staff noticed the stingrays were acting strangely and within hours most were dead.
The stingray exhibit opened in February, drawing thousands of visitors every day. It's now closed while zoo officials try to figure out what went wrong.
The stingray deaths are the latest tragedy to hit the zoo. Three gorillas died last year at the facility, and last fall, a six-year-old hippo died just hours after it had been transported from a zoo in Denver.
Officials have said the tragedies are unrelated.
With files from The Canadian Press
