Reproductive biology of the polychaeteKefersteinia cirrataKeferstein (Hesionidae). II. The gametogenic cycle and evidence for photoperiodic control of oogenesis

The gametogenic cycle of Kefersteinia cirrata (Polychaeta: Hesionidae) is described for a population in north-east England. Gametogenesis begins in September with previtellogenic and prespermiogenic phases of gametogenesis accumulating until December. Vitellogenesis and spermiogenesis are initiated in January and gravid animals are present in May. Breeding with an unmodified behavioural epigamy takes place in June and July. The effects of environmental temperature and day-length on oocyte growth rates have been determined. There is a synergism between the accelerating effects of long day-length and elevated temperature, the day-length effect being dominant.