Authors

Akito Ogawa, Chong Chen, Julia D Sigwart

A newly discovered sea cucumber species, Acanthotrochus verruciosseous sp. nov., has been described from more than 5,200 meters deep in the Aleutian Trench of the North Pacific, making it one of the deepest records for its genus. This rarely seen holothurian is clearly distinct from its closest relatives, with uniquely knobby wheel-shaped skeletal structures that have never been observed in other Acanthotrochus species. Previously known only from the North Atlantic, Indian Ocean, and Antarctica (and from much shallower depths) this discovery marks the first record of the genus in the North Pacific and extends its known depth range into the lower abyssal zone. Genetic evidence from mitochondrial DNA further confirms that this is a species new to science. This finding highlights how much of Earth’s deep ocean biodiversity remains unexplored, and how extreme environments continue to reshape what we know about life in the sea.

(Scanning electron micrograph of a wheel ossicle of  Acanthotrochus verruciosseous courtesy of Akito Ogawa)