Melissa Cristina Márquez

What if we could estimate a shark’s age from a small blood sample rather than counting growth rings in its vertebrae? New research on zebra sharks has developed an “epigenetic clock” that can predict age with surprising accuracy, using changes in DNA methylation at just 10 sites. The approach could eventually give conservation scientists a non-lethal way to understand the age structure of wild shark populations, while also offering clues about how aging itself evolved across vertebrates.

The deep sea has a habit of keeping secrets.

The Adriatic Sea is one of the Mediterranean's most important regions for sharks and rays, yet many of its species are critically endangered. New research based on decades of monitoring and close partnerships with local fishers is revealing previously unknown habitats, rediscovering rare species, and reshaping what scientists thought they knew about these animals.

What if the sharks we see on a reef today are only a fraction of what that ecosystem once supported?

Whale sharks have unique spot patterns, like fingerprints. In the Maldives, these help researchers track their movements, growth, injuries and return visits.

Milo the whale shark has now been tracked across more than 34,000 miles, setting a record for the longest movement record ever documented for a shark. Retagged five times over nearly a decade, his travels reveal just how enormous and flexible a whale shark’s world can be.

The finding challenges long-held assumptions that freshwater elasmobranchs stay close to home and suggests conservation efforts may need to protect entire river systems.

What if a species we thought stretched across thousands of miles of Pacific coastline actually lives in only a fraction of that range? A new look at the Pacific guitarfish suggests exactly that.

Scientists have used underwater ultrasound to confirm pregnancies in three wild oceanic manta rays in Mexico, including one whose pregnancy showed no obvious external signs.

A 5-foot-long whale shark found in Indonesia may have given scientists one of their best clues yet about where these enormous fish spend the earliest weeks of life. The discovery in Saleh Bay, combine...