The golden jellyfish of Ongeim'l Tketau hosts symbiotic dinoflagellates, and photosynthesis by those algae supplies much of the animal's energy. The daily migration puts the medusae where the light is: they move towards the eastern basin at sunrise, reverse in the afternoon, and reach the western side by late day, a horizontal transit of hundreds of metres.
The track has a second consequence. The jellyfish stop short of the shaded shoreline margins, where predatory anemones live among mangrove roots. Halting at the shadow line keeps them clear of that edge, so the light cue serves both feeding and avoidance.
There is also a vertical component: the medusae descend at night into deeper water, though the lake's lower layer is anoxic and rich in hydrogen sulfide, which sets a hard floor. The population is not static. It collapsed to undetectable levels during the 1998-1999 El Nino, recovered, and fell again during a drought around 2016 before recovering once more, which makes it a well-observed case of a jellyfish population responding sharply to climate variability.