The Rising of the Palolo

The palolo (Eunice viridis) is a segmented saltwater reef worm that lives below the low tide level in the crevices of shallow coral reefs. The worms seldom leave their burrows and are active mostly at night. Once or twice a year, however, great masses of the worms swarm to the ocean's surface to spawn as part of a predictable life cycle.

The palolo itself consists of two parts, a worm-like forward portion up to 10 centimeters long with eyes and a mouth, and a narrower 20-centimeter rear portion which is used for reproduction. The rear part is blue-green in the female and reddish in the male, and has a light-sensative eyespot. When the moment to spawn arrives one night, the palolos back out of their burrows and detach their rear portions. The front parts squirm back into the reef to begin growing new appendages for the next season, while the male and female tails swarm to the surface, writhing together until dawn when they burst, releasing the eggs and sperm. The fertilized eggs become larvae that drift along until they find a place in the coral to colonize.

The numberless worms must rise simultaneously for fertilization to take place, and this mass spawning always occurs on the last quarter moon in late spring, which in Samoa is seven days after full moon in late October or early November. Swarming can occur on two or three successive nights, with the second night being the most important. A brown foamy slick on the ocean surface and a strong salty smell, usually caused by a mass spawning of corals, often signals that the palolo will spawn two days later.

This event takes place in spring because at that time the larvae have their best chance of survival. Many species of fish and shellfish have adapted their lifestyles to that of the palolo, spawning around the same time so the palolo larvae will be available as a food source for their own offspring.

Although the palolo is common throughout the South Pacific, it doesn't swarm everywhere. The phenomena is best known in Samoa and Fiji, although it also occurs in Tonga and parts of Melanesia. The islanders have long considered palolo a delicacy to be eaten raw or fried, and it has an extremely rich taste and is high in protein. Thus each year on the assigned night, locals will be waiting with hand nets to scoop up in large numbers this caviar of the Pacific.

In Samoa, the people traditionally adorn themselves in the fragrant yellow blossoms of the moso'oi flower for the occasion. If you happen to be in Samoa or Fiji in October or early November, it's certainly worth asking when the rising of the palolo will occur. Sadly though, environmental degradation and overharvesting have taken their toll, and you must get away from major population centers to witness the spectacle at its best.