Seahorses' claim to fame in the animal kingdom has been that the male has the unique ability to give birth. But when it comes to the pregnancies, it turns out they have more in common with humans than experts previously thought. A study published Tuesday in the journal Molecular Biology and Evolution has answered questions about the seahorse gestation period that have largely remained a mystery. 

Researchers from the University of Sydney have found that male seahorses do more than carry the babies -- playing a major role in providing nutriment to their embryos, much like human mothers. 

"Surprisingly, seahorse dads do a lot of the same things human moms do," said Dr. Camilla Whittington, a professor at the university's School of Biological Sciences.

The research revealed that male seahorses are able to deliver nutrients to the embryos, particularly energy-rich lipids, and calcium, which enables the development of the embryo's skeleton. Researchers believe that it is likely that the nutrients are secreted in the male's brood pouch and then absorbed by embryos.

"Seahorse babies get a lot of nutrients via the egg yolk provided by their mothers, but the pouch of the fathers has also evolved to meet the complex challenges of providing additional nutrients and immunological protection, and ensuring gas exchange and waste removal," Whittington said.

Male seahorses' gene expression during the pregnancy also parallels that of humans, the study found. Researchers looked at samples from the male's brood pouches in what was the first gene sequencing study of its kind to determine how genes changed throughout seahorse gestation.

"Regardless of your species, pregnancy presents a number of complex challenges, like ensuring you can provide oxygen and nutrients to your embryos," Whittington said. "We have evolved independently to meet these challenges, but our research suggests that even distantly related animals use similar genes to manage pregnancy and produce healthy offspring."