Fiji Balolo Rising

Twice a year, on a trigger set by the moon, the reefs of Fiji perform one of the ocean's most exact mass spawnings.

The balolo, a marine worm (Palola viridis, long known as Eunice viridis), spends its life hidden in crevices of the coral reef.

Then, on a single appointed night, it does something extraordinary: each worm detaches the rear, reproductive half of its own body, packed with eggs or sperm, and sends that writhing, faintly glowing tail wriggling to the surface — while the head stays safely below to regenerate.

Millions rise together in the hours before dawn, turning patches of sea into a soup of squirming green and reddish-brown strands.

The timing is famously reliable: the rising comes one night each in October and November, on the eighth night after the full moon, just before first light.

It is a beloved village event — families paddle out by canoe with nets and buckets to harvest the protein-rich tails, prized as a delicacy and folded into Fiji's calendar and culture as the 'Fijian whitebait' season.

Where to see it

A taste of where to see it. The full map, exact coordinates and the best timing for each spot live in the app.