Big fish research

Myoung Hoon Ha is undertaking a PhD in fish sensory systems

Big fish have been a source of fascination for PhD candidate Myoung Hoon Ha since he was young.

“Studying big pelagic fish like tuna and billfishes has been a dream of mine since I was a little

kid. Initially, I was uncertain about what field of science I should choose to further study these fascinating beasts.”

After doing a sensory biology and neuroscience course, Hoon decided to pursue further studies in fish sensory systems.

“Every behaviour, from a simple motion of a tail to transoceanic migration, is mediated via environmental cues including light, smell, and sound. Understanding fish sensory

systems helps us to assess the human impact on fish behaviour from individuals to whole populations,” he explains.

Hoon, who is currently studying the sensory systems of southern bluefish tuna, says his field of study is specialised, which made it important to find the right university and supervisor.

“I have followed the work of Professor Shaun Collin for some time. He is one of the top researchers in this field, and so I ultimately decided to do my PhD under his supervision.”

Hoon says the highlight of his research so far has been capturing an image of bluefin tuna inner ear hair cells, something that took a painstaking 20 months.

“Hair cells react to sound motion and play a crucial role in the way fish hear. Looking for tiny hair cells in a large, preserved tuna is like finding ancient treasure. You have to navigate through multiple layers, where one tiny mistake can ruin the whole preparation!”

When he obtains his PhD, Hoon hopes to continue researching sensory systems of large pelagic fishes.

“Although bluefin tuna are my primary focus, swordfish are my El Dorado among the pelagic fishes, a species I would like to concentrate on when I graduate”.