animal crab hermit little sand shell small animals aquatic closeup coast creature Crustacean exoskeleton Hermit Crab hide macro marine scavengers sea snail shell shore social aquarium claws crabs decorative Incredible India krayker mantle mollusc Mollusca Molluscs mother of pearl nature ornamental pebble undersea beach sand pebble aquatic life blue conch corals India Mollusc shell mollusks pointed pointy sands sea sea life sea shells Sea snail seashell sky snail spiral shell coiled design ornament protective sharp spike