Mollusks

Nautilus in its natural habitat.

NPS

 

The National Park of American Samoa and the National Marine Sanctuary of American Samoa divers assisted Nautilus researcher Dr. Peter Ward from the University of Washington in a release exercise within the national park, out from the village of Amalau. Researchers are investigating population density andspecies composition surrounding the waters of Tutuila Island.

 

Researcher observes the buoyant Nautilus.

NPS

 

A nautilus is an ancient type of mollusk with a hard, spiraled external shell. Known as a living fossil, the nautilus is found in deep waters about 1,200 feetdown.The nautilus is similar in general form to an octopus (cephalopods), with a prominent head and tentacles. Nautiluses typically have more tentacles than other cephalopods, up to ninety. These tentacles have no suckers,and are undifferentiated and retractable.

It swims by drawing water into and out of its living chamber propels water like a jet propulsion. They do not have a good vision as their eye structure lacks a solid lens. They only have a simple pinhole eye open to its living environment.