eub | epitoky

http://depts.washington.edu/fhl/zoo432/plankton/plannelida/pl_annelida.htm

Epitokes are benthic worms, or parts of worms, that swim to the surface and release eggs or sperm. In one family of polychaetes, the syllids, the posterior (rear) portion of the worms is modified to carry either eggs or sperm. This epitoke eventually breaks off from the main part of the worm, and swims to the surface to reproduce. After the eggs are fertilized, female epitokes brood the embryos in sacs on their stomachs until they hatch (see photo on left, below). The remaining benthic worm is called an atoke, and will continue to feed and grow, eventually producing new epitokes. Syllid epitokes have been observed to periodically form immense swarms of reproductive individuals in surface waters. This interesting behavior is thought to be regulated by the lunar cycle, with a peak near the full moon.