Distinguishing the genetic diversity of spotted eagle ray species
It turns out that the spotted eagle ray, once thought to be a single species found around the world, has hidden diversity. Three species are now recognised and Stephen has a hunch that there may even be a fourth in the East Atlantic Ocean. To work out exactly how many species of spotted eagle ray there are, Stephen is collecting DNA from across their distribution to identify different species and understand how populations are connected or fragmented. This information will help create better conservation strategies, protect critical habitats and establish marine protected areas.
Stephen Bergacker
I grew up in a small village in the Belgian countryside, where my love for animals started with our family dog (who, naturally, was the best dog ever). That love grew into a fascination for the natural world, especially after a snorkelling trip to the Caribbean when I was 12. I spent more time underwater than above it during those weeks, and that was the beginning of my passion for marine life.
After completing a Bachelor’s degree in agronomy with a focus on animal behaviour, I headed to the Maldives, where I worked as a coral biologist...
Speciation and genetic fragmentation across global stocks of Spotted Eagle Rays
This project sets out to assess the biodiversity of spotted eagle rays and quantify the level of genetic connectivity among the most widely distributed species.
Spotted eagle rays face threats due to unclear species boundaries and population structures. This pioneering global study uses advanced genetic sequencing to clarify species distinctions and identify critical habitats. The findings will guide conservation strategies, helping to establish marine protected areas and safeguard genetic diversity. This research is vital for the resilience of these threatened rays and to mitigate declines caused by habitat loss and fishing pressure.
Sharks and rays, known as chondrichthyans, are less studied than many other animals, and their true diversity is probably underestimated. Sadly, more than a quarter of these species are considered threatened, and the numbers of oceanic sharks and rays have dropped by 71% in the past 50 years.
Many of these sea creatures are big and can travel long distances across the ocean. Because there are no clear barriers in the open ocean, it was once thought that distant populations were genetically similar. However, just because a species can travel far doesn’t mean its populations are genetically connected. This is especially true for species like the spotted eagle ray that live in both the open ocean and near coastlines.
Spotted eagle rays were once thought to be a single species found worldwide. However, recent genetic studies have revealed several ‘hidden’ species. Currently, three distinct species are recognised: Aetobatus laticeps in the East Pacific, A. narinari in the Atlantic, and A. ocellatus from the Indian Ocean to the Central Pacific. There might even be a fourth species in the East Atlantic, but more genetic data are needed to confirm this. Within these species, especially the widespread A. ocellatus, there is significant genetic diversity that is probably influenced by female rays returning to their birthplace to reproduce.
This project seeks to understand the genetic diversity of spotted eagle rays by studying their DNA from across their distribution. By using advanced genetic techniques, we aim to identify different species and understand how populations are connected or fragmented. This information will help to create better conservation strategies, protect critical habitats and establish marine protected areas. Ultimately, this research will support the survival of these magnificent rays and contribute to healthier ocean ecosystems.
The goal of this project is to determine the actual number of spotted eagle ray species throughout the world.