Gillyweed – Drowning with Gills?

Rowan Reynolds, Chris Ringrose


In David Yates’ film adaptation of J. K. Rowling’s Harry Potter and the Goblet of Fire, Harry Potter passes the second Triwizard task by consuming Gillyweed. This Mediterranean plant allows him to breathe underwater by growing gills on his neck. The gills were approximated to be 60 cm2 in surface area, and using standard measurements for a boy of his age, Harry was estimated to need to process 443 litres of water per minute. This came to mean the water would have to flow at 2.46 m s-1 across his gills, far faster than he could inhale and exhale.


Book; Film; Biology; Respiratory issues; Harry Potter

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