Nautiluses are cephalopods—a kind of mollusk. Cephalopod means "headfoot" which reflects their relatively complex brain and the numerous tentacles. Nautiluses are related to squids and octopuses, but are easily differentiated by their distinctive, ornate, coiled shells. 

Although their taxonomy is poorly resolved, the nautilus family, Nautilidae, is currently considered to include seven species in two genera, Nautilus and Allonautilus, all which share the common name, chambered nautilus. 

The chambered nautilus, Nautilus pompilius, is a highly vulnerable species because of its life history characteristics, including low reproductive rates, slow growth, and late maturity. This species is thought to occur in small, isolated populations throughout its range. They are also limited by both depth and temperature tolerances. They have multiple predators, including sharks, bony fishes, and octopuses.

Chambered nautiluses are primarily targeted for their shells, which are sold commercially and traded internationally for use in art, furniture, jewelry, and other items. 

In 2018, NOAA Fisheries listed the chambered nautilus as a threatened species under the Endangered Species Act.

The soft-bodied nautilus lives inside a hard, chambered shell. It uses the chambers to pump air and water in and out of its shell, creating jet propulsion to thrust itself backwards and to make turns. 

They possess a siphon tube, known as a hyponome, which runs the length of the shell. The hyponome allows the nautilus to control its buoyancy by regulating air and water in the shell chambers.

Nautiluses are hunters and pick up food scents in the water column with chemosensors on their tentacles. They consume animals such as fish, crabs, and lobsters with their sharp, beak-like mouth.

In 2016, the Center for Biological Diversity petitioned NOAA (PDF, 58 pages) to list one species of chambered nautilus, Nautilus pompilius, as a endangered or threatened species under the ESA. 

NOAA Fisheries reviewed the petition and determined that a status review for the species should be conducted. 

In October 2017, NOAA Fisheries completed a status review of this species and proposed to list it as threatened under the ESA. Read the ESA status review report.

On September 28, 2018, NOAA Fisheries published a final rule to list the chambered nautilus as threatened under the ESA.

The chambered nautilus, Nautilus pompilius, is listed as threatened under the Endangered Species Act. 

In addition, all chambered nautiluses are vulnerable to international trade and are listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. All seven species, in two genera Nautilus and Allonautilus, are listed under CITES.

At the 2016 meeting of the Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora, the Parties agreed to include the entire nautilus family of chambered nautilus in Appendix II of CITES. The United States—joined by Fiji, India, and Palau—submitted the proposal for consideration (PDF, 31 pages) at the meeting.

A global treaty, CITES protects species from becoming endangered or extinct because of international trade. The inclusion of the family Nautilidea in CITES Appendix II will help ensure that the international trade in these species is legal and sustainable. 

The U.S. Fish and Wildlife Service is the government agency designated under the Endangered Species Act to carry out the provisions of CITES. NOAA Fisheries provides guidance and scientific support on marine issues given our technical expertise. Learn more about U.S. FWS efforts under CITES for the chambered nautilus.

NOAA's Role in Nautilus Research

NOAA Fisheries has collaborated for several years with other countries and researchers to study the distribution and biology of these iconic species. NOAA Fisheries has also helped fund studies about the extent and impact of international trade on these species. TRAFFIC and the World Wildlife Fund published a 2016 study that investigated the trade of chambered nautilus in the range countries of Indonesia and the Philippines and in major consumer markets to determine if trade is a threat to this species. The study called for better monitoring of the international nautilus trade. Read the report: An Investigation into the Trade of Nautilus (PDF, 113 pages). 

A 2014 study compared nautilus populations in the Philippines, Australia, Fiji, and American Samoa and explored the potential impact of fishing on population abundance. Read the report: Comparative Population Assessments of Nautilus sp. in the Philippines, Australia, Fiji, and American Samoa Using Baited Remote Underwater Video Systems.

NOAA Fisheries and the U.S. Fish and Wildlife Service also held a workshop in June 2014 that brought together experts in the study of chambered nautiluses to share and discuss the available biological information and trade data. Read the report: Chambered Nautilus Experts Workshop Report Summary (PDF, 307KB). 

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An international research team traveled to the Indo-Pacific to explore the deep ocean in search of nautiluses, one of the most ancient living creatures on Earth. Watch some of the footage that was captured.