### Identification At just 3–5mm—barely the size of a grain of rice—the Hairy Shrimp is the ocean’s ultimate master of disguise. Its body is densely cloaked in hair-like filaments called setae, which break up its silhouette until it is indistinguishable from a stray clump of algae or debris. To spot one, look for a tiny "clump" that seems to have a mind of its own. Unlike the larger Algae Shrimp, *P. simulans* has a distinctively short, notched rostrum and a hunched posture. Their coloration is highly variable; they can be emerald green, rusty brown, or even a ghostly translucent white, typically matching the exact hue of their surroundings.
### Habitat & Range This species is a prized find for "muck divers" across the Indo-West Pacific, from the Philippines and Indonesia to the southern islands of Japan. They favor shallow, sheltered coastal waters, typically inhabiting sandy slopes or rubble zones. You’ll most likely find them clinging to patches of algae, seagrass, or hydroids in lagoons where the current is gentle.
### Behaviour Observation requires a keen eye and a steady lens. *P. simulans* does not swim in straight lines; instead, it employs a rhythmic, jerky "bobbing" motion. This "drunken" drift perfectly mimics the natural surge of the ocean, making the shrimp look like a piece of dead seaweed tumbling in the current. They are solitary creatures, spending hours motionless until disturbed, at which point they perform a short, frantic hop before vanishing back into the substrate.
### Diet These minuscule crustaceans are primarily detritivores. They use their microscopic claws to pick through the "turf" of their algal homes, scavenging for organic particles and tiny microorganisms trapped within the filaments.
### Fascinating Fact The Hairy Shrimp is a slow-motion chameleon! They have the incredible ability to change their base color over the course of several molts to perfectly match the specific species of algae they inhabit, ensuring they remain virtually invisible to hungry damselfish.