Rare Species Found in Your National Marine Sanctuaries and Monuments

America’s national marine sanctuaries and monuments protect some of the ocean’s rarest and most fascinating creatures—species that have evolved in unique ways to thrive in these underwater habitats. From deep-sea black corals older than the pyramids, to the elusive and strikingly beautiful masked angelfish (Genicanthus personatus), found only in remote, deep reefs of Hawaii. These marine wonders highlight the importance of conservation efforts that keep our ocean and Great Lakes waters healthy. Here are 11 rare and endemic species that call these protected waters home–either for their entire lives, or for part of their lives—each with its own incredible story.

1. Nautilus (Nautilus samoaensis) – National Marine Sanctuary of American Samoa

The Nautilus samoaensis, a newly identified species of nautilus, was officially described in 2023 and is native to the waters of American Samoa. This ancient mollusk is a distant relative of octopuses and squid. Unlike its cephalopod cousins, the nautilus boasts a remarkable external shell, spiraled and hard, and can have up to 90 tentacles—far more than the eight of an octopus. Found in deep waters around 1,200 feet below the surface, it lives in the remote regions of National Marine Sanctuary of American Samoa. In recent years, researchers from the sanctuary and the National Park of American Samoa, in collaboration with Dr. Peter Ward and Dr. Gregory Barord, have been studying the species’ population and distribution. Their efforts include tracking the nautilus’ movements with a release exercise off the coast of Amalau village to better understand its role in the ecosystem surrounding Tutuila Island.

Nautilus samoaensis is considered rare, though specific population data is limited since it was only just discovered in 2023. Researchers suspect that the Nautilus samoaensis is experiencing similar challenges as other nautilus species, which have seen declining numbers in certain parts of the Pacific due to human activity.