CINCINNATI, OHIO (WNCN) — The Cincinnati Zoo’s famous Fiona the Hippo has a new sibling, and you have a chance to help name the calf.

The baby hippopotamus, which arrived Wednesday night, was something of a surprise since Bibi, the mother, was on birth control when she was found to be pregnant around April Fool’s Day earlier this year, according to the zoo.

Zoo officials said in a statement that both Bibi and the calf are doing well.

Unlike Fiona, who was born prematurely, her sibling arrived at full term, according to officials.

“This calf looks huge to us because Fiona, Bibi’s first baby, only weighed 29 pounds when she was born six weeks premature and wasn’t able to stand on her own. This new calf weighs at least twice as much as Fiona did and is already walking,” said Christina Gorsuch, Cincinnati Zoo’s director of animal care.

At five years old, Fiona now weighs 2,000 pounds, the zoo said.

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The new addition is being monitored carefully.

“We’re not sure if nursing has occurred yet because the water is murky,” Gorsuch said. “It’s Bibi’s first time nursing since Fiona had to be cared for by the hippo staff, so we’re keeping a close eye on them to make sure we don’t need to step in.”

The baby hippo hasn’t been given a name yet, but the zoo is taking suggestions.

“Bibi and the baby, yet to be named, will spend the next two weeks bonding behind the scenes,” said Gorsuch. “A female would take her newborn away from the bloat for about that amount of time in the wild, and we try to give Bibi the choice to do what feels natural to her.” 

The zoo saw an increase in visitors and social media views after Fiona’s birth, and some animal rights groups criticized it for marketing a captive animal.

The zoo said Bibi and her new baby will not be seen by the public right away, but the zoo plans to share any photos and videos that can be taken without disturbing them. 

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The Associated Press contributed to this report.