Tiger Cowrie.
Treasured for its glossy spotted shell, the tiger cowrie polishes its own surface with a fleshy mantle that wraps the shell completely.
Cowries are sea snails famous for their smooth, polished shells. The tiger cowrie is the largest cowrie found in Hawaiian waters and one of the most recognizable, with a creamy shell covered in dark spots that fade and brighten depending on the animal's mood and environment.
The shell stays glossy because the cowrie continuously coats it with its mantle, two flaps of tissue that fold up over the shell when the animal is active. The mantle deposits the same calcium carbonate that builds the shell, repairing wear and preventing algae and barnacles from settling.
Tiger cowries are nocturnal, hiding in reef crevices by day and emerging at night to graze on sponges, algae and small invertebrates. They live for several years and were historically valued throughout the Pacific as currency, jewelry and ceremonial objects.
Like most cowries in Hawaiʻi, populations have declined from heavy collection. Living cowries on the reef should be left in place, where they continue their slow, important work of grazing.
More species in this group.
Day Octopus
A daytime hunter and master shapeshifter, Hawaiʻi's most commonly seen octopus can change color and texture in under a second.
Chambered Nautilus
A living fossil whose ancestors swam alongside dinosaurs, the nautilus drifts through deep reefs in a perfect spiral shell.
Hawaiian Bobtail Squid
A thumb-sized squid that hides in plain sight using bioluminescent bacteria to erase its own shadow under the moon.
Textile Cone Snail
A beautiful but dangerous predator that fires a venomous harpoon to paralyze fish — and whose toxins inspire modern medicine.