Captain Argo

Jan 2024, Anilao, Philippines

In the open ocean at night, billions of small creatures drift through the infinite darkness. During a blackwater dive in Anilao Philippines, I stumbled upon a unique species of shelled octopus from the genus Argonauta, no larger than a thumbnail, hitchhiking on a chain of salps—a colonial group of gelatinous, barrel-shaped planktonic tunicates.

Within the translucent chamber formed by the salp's gelatinous covering, each individual harbors an intriguing orange ball-like structure, serving as a digestive organ for filter feeding. By changing its chromatophores (pigment cells), the octopus seamlessly matched with the coloration of the salp's digestive organ, transforming into an invisible passenger aboard a luxurious spaceship.

You are witnessing the most striking example of camouflage in the nature. Unlike the inhabitants of coastal reef ecosystems, which find refuge in the intricate three-dimensional architecture of their surroundings, plankton have no shelter in the vastness of the open ocean. Instead, they become the very environment they inhabit—moving castles adrift in the sea.

In this case, the octopus has ingeniously found a spot aboard the salp spaceship. Known for their remarkable ability to mimic their surroundings, octopuses typically blend into rocks, reefs, or other creatures. However, here, this clever cephalopod assumes the guise of another organism's organ, maintaining an innocent look while subtly tilting its body as if to steer the spaceship into the depths.