New publication: The swimbladder does not enhance hearing in the Lusitanian toadfish

New Paper by Daniel Alves Sheds Light on Hearing Mechanisms in the Lusitanian Toadfish.

We’re excited to announce a new publication by Daniel Alves, a PhD student in our lab now nearing the completion of his doctoral work. The article, published in Marine Biology, tackles a fundamental question in Lusitanian toadfish bioacoustics:

📄 Title: The swimbladder does not enhance hearing in the Lusitanian toadfish🧑‍Authors: Daniel Alves, Paulo J. Fonseca, and M. Clara P. Amorim

📚 Marine Biology (2025)

🐟 What’s the research about?

Acoustic communication is vital for many fish species—but how exactly do they hear? While in some species the swimbladder improves hearing sensitivity by transmitting sound vibrations to the inner ear, in others, it plays little or no role.

In this study, it was tested whether the swimbladder contributes to hearing in the Lusitanian toadfish (Halobatrachus didactylus), a highly vocal marine species. Using auditory evoked potentials (AEPs), they measured hearing thresholds in males and females before and after deflating the swimbladder.

Their key finding?👉 No significant difference in hearing sensitivity was found between pre- and post-deflation conditions—strong evidence that the swimbladder does not enhance hearing in this species.

Instead, the Lusitanian toadfish likely relies on particle motion detection via both the inner ear and the lateral line, rather than pressure sensitivity.

This work not only contributes to our understanding of hearing mechanisms in soniferous fishes but also raises interesting questions about how fish detect and process acoustic signals—especially in noisy environments.

👏 Congratulations to Daniel on this important publication on the final stage of his PhD!

Alves, D., Amorim, M.C.P. & Fonseca, P.J. The swimbladder does not enhance hearing in the Lusitanian toadfish. Mar Biol 172, 131 (2025). https://doi.org/10.1007/s00227-025-04693-6