温度和元素浓度对Sr在褐牙鲆仔稚鱼耳石中的沉积影响

Temperature and Water Elemental Concentration Affecting Strontium Incorporation into Otoliths in Larval-Juvenile Flounder Paralichthys olivaceus

中文关键词: 褐牙鲆  矢耳石  Sr  温度  元素指纹  沉积

英文关键词: Paralichthys olivaceus  Otolith  Sr  Temperature  Elemental fingerprinting  Elemental incorporation

中文摘要:

      科学认识鱼类耳石中微量元素沉积与主要水环境因子的关系是基于耳石微化学方法重新构建鱼类生活史及反演其环境履历的重要前提。本研究以环境与耳石中重要元素Sr为例，研究在不同水温(16℃、19℃和22℃)和不同元素浓度(1×、2×和3×Sr)下Sr在褐牙鲆(Paralichthys olivaceus)仔稚鱼耳石形成生长过程中(孵化后15~93 d)的沉积(Sr∶Ca比)特征。结果显示，在不同水温下，耳石中Sr∶Ca比随水体中Sr浓度的升高呈线性增长，而元素分配系数(DSr)随元素浓度的升高先降低然后趋于稳定。在不同Sr浓度下，耳石中Sr∶Ca比及DSr均随水温升高呈增长趋势，二者在22℃时的值均显著高于在其他水温时的值。耳石中Sr沉积能够表征褐牙鲆仔稚鱼所经历的水环境中Sr浓度和水温的变化，可作为元素指纹应用于褐牙鲆早期生活史的重建和环境履历的反演。

英文摘要:

      An understanding of the effects of aquatic environmental factors on elemental incorporation into otoliths is fundamental for reconstructing life and environmental histories of fish using otolith microchemistry analysis. This study investigated the effects of temperature (16℃, 19℃, and 22℃) and water elemental concentration (1×, 2×, 3× Sr ambient baseline, 6.5 mg/L) on the otolith elemental incorporation of Sr in larval-juvenile flounder, Paralichthys olivaceus (15~93 days post hatching). The results revealed that the otolith incorporation of Sr (Sr∶CaOtolith) was positively dependent on ambient Sr concentration (Sr∶CaWater) as well as water temperature. Sr∶CaOtolith values were significantly higher at 22℃ than at 16℃ and 19℃ at all Sr concentrations. Partition coefficient of Sr (DSr, Sr∶CaOtolith/Sr∶CaWater) tended to decrease with increasing Sr∶CaWater but remained stable when Sr∶CaWater reached a certain level at each temperature. Sr was incorporated into the otoliths more efficiently at 22℃ than at the lower temperatures. It appeared that the otolith elemental incorporation of Sr was closely related to the ambient elemental concentration and, thus, could reflect the water chemistry that fish experienced, suggesting that Sr could be used as an elemental fingerprint to reconstruct the life and environmental histories of the flounder during its early life stage in nature.