Saigusa M
Biol Bull. 1992 Apr;182(2):257-264. doi: 10.2307/1542119.
The larval release activity of the semi-terrestrial crab Sesarma pictum was monitored for three-week periods under laboratory conditions of constant and cyclic light. Under conditions of constant dim light, the rhythm for the first ten days was unimodal (larval release just after the nocturnal high tide) and then became bimodal (no apparent synchrony with the tides or with other members of the population) for the remainder of the experimental period. On the other hand, in photoperiods similar to those in the field, the rhythm was maintained; the phase was bimodal and the timing of larval release was delayed 1-2 h from the predicted times of high water in the habitat. When the photoperiod was advanced or delayed, the tidal rhythm was phase-shifted accordingly. The photoperiod does entrain the release rhythm to bimodal tidal cycle. So the phase-shift of a tidal rhythm by 24-h LD cycles is a very difficult phenomenon to explain.
在恒定光照和周期性光照的实验室条件下，对近岸蟹Sesarma pictum的幼体释放活动进行了为期三周的监测。在恒定弱光条件下，前十天的节律是单峰的（幼体在夜间高潮后释放），然后在实验期的剩余时间里变为双峰的（与潮汐或种群中的其他个体没有明显的同步性）。另一方面，在与野外相似的光周期条件下，节律得以维持；相位是双峰的，幼体释放时间比栖息地预测的高潮时间延迟1 - 2小时。当光周期提前或延迟时，潮汐节律也相应地发生相位变化。光周期确实将释放节律调整为双峰潮汐周期。因此，24小时明暗周期导致的潮汐节律相位变化是一个很难解释的现象。
