Deepy Creepy: Distribution and Ecology of Deep Water Crabs Observed by ROV on the US Eastern Continental Slope and Canyons (and a Case of Mistaken Identity)

Deepwater habitats are home to mega-crustaceans (crabs and lobsters) that serve as both major predators and habitat engineers that structure benthic habitats and transfer carbon between depth zones. Yet little research has been conducted on their abundance or ecology in these habitats. NOAA Ocean Exploration conducted a series of deepwater ROV dives in 2019 to explore canyons and corals along the Southeast (May-June) and Northeast (August-September) regions of the US continental slope. Abundance of crabs was documented along with habitat and other data. Chaceon quinquedens was the most common species present on soft substrata, and typically occurred above 1000 m, where numerous mating pairs were observed. Neolithodes grimaldii was observed rarely, and only at depths >1400 m. Examination of museum specimens suggests that previous reports of N. agassizii in this region were probably due to mis-identification of juvenile N. grimaldii.