Xenophora pallidula (Reeve, 1842) - carrier snail shell, apical view (12.7 cm across), Philippines, modern (latest Holocene). Numerous attached shells are present. Most of the objects that have been picked up by this individual are snail shells, but there are also a few clam shells, and a long worm tube.

The xenophorid snails (a.k.a. carrier snails), especially members of the genus Xenophora, are remarkable in their tendency to pick up other shells, skeletal fragments, rock fragments, or corals (sometimes still alive) from their surrounding environment and cement these objects to their own shells. The result looks like a pile of shells on the seafloor. Often, sponges and serpulid worm tubes are found encrusting the xenophorid shell - they contribute to the illusion that a xenophorid is simply a patch of seafloor. Xenophora carrier shell snails do this as a camouflage defense against predators. Decorator crabs are arthropods that do this as well (storage.montereybayaquarium.org/storage/animals/520x260/d...).

Xenophorids are principally detritivores on unconsolidated, fine-grained to coarse-grained to rubble-bottom substrates.

Classification: Animalia, Mollusca, Gastropoda, Mesogastropoda, Xenophoroidea, Xenophoridae

The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most gastropods have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.