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首页> 外文期刊>The Open Fish Science Journal >Endogenous Activity Rhythms of Larval Fish Assemblages in a Mangrove-fringed Estuary in North Brazil
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Endogenous Activity Rhythms of Larval Fish Assemblages in a Mangrove-fringed Estuary in North Brazil

机译：巴西北部红树林边缘河口幼虫鱼组件的内源性活动​​节律

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摘要

In Caeté Estuary, the decrease of larval abundance downstream was attributed to reduced retention, since ebb tide densities prevailed mainly in the middle and lower estuary during the rainy season due to increased freshwater outflow. Anchovia clupeoides, Stellifer microps and Guavina guavina were most abundant in the late dry season on flood tides in the upper estuary, whereas ebb tide densities of these species prevailed in other regions. Environmental fluctuations associated with lunar periodicity, such as tidal amplitude, may account for weekly variability of recruitment and reproduction of some fish species. A. clupeoides showed increased spawning activity during first quarter moon, whereas new moon phases seemed to be reproduction periods of Cynoscion acoupa. Vertical migration was not employed by the most abundant species to enable river retention, since larval densities of these species were not significantly higher at the bottom on ebb tides, except for C. acoupa and Stellifer rastrifer. This result may be related to system turbulence or to the dominance of younger stages unable to migrate vertically at the time of sampling. Lateral movement to the river bank is proposed as a possible retention mechanism. Diel effects on larval abundance related to trophic activity and gear avoidance.
机译：在Caeté河口，下游幼体丰度的下降归因于保留的减少，因为由于淡水的流出增加，雨季的潮汐密度主要发生在雨季的中下游河口。在干河后期，上部河口的潮汐潮中鱼，硬壳micro和番石榴的数量最多，而其他地区的潮汐密度最高。与月球周期性变化相关的环境波动（例如潮汐幅度）可能会导致某些鱼类的募集和繁殖每周发生变化。拟南芥显示出在第一个四分之一月期间的产卵活动增加，而新月相似乎是Cynoscion acoupa的繁殖期。垂直迁移没有被最丰富的物种用来保持河流，因为这些物种的幼虫密度在退潮时底部没有明显升高，除了阿库帕（C. acoupa）和硬皮St（Stellifer rastrifer）。这个结果可能与系统的湍流或年轻的阶段在采样时无法垂直迁移的优势有关。建议向河岸的横向移动是一种可能的保持机制。 Diel对幼虫丰度的影响与营养活动和避免齿轮有关。

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