Timelapse footage of a wall of migrating jellyfish in Jellyfish Lake in Palau, Micronesia. These jellyfish Mastigias cf. papua etpisoni in Jellyfish Lake have been isolated from their ocean relatives for some 12,000 years, and have developed a symbiotic relationship with photosynthetic algae that live in their tissues. To maximise the productivity of their algae, the jellyfish follow the sun on a daily cycle, swimming towards the eastern end of the lake at first light, then westwards as the sun moves through the sky. The jellyfish avoid the shade at the edges of the lake, forming a wall of jellyfish there. Footage sped up by eight times.