Shark pregnancies can last an incredibly long time, with the frilled shark holding the biological record by carrying its pups for a torturous three and a half years before giving birth.

A closer look

Shark pregnancies can last an incredibly long time, with the frilled shark holding the biological record by carrying its pups for a torturous three and a half years before giving birth. Unlike most fish, sharks often produce a small number of highly developed young rather than thousands of fragile eggs, which requires this extensive gestation period in the icy depths. Human mothers complain about back pain after just nine months, completely unaware that out in the ocean a prehistoric cartilage monster is spending the equivalent of a bachelor's degree pregnant