Spiky Sea Urchin on Ahyi Seamount

While exploring Ahyi Seamount (an uncharacteristically shallow dive for ROV Hercules), the team spotted this Diadema setosum urchin nestled in an algae bed around 74 meters deep. These marine invertebrates are known for their extremely long, black, hollow spines interspersed with stinging, pincher-like pedicellariae. Look closely at the 10 cm wide test (body) to spot its five characteristic white dots between each radial body segment, which differentiate this species from other long-spined black urchins worldwide. This video reminds us that it takes a team of ocean explorers including pilots, video engineers, scientists, and more to capture the beauty of our global ocean.

The Mattingan: Mariana Arc Volcanic Exploration (NA171) expedition is exploring deep-sea areas identified by the local management and science community, including sites with signatures of active volcanism, abyssal plain habitats, and areas in and around the Monument where new data can support resource management priorities. This expedition is supported by NOAA Ocean Exploration, the Bureau of Ocean Energy Management, and the US Geological Survey via the Ocean Exploration Cooperative Institute.