The mantis shrimp attacks with a club-like appendage that accelerates about as fast as a bullet, fast enough to make the surrounding water flash into cavitation bubbles — and its eyes carry up to 16 types of color photoreceptors, compared with 3 in humans. Surprisingly, studies show its actual color discrimination is coarse: it trades fine color detail for a much faster scanning system.
The mantis shrimp stores energy in a spring-like structure in its arm, then releases it in a strike that moves faster than the water can get out of the way. That speed leaves a low-pressure pocket behind the club — a cavitation bubble. When the bubble collapses a moment later, it releases a burst of energy, so prey effectively gets hit twice: once by the club, and once by the collapsing bubble. The system is strong enough to crack shells, and larger species have even been known to damage aquarium glass.
With up to 16 photoreceptor types, it would be natural to assume the shrimp sees a rainbow far richer than ours in fine detail. Experiments from the University of Queensland found something stranger: when the animals were trained to distinguish colors for a food reward, they struggled with shades that humans tell apart easily.
The researchers' explanation is that the shrimp's brain does not build color the way ours does. Instead of comparing signals to work out fine gradations, it appears to scan its eyes across a scene and read which receptors fire in which order — a fast pattern-recognition shortcut. Less precision, but an answer almost instantly, which suits an ambush hunter that has to decide in a split second whether something is food, mate, or threat.
See the 20-second version: "The Shrimp That Punches Like a Bullet — Things You Didn't Know" on LOE PRESSURE (TikTok @loepressure and YouTube @LoePressure).
▶ Watch on TikTok→ What Is Brain Freeze, Really?
→ Can Hot Water Freeze Faster Than Cold Water?
Fascinating facts you didn't know. Come learn with me — no pressure.
Sources: Smithsonian Ocean Portal (mantis shrimp strike and vision); University of Queensland research — Thoen et al., Science (2014), on mantis shrimp color processing.