aquatic beach Busycon carica coast dextral gastropod gastropod shell knobbed whelk marine marine gastropod molluscs migratory mollusk mollusks ocean sand sea Sea snail sea snails sea-snail seasnail shell Shell on the beach shore splash water wave welk whelk accident barren industrial oil oil spill oil tanker pollute pollution spill spillage auger shell auger snails corals India krayker mantle marine gastropod mollusks mollusc Mollusca Molluscs sand-dwelling carnivores seashell shells sun and sea Terebridae venomous barb augur shells Incredible India pebble pebbles seashells stone herbivore land slug snail creature cuttlefish fish octapus sealife Squid aquarium conical freshwater limpet limpets nature patella saavem shape snails vulgata