ABSTRACT
The epitokes are divided into semelparous epigamics and iteroparous schizogamics. For the first time, a directory is documented listing the epigamic incidence in 62 species from 12 families and schizogamic incidence in 45 syllid species. Hitherto, not a single author or reviewer has ever considered the energy required for migration over vertical distance. Again for the first time, widely scattered information on vertical distance travelled by 15 epigamics and 13 schizogamics has been assembled. Surprisingly, the vertical distance climbed by the epitokes decreases with increasing body size. Obviously, the larger epitokous glycerids, nereidids and eunicids utilize muscular energy to climb up < 50 m distance. The smaller phyllodocids and ctenodrilids may engage reduction in buoyancy to migrate the vertical distance of > 100–4,000 m. This also holds true for schizogamics. In the epitokes, swarming is timed by a combination of annual, lunar and diel rhythms. Temperature and photoperiod induce the formation of heteronereis in epigamics and stolon in schizogamics. The subsequent events are all induced by specific pheromones.
