Metal accumulation, disturbance of Ca²⁺ homeostasis, and occurrence of abnormalities are well-established consequences of single metal exposure during early development stages of sea urchins. However, the effects caused by low concentrations of metals and metal mixtures need to be better understood in marine invertebrates. Therefore, the present study investigated the effects of environmentally relevant concentrations of Zn (9 μg/L), Cd (30 μg/L) and Ni (5 μg/L) in single and binary exposures (Zn + Cd, Cd + Ni and Ni + Zn) to the early life stages of the purple sea urchin Strongylocentrotus purpuratus. Endpoints checked in all treatments after 48-h exposure were unidirectional metal influx rates, bioaccumulation, and Ca²⁺ influx rates. Additionally, the presence of abnormal larvae and developmental delay was evaluated at 24 h, 48 h and 72 h of exposure. Unidirectional influx rates of all three metals were significantly higher than control background rates in all single exposures and binary mixtures, and were generally not different between them. Net accumulation (body burden) of both Zn and Cd increased significantly as a result of their respective single exposures, while Ni accumulation decreased considerably. When Zn or Cd were presented in binary exposures with other metals, the net accumulations of Zn or Cd were reduced relative to single exposures to these metals, whereas this did not occur for Ni accumulation. Thus, bioaccumulation proved to be a better metric than influx rate measurements to analyze metal competition at a whole organism level at these low metal concentrations. Short-term Ca²⁺ influx also did not appear to be a sensitive metric, as the measured rates did not vary among all single and binary exposures, with the exception of a lower rate in Ni + Zn binary exposure. A critical aspect observed was the relationship between bioaccumulation versus influx measurements, which proved positive for Cd, but negative for Zn and Ni, demonstrating possible capacities for both Zn and Ni regulation by sea urchin larvae. Increases in larval abnormalities relative to controls occurred only after binary mixtures, starting at 48 h exposure and maintained until 72 h. However, delay of the sea urchin development by the presence of gastrula stage at 72 h exposure occurred in Zn and Ni single exposures and all metal mixtures, with very high abnormal development when Ni was present.

金属积累，Ca ²⁺稳态的紊乱以及异常的发生是在海胆发育早期单一金属暴露的公认结果。但是，在海洋无脊椎动物中，需要更好地理解由低浓度的金属和金属混合物引起的影响。因此，本研究调查了单次和双次暴露（Zn + Cd，Cd + Ni和Ni和Cd）中与环境有关的浓度Zn（9μg/ L），Cd（30μg/ L）和Ni（5μg/ L）的影响。 Ni + Zn）到紫色海胆Strongylocentrotus purpuratus的生命早期。在暴露48小时后所有治疗中检查的终点是单向金属流入率，生物蓄积和Ca ²⁺涌入率。另外，在暴露24小时，48小时和72小时时评估了幼虫的异常存在和发育延迟。在所有单次暴露和二元混合物中，所有三种金属的单向流入速率均显着高于对照本底速率，并且两者之间通常没有差异。锌和镉的净积累量（身体负担）由于各自的一次暴露而显着增加，而镍积累量则显着下降。当Zn或Cd与其他金属二元接触时，相对于单次接触这些金属，Zn或Cd的净累积量减少，而Ni累积却没有发生。从而，与在这种低金属浓度下在整个生物体水平上分析金属竞争相比，生物累积被证明是比流入率测量更好的指标。短期钙²⁺流入量似乎也不是一个敏感的指标，因为测得的速率在所有单次和二元接触中均没有变化，但Ni + Zn二元接触率较低。观察到的一个关键方面是生物蓄积量与流入量测量值之间的关系，事实证明镉对镉呈阳性，但锌和镍呈负值，表明海胆幼虫对锌和镍的调节能力。相对于对照，幼虫异常的增加仅在二元混合物后才发生，从暴露48小时开始一直保持到72小时。然而，锌和镍的单次暴露以及所有金属混合物中，暴露于72 h时存在胃形肠胃，导致海胆发育延迟，当存在镍时，异常发展非常严重。