The toxicity of mercury (Hg), is generally known, and around 90% of Hg exist as methylmercury (CH₃Hg⁺) in marine organism. Mercury concentrates in sharks and whales, which are at the top of the food chain as predators to cephalopods. The concentrations of Hg in liver and muscle of blue shark, caught in Sagami Bay, and in digestive gland and mantles of Todarodes pacificus, Sepia madokai, and Uroteuthis edulis caught in East China Sea were measured and analyzed. The Hg concentrations in the sharks, squids, and cuttlefishes determined in this study were almost same as those in the other sea regions. In addition, the Hg concentration in the blue shark was higher in the muscle than in the liver. In S. madokai and U. edulis, Hg accumulated in the digestive gland but not in the mantle. Although the Hg concentration in the digestive gland of T. pacificus is lower than those of S. madkai and U edulis, Hg concentration in the mantle is critically higher. More than 90% of Hg is present as CH₃Hg⁺ in muscle of blue shark and mantle of T. pacificus. This feature is explained due to amino acids with the thiol groups and chain genes in the muscle of blue shark as well as in the mantle of T. pacificus. Myosin in the mantle of T. pacificus and blue shark enhances the stability of CH₃Hg⁺. The amount of Hg in the digestive gland of T. pacificus could be too large to store; thus, Hg is released to the mantle, whereas the nutrients in the digestive gland of T. pacificus are supplied to other tissues. It is considered that the muscle fiber of T. pacificus is strong; therefore, large amounts of myosin levels may be present in T. pacificus than in S. madokai and U. edulis.

汞（Hg）的毒性是众所周知的，海洋生物中约有90％的汞以甲基汞（CH ₃ Hg ⁺）的形式存在。汞集中在鲨鱼和鲸鱼中，它们是头足类动物的捕食者，位于食物链的顶部。测量并分析了在相模湾捕获的蓝鲨的肝脏和肌肉中的汞含量，以及在东海捕捞的Todarodes pacificus，棕褐色的乌贼和Uroteuthis食用菌的消化腺和地幔中的Hg浓度。在这项研究中确定的鲨鱼，鱿鱼和乌贼中的汞含量与其他海域的汞含量几乎相同。另外，蓝鲨中的汞浓度在肌肉中高于肝脏。在S. madokai和U. edulis汞在消化腺中积累，但在地幔中不积累。尽管T. pacificus消化腺中的Hg浓度低于S. madkai和U. edulis，但地幔中的Hg浓度却很高。蓝鲨和太平洋锥虫的地幔中90％以上的Hg以CH ₃ Hg ^+的形式存在。蓝鲨的肌肉以及太平洋芒the的地幔中带有巯基和链基因的氨基酸可以解释这一特征。太平洋锥虫地幔中的肌球蛋白蓝鲨增强了CH ₃ Hg ⁺的稳定性。T. pacificus消化腺中的Hg量可能太大而无法储存；因此，汞被释放到地幔中，而太平洋锥虫消化腺中的营养物质被提供给其他组织。认为T. pacificus的肌肉纤维很结实。因此，大量的肌球蛋白水平可以存在于T. pacificus比在S. madokai和U.贻贝。