Investigation of Environmental Cues and Physiological Processes that Regulate Larval Diapause in Calnus Finmarchicus

小行星9313672 芬兰哲水蚤的种群构成了西北大西洋浮游动物生物量的主要部分，并构成了生活在乔治海岸的鳕鱼和黑线鳕的基本食物来源。 据报道，这种桡足类在春季抵达银行是由于招聘的第五阶段桡足类从更深的沃茨的缅因州，在那里他们越冬的休眠或滞育状态。 补充的成功在很大程度上取决于滞育阶段的持续时间。 了解环境因素对滞育诱导和终止时间的影响，以及在整个关键生命阶段发生的内部形态变化，将有助于更好地了解调节Calanus finmarchicus到Georges Bank的招聘过程的物理和生物因素。 该项目下进行的研究是深入调查温度和光周期变化可能影响控制和调节芬兰哲水蚤滞育的生理过程的方式。 一种专门设计的培养多代C.将使用finmarchicus使幼鱼阶段经历各种温度和光周期组合。 光学显微镜和TEM将用于确认控制蜕皮停止和诱导的线索接受器官和神经内分泌部位的身份。 在滞育和nondiapausing个人的性腺发育的细胞学特征将被描述和比较在实验室和现场人口。 ***

9313672 Marcus Populations of Calanus finmarchicus constitute a major portion of the zooplankton biomass in the Northwestern Atlantic, and comprise a fundamental food source for the cod and haddock that live on Georges Bank. The springtime arrival of this copepod on the Bank is reportedly due to recruitment of fifth stage copepodites from the deeper waters of the Gulf of Maine, where they overwinter in a state of dormancy or diapause. Recruitment success depends, to a large extent, on the duration of this diapause stage. Knowing the effects of environmental factors on the timing of diapause induction and termination, and the internal morphological changes that occur throughout this critical life stage, will contribute to a better understanding of the physical and biological factors that regulate the recruitment process of Calanus finmarchicus onto Georges Bank. The research to be conducted under this project is an in-depth investigation of ways in which variations of temperature and photoperiod may influence the physiological processes that control and regulate diapause in Calanus finmarchicus. A specially designed system for culturing multiple generations of C. finmarchicus will be used to subject the juvenile stages to various combinations of temperature and photoperiod. Light microscopy and TEM will be used to confirm the identity of the cue-receptive organs and neuroendocrine sites that control the cessation and induction of molting. Cytological features of gonad development in diapausing and nondiapausing individuals will be described and compared in both laboratory and field populations. ***