The first of two pregnant walruses at Quebec's City's aquarium has given birth.

The aquarium says it's the first time in Canada a captive walrus has delivered a live full-term baby. 

Twelve-year-old Arnaliaq gave birth naturally and without human interference Saturday morning.

The sex of the baby is not yet known.

Only 19 walruses are believed to have become pregnant in captivity in North America since 1930, including two at the Aquarium du Quebec. Of the 19, Arnaliaq is the seventh to give birth.

The second pregnant female, Samka, is due at the beginning of June.