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Photo album:

Cnidarians Galore at the Depths of the Ocean Floor

Cnidarians are a phylum of animals that contain corals, jellyfish, sea anemones, sea pens, and hydrozoans. During the Deep Seamount Biodiversity of Johnston Atoll expedition, a variety of stunning cnidarian species were found. This animal group is divided into two groups polypoid and medusoid. Polypoid cnidarians have tentacles and a mouth that face up and a base that attaches to a substrate or colony of other animals. Medusoid cnidarians have a bell on their top and the tentacles and mouth hang down. Despite their diversity, all cnidarians have stinging cells called cnidocytes, which contain barb-like nematocysts that help in defense and capturing prey. 

The following photos were captured by the ROV Herculesʻ cameras across fifteen dives investigating the geological and biological diversity of the Johnston Atoll Unit of the Pacific Remote Islands Marine National Monument (PRIMNM).

Album created by Science Communication Fellow Onyeweenu Ogene.