鳙(Aristichthy nobilis)、鲢(Hypophthalmichthys molitrix)鱼鳞作为稳定同位素研究非致命采样替代物的有效性

Scale tissue of bighead carp and silver carp as nonlethal surrogates for muscle tissues in freshwater food web studies using stable isotopes

稳定同位素分析技术已成为食物网研究中的关键技术,通用方法是取鱼类背部白色肌肉,在实际应用过程会导致鱼类的死亡,因而有所局限.使用非致命组织作为稳定同位素研究中的替代组织越来越得到关注,但是目前国内尚未开展相关研究.比较鳙(Aristichthy nobilis)、鲢(Hypophthalmichthys molitrix)鱼鳞与肌肉组织中δ13C和δ15N比值,发现鳙、鲢的鱼鳞与肌肉组织中δ13C和δ15N比值均有显著差异.鱼鳞δ13C比值比肌肉更富集,平均高2.54‰,而δ15N比值比肌肉平均低0.7‰.对鳙、鲢的鱼鳞与肌肉组织δ15N比值含量进行相关分析发现,通过构建线性模型,可用校正后的鱼鳞δ15N比值替代肌肉组织δ15N比值.鲢的鱼鳞与肌肉组织δ13C比值存在显著线性相关,而鳙的鱼鳞与肌肉组织δ13C比值无显著相关关系.

Stable isotope analyses of carbon and nitrogen are now widely used in food web studies.Stable isotope analysis of fishes is often performed using muscle that require sacrificing animals.Nonlethal sampling provides an alternative way for evaluating isotopic composition for species of concern or individuals of exceptional value.In this research we compared stable carbon and nitrogen isotope values of white muscle with those from scales （nonlethal） in bighead carp （Aristichthy nobilis） and silver carp （Hypophthalmichthys molitrix） from Lake Poyang.Scale derived δ^13C and δ^15N differed significantly with muscle derived isotope values.Averaged scale δ^13C value was 2.54‰ higher than muscle,while scale δ^15N value was 0.7‰ lower than muscle.Both fish showed strong linear correlation in δ^15N values between their nonlethal sampled scale and their muscle tissue,support the use of nonlethal sampled tissues for stable isotope analyses of fish.Strong correlation in δ^13C only found between H.molitrix scale and muscle.Estimating muscle δ^13C values from scale was not suggest for A.nobilis.