Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
A koi fish, named "Hanako", was owned by several individuals over many years and lived to be 226 years old, dying in 1977.
6
There is a disease called ichthyosis that turns the skin scaly like a fish.
90
Urechis unicinctus is a species of marine spoon worm that is widely referred to as the ‘penis fish’.
2
The seahorse is the only fish to have a neck.
12