This little octopus is a master of survival in the deep sea.

The midwater octopus (Japetella diaphana) is one of just a handful of octopuses that live in open water. This species calls the expansive waters of the ocean’s twilight zone home. Here, there are no rocks or reefs for hiding or nesting. Instead, Japetella has evolved creative solutions to survive life’s everyday challenges.

Japetella cannot rest on the seafloor. A buoyant gelatinous body means this octopus can drift with the currents, and a low metabolism helps conserve energy while swimming.

A nearly transparent appearance helps Japetella blend into the dim, twilight waters. When the octopus sees the glow from a bioluminescent predator or senses movement nearby, a built-in defense mechanism gets to work. A network of tiny pigment-filled cells called chromatophores covers the octopus’s entire body. By rapidly expanding these cells, Japetella can shift from crystal clear to opaque orange. Since red and orange light do not reach the deep sea, this color change helps Japetella remain hidden from predators, an impressively nimble camouflage response to threats.

Life out in the open presents other challenges for Japetella too.

A mother midwater octopus does not attach her eggs to the seafloor. Instead, she carries them in her arms. To protect herself and her offspring, she descends to the deeper waters of the midnight zone, where there are fewer predators. Like other octopus moms, she makes the ultimate sacrifice to ensure the next generation’s survival. A mother Japetella lives just long enough for her babies to hatch and begin their journey back up to twilight waters.

Threats like climate change and pollution present new challenges for deep-sea animals.

The depth range of the midwater octopus overlaps with the oxygen minimum zone, a naturally occurring layer of low-oxygen water. Climate change is warming our ocean. Warmer surface waters do not easily mix with cooler waters, reducing replenishment of oxygen-rich waters. Scientists predict the oxygen minimum zone will expand with climate change. Japetella already live at the edge of their oxygen tolerance—will climate change push them over the edge?

MBARI’s advanced technology has provided vital insight into the secret lives of deep-sea animals. Our work will help us understand how Japetella and other denizens of the deep will navigate a changing ocean.