Introducing a Friend of the Maugean Skate: The Dogfish Shark (Squalus acanthias)

Welcome to our new blog, where we’re excited to introduce a new friend of the endangered Maugean skate and an essential player for our project: the dogfish shark, Squalus acanthias.

Before we dive into why this shark is such a good friend to the skate, let’s take a moment to appreciate the dogfish itself.

Meet the Dogfish Shark

The dogfish shark is one of the most common shark species in the world. For researchers studying shark physiology and endocrinology, this species holds a special place in history. Much of the early foundational research on shark physiology comes from studying the dogfish, as they are relatively easy to catch and keep in captivity for observation.

This species is viviparous, meaning females carry developing embryos inside their bodies until birth. This makes them an excellent species for studying reproductive health.

In Tasmania—or Tassie, as we Aussies like to call it—the dogfish can be found in many areas, including Macquarie Harbour. Over the years, while sampling the Maugean skate population in this region, we also began collecting data on the dogfish. This is where Dr David Moreno, also a member of this team, started investigating the reproductive cycle of the dogfish in Macquarie Harbour.

Dogfish shark Squalus acanthias. Photo © Cynthia Awruch

Troubling Discoveries in Macquarie Harbour

David’s research uncovered some alarming findings: the dogfish population in Macquarie Harbour shows signs of severe reproductive impairment. While females can get pregnant, their embryos often stop developing partway through the pregnancy.

This discovery immediately raised questions. Could the challenges facing the dogfish also be impacting the Maugean skate?

Given how critically endangered the Maugean skate is, invasive studies on this species must be kept to a minimum. That’s where the dogfish shark steps in as an essential ally.

We realised they could act as a surrogate species to help us understand what might be affecting the Maugean skate. The dogfish provides clues about how environmental contaminants might interfere with reproduction in the Maugean skate.

Our findings so far are concerning. Dogfish in Macquarie Harbour exhibit high levels of contaminants known to disrupt reproductive health. These contaminants are particularly concentrated in male sperm, with males generally showing higher contamination levels than females.

PhD student, Maddy Davies-Knight presenting results on contamination in the dogfish at the AMSA conference in Tasmania 2024. Photo © Cynthia Awruch

What’s Next?

Our work with the dogfish is far from over. We are continuing to analyse samples in the lab, refining our techniques, and gathering more data before applying these methods to the Maugean skate.

Recently, we presented this research at AMSA conference (Australia), which was a fantastic opportunity to share our progress and passion for this project. We’re hopeful that what we learn from the dogfish will provide critical insights to protect the Maugean skate.

In summary, the dogfish shark is helping us understand the reproductive health of the Maugean skate, acting as a surrogate species for critical research. By studying this common yet invaluable shark, we’re one step closer to protecting its endangered companion.

Stay tuned for more updates on this exciting journey!

If you also want to hear more about this project, Cynthia gave a presentation for the Museum of Discovery and Science. Watch below:

Team dogfish! Dr David Moreno, Prof Jayson Semmens, PhD student Maddy Davies-Knight and Dr Cynthia Awruch. Photo © Cynthia Awruch