Melissa Cristina Márquez

A new study has identified 122 Important Shark and Ray Areas (ISRAs) across Asia, spanning 1 million km² but representing only 3% of the region's waters. These critical habitats support 121 Chondrichthyan species, with nearly 76% already threatened. Despite being based on extensive data, only 5.4% of ISRAs overlap with marine protected areas, leaving most vulnerable to fishing pressure. Conservation efforts are hampered by data gaps, often biased towards charismatic species, and a lack of political will and funding. Effective protection requires international cooperation, as these species cross borders. The ISRA map provides a crucial roadmap, but translating this scientific knowledge into meaningful action is vital to prevent further extinctions.

A new study utilizing historic museum specimens has revealed a drastic decline in the genetic diversity of critically endangered largetooth sawfish. Researchers extracted DNA from 375 sawfish rostra dating back to the 1800s, comparing it with modern samples. The findings show a sobering picture: globally, genetic diversity has plummeted, with only 6 of 35 historical genetic variants remaining. This loss significantly impacts the species' ability to adapt to future environmental changes. While Australia offers a rare success story due to early protections, other populations, like Brazil's, are now critical conservation priorities. The study highlights the invaluable role of museum collections as "DNA time machines" and emphasizes that preserving genetic diversity, not just population numbers, is essential for long-term species resilience. Recognizing distinct evolutionary lineages is key for targeted conservation efforts.

Venezuelan fishers in 2014 discovered unusual eagle ray dental plates, later identified as belonging to the genus *Aetomylaeus*. This genus was previously unknown in the Western Atlantic, challenging established biogeographical patterns. Scientists propose three hypotheses: an undiscovered relict population, long-distance vagrancy from the Eastern Atlantic, or hybridization between local ray species. This finding underscores significant gaps in marine biodiversity knowledge and the limitations of current sampling methods. It also highlights potential undetected populations or lineages, impacting conservation efforts for often threatened or data-deficient ray species. The discovery raises crucial questions about marine dispersal and evolution.

As a fishing net was hauled from the waters of Galicia's Ría de Pontevedra on a December morning, an unexpected silhouette appeared among the catch.

There is a presence to tiger sharks. It's not just their often imposing figure, as they tend to be quite big sharks when one is seen for the first time by the general public.

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.