A rare Arctic record of Haliphron atlanticus (seven-arm octopus) from Bodø, Norway

Haliphron atlanticus Steenstrup, 1861, the seven-arm octopus, is a large deep-sea octopod with circumglobal distribution, yet it remains poorly documented due to its inaccessible mesopelagic to benthopelagic habitat and elusiveness. Here we report a rare observation, based on disarticulated remains recovered from a stranding event in Bodø, Arctic Norway (67.27°N, 14.43°E) in March 2026, following an initial report by local citizens. The specimen was identified as an adult female based on morphological examination of recovered remains, including arms, egg clusters, distal oviduct, and both jaws of the beak. Molecular identification based on COI barcoding confirmed species identity, with 100% sequence similarity to two North Atlantic reference sequences. Phylogenetic analysis placed the Bodø specimen unambiguously within the North Atlantic lineage, with zero divergence from specimens from the USA and northwest Spain and a 0.0254 divergence from the North Pacific lineage. These sequences represent the first COI data from an Arctic specimen for this species, filling a geographic gap in the molecular reference database and contributing to the growing evidence supporting the existence of at least two lineages within H. atlanticus .