As they roam the open seas, female argonauts feed on a variety of invertebrates, giving rise to a fascinating interspecies relationship. Writing in MEPS, researchers Thomas Heeger, Uwe Piatkowski, and Heino Möller observed an argonaut with its face partially inside a jellyfish that was secured near the shell mouth with the octopus’s arms. Heeger et al. suggest that such arrangements may provide camouflage, defense, or most incredible, the argonaut might have been feeding directly on food captured by the jellyfish. Juvenile argonauts have also been observed to associate with salps, drifting tunicates that form long chains.
These remarkable creatures are a monument to the beauty and diversity of nature. Unfortunately, given their thin shells, argonauts are especially vulnerable to ocean acidification, which is on the rise.