Sánchez-Vázquez F J, Zamora S, Madrid J A
Department of Physiology and Pharmacology, Faculty of Biology, University of Murcia, Spain.
Physiol Behav. 1995 Oct;58(4):705-14. doi: 10.1016/0031-9384(95)00116-z.
Sea bass, a fish species characterized by its dualistic feeding pattern, was investigated to study the synchronizing effect of light and food on the demand-feeding rhythm. Nocturnal and diurnal sea bass, both in groups and individually, were exposed to restricted-feeding (RF) and light-dark (LD) cycles of different periods. The phase relationship between both zeitgebers was also studied. The results show that food-demand rhythms synchronize to periodic food availability under constant light conditions (DD) and that there is a partial coupling between food-entrained and light-entrained activity under conflicting zeitgebers (LD 13:13 h and RF 4:20 h), suggesting the existence of a feeding entrainable oscillator (FEO) in addition to the master light entrainable oscillator (LEO). In some cases, food availability restricted to the light or dark phase contrary to that of the previous feeding phase changed a diurnal feeding pattern into nocturnal and viceversa, suggesting that food can be one of the switching factors that decides whether the circadian system of sea bass is nocturnal or diurnal. However, the fact that the feeding pattern of some fish was unrelated with the phase in which food was available suggests that other internal and/or external factors could be involved in the temporal flexibility of sea bass.
海鲈是一种具有二元摄食模式的鱼类，为了研究光照和食物对需求摄食节律的同步作用，对其展开了调查。将夜间和日间的海鲈分别成群和单独饲养，使其暴露于不同周期的限食（RF）和明暗（LD）循环条件下。同时还研究了这两种授时因子之间的相位关系。结果表明，在持续光照条件（DD）下，食物需求节律会与周期性的食物供应同步，并且在相互冲突的授时因子（LD 13:13小时和RF 4:20小时）作用下，食物诱导的活动和光照诱导的活动之间存在部分耦合，这表明除了主要的光照可调节振荡器（LEO）之外，还存在一个可被食物调节的摄食振荡器（FEO）。在某些情况下，与先前摄食阶段相反，将食物供应限制在光照或黑暗阶段会使日间摄食模式转变为夜间摄食模式，反之亦然，这表明食物可能是决定海鲈昼夜节律系统是夜间型还是日间型的切换因素之一。然而，一些鱼类的摄食模式与食物供应阶段无关这一事实表明，其他内部和/或外部因素可能参与了海鲈摄食时间的灵活性。
