marbled rock crab or pachygrapsus marmoratus

marbled rock crab sea pachygrapsus marmoratus cancer atlantic ocean dark violet brown yellow marbling hairy pas semiterrestrial omnivore formations low tide magoito coast carapace coastline fauna one animal wild surface waters habitat marine biology coastal crustaceans outdoors morning summer season eroded landscape geology layers erosion processes sandstone rough limestone strata geological shoreline stony portugal