### Identification The Acadian Hermit Crab (*Pagurus acadianus*) is the robust "heavyweight" of the North Atlantic tide pools. Growing up to 1.2 inches in carapace length, its most striking feature is its coloration: a rich, reddish-brown or orange-tan. To identify it with certainty, look closely at the large right claw (cheliped). You will see a distinct, broad, dark orange or reddish stripe running right down the center. This "racing stripe" is your primary field mark, distinguishing it from the similar Hairy Hermit (*P. arcuatus*), which lacks the stripe and possesses much bristlier legs. Their eyes are set on long stalks with teardrop-shaped corneas, giving them a curious, alert expression.
### Habitat & Range This species is a cold-water specialist, ranging from the icy waters of Newfoundland down to the Chesapeake Bay. While younger individuals frequent deep, rocky tide pools, adults are primarily subtidal, venturing down to depths of nearly 1,600 feet. Look for them in areas with sandy or gravelly bottoms where large gastropod shells are plentiful.
### Behaviour Observing an Acadian Hermit is like watching a frantic real estate mogul. They are highly active and aggressive about "housing," frequently engaging in "shell rapping" where they bang their shell against a rival's to force an eviction. They prefer the spacious, sturdy shells of Northern Moon Snails (*Lunatia heros*) or Whelks. In the field, you’ll notice they are surprisingly fast; when startled, they retreat with a sharp *click* into their shell, blocking the entrance with that massive right claw.
### Diet As the ultimate beachcomber, this crab is an omnivorous scavenger. Using its smaller left claw like a delicate fork, it picks apart detritus, carrion, and algae. It also uses its feathery mouthparts to filter-feed organic particles from the passing current.
### Fascinating Fact The Acadian Hermit Crab often hosts a "living rug" on its shell! It frequently shares its home with Snail Fur (*Hydractinia echinata*), a colony of tiny pinkish polyps. This isn't just decoration; the polyps provide camouflage and a stinging defense against predators, while the crab provides the polyps with a mobile feast of leftovers.