During Dive 05 of the 2021 North Atlantic Stepping Stones, we encountered this worm in the genus Swima — a rather descriptive name given that we saw it swimming in the water column! Members of the onshore science team identified the worm as potentially a green bomber worm (Swima bombiviridis), so named because it has sacs of bioluminescent fluid from which, when disturbed, it can release a glowing green “bomb.” This burst of light distracts potential predators so that the worm can escape.
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The Green Bomber