Swimmer's ear is the colloquial name for acute otitis externa, an infection of the outer ear. Though the nickname implies that you get the infection from swimming, you can contract swimmer's ear ...

The outer ear is the part of the ear we can see ... The possible causes are cancers extending from the ear flap. Or cancers from the parotid gland or lymph nodes around the ear can spread to the ...

So, unlike humans and our big ear flaps (that came from gills ... are funnel-shaped openings that lead to the ear canal, and outer, middle, and inner ear. A similar set up to humans, really ...