Feather Duster Worm.
A tube-dwelling worm that unfurls a spectacular feathery crown to filter plankton — and snaps it back into hiding in a fraction of a second.
Despite their delicate, flower-like appearance, feather duster worms are true segmented worms — relatives of earthworms and leeches. The animal lives inside a leathery tube cemented to the reef and extends a fan of feathery, pinnate gills (the radioles) into the current to catch plankton and breathe.
Touch the water near one and the entire crown vanishes in a fraction of a second. A specialized giant nerve fiber runs the length of the body, allowing a single signal to retract the gills almost instantly when a shadow passes or a fish noses too close.
If a predator manages to bite off the crown, the worm can grow a new one within weeks. Hawaiian reefs host several species, including delicate banded forms in cracks and the larger, brilliantly colored Christmas tree worms that perch on top of live coral heads.
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.