Felpeto Aldo Barreiro, Rivera Máximo Frangopulos, Vasconcelos Vitor Manuel
CIIMAR, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n 4450-208, Matosinhos, Portugal.
Centro de Investigación GAIA Antártica (CIGA), Universidad de Magallanes, Avenida Bulnes 01855, Punta Arenas 6210427, Chile; Cape Horn International Center (CHIC), Universidad de Magallanes, Puerto Williams, Chile; Millenium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), Las Palmeras 3425, CP 780003, Santiago, Chile.
Harmful Algae. 2024 Aug;137:102659. doi: 10.1016/j.hal.2024.102659. Epub 2024 May 25.
The study of interactions between copepods of the genus Acartia and toxic dinoflagellates of the genus Alexandrium has been an important topic during the last four decades. Feeding behavior and physiological responses of copepods have been studied in laboratory and field experiments, sometimes with contradictory results. More recently, an evolutionary adaptive mechanism leading to enhanced tolerance of Alexandrium toxins in a population of Acartia experiencing chronic exposure to these dinoflagellates has been reported. In the present work, we collected data from the existing studies on the effects of Alexandrium on feeding, reproduction and mortality of Acartia. With these data, we performed a systematic review consisting of a secondary analysis employing general or generalized linear models, weighting data from different studies by the reciprocal of their standard deviation. Our first aim was to overcome shortcomings of individual studies: limited ranges of the variables and overlooked variables (experiment length, population adaptation). These shortcomings could have led to inconsistent conclusions by missing heterogeneous patterns in copepod responses and in the interactions between variables. Our second aim was to test the enhanced physiological performance of chronically exposed relative to naïve copepod populations over a wide geographic range. We found that the feeding rate is enhanced by increased food biomass, irrespective of the food type. Toxins do not have a clear effect on egg production and have a bi-phasic effect on egg hatching success, which was negative above a specific threshold. Toxins also increased mortality. Experiment length had a positive effect on egg production and negative on egg hatching. Naïve copepod populations showed consistently lower ingestion of Alexandrium and egg hatching rates, thereby supporting the spread of the aforementioned mechanism across populations over a wide geographic range.
在过去四十年里，对伪镖水蚤属桡足类动物与亚历山大藻属有毒甲藻之间相互作用的研究一直是一个重要课题。桡足类动物的摄食行为和生理反应已在实验室和野外实验中进行了研究，有时结果相互矛盾。最近，有报道称在长期接触这些甲藻的伪镖水蚤种群中存在一种进化适应性机制，导致对亚历山大藻毒素的耐受性增强。在本研究中，我们收集了现有关于亚历山大藻对伪镖水蚤摄食、繁殖和死亡率影响的研究数据。利用这些数据，我们进行了一项系统综述，包括采用一般或广义线性模型的二次分析，通过将不同研究的数据除以其标准差的倒数来加权。我们的首要目标是克服个别研究的缺点：变量范围有限和被忽视的变量（实验时长、种群适应性）。这些缺点可能导致结论不一致，因为遗漏了桡足类动物反应以及变量之间相互作用中的异质性模式。我们的第二个目标是在广泛的地理范围内测试长期暴露的桡足类种群相对于未接触过的种群是否具有增强的生理性能。我们发现，无论食物类型如何，食物生物量增加都会提高摄食率。毒素对产卵没有明显影响，对卵孵化成功率有双相效应，在特定阈值以上为负效应。毒素还会增加死亡率。实验时长对产卵有正效应，对卵孵化有负效应。未接触过的桡足类种群对亚历山大藻的摄食量和卵孵化率始终较低，从而支持了上述机制在广泛地理范围内不同种群中的传播。
