Crustacean · amphipod

Crystal amphipod

Cystisoma sp.

PacificAtlanticIndianSouthernArctic Found in 3 oceans

Depth

From the surface down to about 1,500 m, mostly in the twilight zone

Size

Up to 15 to 18 cm, as big as a hand

Diet

Gelatinous plankton, such as comb jellies

Zone

Twilight zone · 200 – 1,000 m

Key facts

• It is almost entirely transparent, even its gut. In open water, it has nowhere to hide.
• Its giant eyes cover almost its whole head and look upward.
• Tiny round bacteria on its shell limit reflections, like the anti-reflective coating on glasses.
• Its retinas are spread out into thin patches to cast less shadow when seen from below.

Verified sources

1. MBARI : Crystal amphipod
2. Smithsonian Ocean : Giant eyes

In the game: To observe

In the same zone

Müller’s pearlsideMaurolicus muelleri Oceanic lightfishVinciguerria nimbaria Swordtail squidChiroteuthis calyx Odd bobtail squidHeteroteuthis dispar LanternfishFamily Myctophidae HatchetfishArgyropelecus sp.