Cincinnati Zoo baby hippo update: Fiona has been taken off oxygen

A growing Fiona has been taken off supplemental oxygen, Cincinnati Zoo officials said.

The baby hippo’s lungs are almost fully developed as she has been learning to dive and hold her breath in the pool, Cincinnati Zoo hippo handler Wendy Rice said in an official zoo blog post.

PHOTOS: 9 adorable Instagrams from Ohio zoos that will melt your heart

The premature baby hippo had been on oxygen since she was 8 days old. Lungs are often the last organ to develop in premature mammals, Rice said.

WATCH: Baby hippo Fiona takes her first steps

Hippopotamus babies are typically born underwater, which allows them to learn to hold their breath, according to Rice. That’s important, she said, because mother hippos spend most of their time in water.

For Fiona, though, the instinct was dangerous.

MORE: Fiona reaches another milestone on journey to meet her parents

Early on, she would exhibit dive responses while resting and sleeping, according to Rice. Fiona would close her nostrils and simply hold her breath for seconds and seconds on end.

“The episodes all ended the same way: Fiona’s little nostrils would finally burst open for exhalation and her eyes would open and roll into focus as if to say ‘what happened?!’ ” Rice wrote in the zoo’s blog.

At eight weeks, Fiona began wearing a cannula — a tube that delivers oxygen — when she was napping or resting. That helped improve her breathing almost immediately, Rice said.

RELATED: Zoo Plans for cheetah facilities in Warren County on hold

Fiona can now dip her face below the water for up to 20 seconds, Rice said.

Fiona will eventually be able to hold her breath underwater for two to three minutes as a juvenile. She will be able to hold her breath for up to five minutes once she reaches adulthood.

As Fiona’s health improves, the keepers said they are looking forward to introducing her to her parents, Bibi and Henry.

ExploreDownload the free Journal-News app, Butler County’s #1 source for local news