University of Coimbra, MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, 3000-456, Coimbra, Portugal.
Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 rue Olympe de Gouges, 17000, La Rochelle, France; Institut Universitaire de France (IUF), 1 rue Descartes, 75005, Paris, France.
Mar Environ Res. 2020 Oct;161:105049. doi: 10.1016/j.marenvres.2020.105049. Epub 2020 Jun 20.
Cephalopods represent an important pathway for mercury transfer through food webs. Due to the general difficulties in capturing oceanic squid, beaks found in the diet of top predators can be used to study their life-cycles and ecological role. Using upper beaks of the giant warty squid Moroteuthopsis longimana (major prey in the Southern Ocean), we describe a method to assess mercury concentrations along the life of cephalopods through the segmentary analysis of beak sections (i.e. tip of the rostrum and subsections along the hood). Distinct total mercury concentrations in the different subsections support that beaks can be used to study mercury levels in different periods of cephalopods' life-cycle. Mercury values in the anterior (1.3-7.9 μg kg dw) and posterior (7.8-12.5 μg kg dw) subsections of the hood reflect juvenile and adult stages, respectively. Furthermore, these results confirm that mercury bioaccumulates continuously throughout the individuals' life, with adults doubling their mercury concentrations to juveniles.
头足类动物是通过食物网传递汞的重要途径。由于在海洋中捕捉鱿鱼通常存在困难，因此可以利用顶级捕食者的喙来研究它们的生命周期和生态角色。本研究使用巨型乌贼 Moroteuthopsis longimana 的上喙（南大洋的主要猎物），描述了一种通过分段分析喙段（即吻部的尖端和沿头套的分段）来评估头足类动物一生中汞浓度的方法。不同分段中总汞浓度的差异表明，喙可用于研究头足类动物生命周期不同阶段的汞水平。头套前部（1.3-7.9 μg kg dw）和后部（7.8-12.5 μg kg dw）的汞值分别反映了幼年和成年阶段。此外，这些结果证实了汞在个体的一生中持续生物积累，成年个体的汞浓度是幼年个体的两倍。
