This unique shrimp uses buoyancy to conserve energy in the deep sea

MBARI’s advanced underwater robots have filmed thousands of hours of deep-sea video. The team in MBARI’s Video Lab combs through this trove of footage to identify and label the animals and objects we observe as our scientists and engineers conduct their research. The team has gone deep into the vault to find some of their favorite moments in MBARI’s history of ocean exploration.

This unique shrimp, Physetocaris microphthalma, has a dazzling array of adaptations for life in the midwater, an endless expanse of open water deep beneath the ocean’s surface and far above the bottom. With no rocks or reefs to rest on, Physetocaris uses buoyancy to conserve energy. Their inflated carapace (hard outer coating), prominent rostrum (beak-like projection on their head), and extraordinarily long antennae help them stay adrift. Life out in the open means Physetocaris has to hide in plain sight. A transparent body with splashes of red is clever camouflage—red wavelengths disappear in these black waters, leaving this shrimp nearly invisible to predators.

Sightings of Physetocaris are exceedingly uncommon. MBARI researchers have spotted this shrimp just four times in nearly four decades of ocean exploration. While rarely encountered, this species has been reported from locations around the world. We have a lot to learn about the animals that live in the ocean’s inky depths. Each observation, however rare, helps us expand our understanding of the largest living space on Earth.

Dive in to learn about other amazing animals of the deep: https://www.mbari.org/education/anima...


Editor: Kyra Schlining
Production team: Larissa Lemon, Nancy Jacobsen Stout, Susan von Thun, Kristine Walz
Music: saturn-electronic-ambient (Pond5 055376075)

Reference:
P.A. Peres and H.B. Bracken-Grissom (2023). Rare yet everywhere: phylogenetic position of the enigmatic deep-sea shrimp Physetocaris microphthalma Chace, 1940 (Decapoda, Caridea). Invertebrate Systematics, 37(8): 529–537. https://doi.org/10.1071/IS23024