Discovery of a mud‐covering cephalopod evidences the complex life habits in the abyss

Cephalopods, including octopuses and squids, are a conspicuous component of marine ecosystems, present across all ocean depths (Jereb & Roper, 2010). At least 42 of the 50 described cephalopod families occur in the deep ocean, including the charismatic giant (Architeuthis spp.) and colossal squids (Mesonychoteuthis hamiltoni) in the midwater and cirrate octopods in the benthic boundary layer (Hoving et al., 2014). However, little is known about the distribution, diversity, and life habits of deep-sea cephalopods, especially on abyssal plains (3000–6000 m depth), among the least studied features of our planet despite comprising over half its surface area. The seemingly low species abundance there, combined with avoidance behaviors, makes abyssal cephalopods elusive and difficult to study. In March 2023, at 4100 m depth, we captured unexpected mud-covering behavior of an undescribed species of whiplash squid (Figure 1) within the Clarion-Clipperton Zone (CCZ), an area in the abyssal central Pacific targeted for seabed mining. The squid was partially covered in mud with vertically exposed, rigid tentacles appearing to imitate biogenic stalks. This finding adds to the evidence of complex life habits in abyssal cephalopods (Golikov et al., 2023; Purser et al., 2016) and suggests seafloor sedimentary structure should be considered in understanding their distribution.