All eyes on this amazing amphipod 👀
With a transparent body, the crystal amphipod, Cystisoma magna, is essentially invisible in the dim waters of the ocean’s twilight zone. The lights of our remotely operated vehicles (ROVs) illuminate these curious crustaceans and give us the chance to collect individuals for further study in the lab.
Many midwater organisms have unique visual systems to navigate the ocean’s dark depths. Hyperiid amphipods have a particularly impressive range of diverse eye types, from minuscule eyes in some species that eke out a living in perpetual darkness to quite dramatic eyes in the crystal amphipod and others that experience at least some sunlight.
Cystisoma has a complex visual system, with curtain-like retinas containing special structures called rhabdoms. Rhabdoms are transparent, crystalline receptors found in the compound eyes of arthropods, including crustaceans, insects, and arachnids. Rays of light pass through a transparent cone onto the tip of the rhabdom. This adaptation makes the eyes nearly invisible to potential predators.
