Jeffree Ross A, Warnau Michel, Oberhansli Francois, Teyssie Jean-Louis
Radioecology Laboratory, IAEA Marine Environment Laboratories, 4 Quai Antoine, MC 98000, Monaco.
Mar Pollut Bull. 2006 Oct;52(10):1278-86. doi: 10.1016/j.marpolbul.2006.03.015. Epub 2006 Apr 25.
Encased embryos of spotted dogfish Scyliorhinus canicula absorbed six radio-isotopes (241Am, 109Cd, 57Co, 134Cs, 54Mn and 65Zn) directly from seawater during short-term experimental exposure, demonstrating the permeability of the egg-case to these contaminants. Embryo to water concentration factors (CFs) ranged from 0.14 for 134Cs to 7.4 for 65Zn. The 65Zn and 57Co CFs increased exponentially with embryo length, whereas the CF for 109Cd declined with length. Among different components of the encased embryo the egg case was the major repository (69-99%) of all six radio-isotopes that were distributed throughout its wall. Egg-case CFs were as high as 10(3) for 57Co and 65Zn, making it the major source of gamma radiation exposure to the embryo and potentially of radio-isotopes for continued absorption by the embryo, following the uptake phase of the experiment. The patterns of uptake by the egg-case approximated linearity for most isotopes and loss rates were isotope-specific; egg-case biokinetics were not greatly affected by the viability of the contained embryo. Within the embryo initial data on radio isotopic distribution show that the skin is their major site of uptake, as previously demonstrated for juveniles.
在短期实验暴露期间，斑点皱唇鲨（Scyliorhinus canicula）的带壳胚胎直接从海水中吸收了六种放射性同位素（241Am、109Cd、57Co、134Cs、54Mn和65Zn），这表明卵壳对这些污染物具有渗透性。胚胎对水的浓缩系数（CFs）范围从134Cs的0.14到65Zn的7.4。65Zn和57Co的CFs随胚胎长度呈指数增加，而109Cd的CFs则随长度下降。在带壳胚胎的不同组成部分中，卵壳是所有六种放射性同位素的主要储存库（69 - 99%），这些同位素分布在其整个壁上。对于57Co和65Zn，卵壳的CFs高达10³，这使其成为胚胎接受γ辐射的主要来源，并且在实验的摄取阶段之后，可能是胚胎持续吸收放射性同位素的主要来源。对于大多数同位素而言，卵壳的摄取模式近似线性，损失率具有同位素特异性；卵壳的生物动力学不受所含胚胎活力的很大影响。在胚胎内部，关于放射性同位素分布的初步数据表明，皮肤是它们摄取的主要部位，这与之前对幼体的研究结果一致。
