A Fish That Looks Like a Rock -- Fourspine Sculpin, Japan

The fourspine sculpin live in the Koza river, one of the clearest rivers in Japan. Master of disguise, these fish camouflage as rocks to capture prey by ambush. There is also an interesting saying about this species: "they catch sweetfish with the spines on their gill cover." This episode features the hunting skills of these river bed ninjas.

Note: This is part of a 13-episode series.