中文摘要：

对柔弱角毛藻Chaetoceros debilis和威氏海链藻Thalassiosira weissflogii分别喂食的安氏伪镖水蚤（Pseudodiaptomus annandalei）的核酸指标（包括RNA含量、DNA含量、RNA︰DNA、RNA︰protein和DNA︰protein）及元素组成[包括氮（N）含量、磷（P）含量、碳氮（C︰N）和碳磷（C︰P）比值]随个体发育的变化进行了描述,并对各阶段的生长率进行了测定。对RNA相关指标与生长率的相关性分析显示,RNA︰protein（RNA：PRO）与生长率不仅具有极类似的变化趋势,而且二者之间存在良好的相关性。这种正相关性同时适用于柔弱角毛藻喂食的所有发育阶段的蚤体和威氏海链藻喂食的桡足幼体和成体,因此,RNA︰PRO适合作为安氏伪镖水蚤生长的标志物。饵料转换实验中,经柔弱角毛藻喂食24h的桡足Ⅱ期幼体分别换作中肋骨条藻Skeletonema costatum和球形棕囊藻Phaeocystis globosa喂食或继续以柔弱角毛藻培养48h后,蚤体的RNA含量和RNA︰PRO指标出现显著差异,呈现中肋骨条藻组〉柔弱角毛藻组〉球形棕囊藻组的趋势,而RNA︰DNA比值则是柔弱角毛藻=中肋骨条藻〉球形棕囊藻。元素组成的差异主要体现在P含量和C︰N比值的变化上,中肋骨条藻和球形棕囊藻喂食的蚤体的各项指标并无明显差异,但均低于柔弱角毛藻喂食的蚤体。据此,推测RNA相关指标对饵料品质的变化响应较为迅速即时,而48h内元素组成反映的主要是摄食历史。因此,现场调查中可利用RNA︰PRO作为标志物迅速有效地指示桡足类的生长状态,而RNA相关的指标则均可用于桡足类营养状态的指示。

英文摘要：

Nauplii, copepodids and adults of Pseudodiaptomus annandalei were fed with Chaetoceros debilis and Thalassiosira weissflogii at the saturated food concentration. Biochemical indices were then measured and described including mass specific RNA content, DNA conten, RNA ： DNA, RNA ： protein, and DNA ： protein, as well as the elemental compositions （mass specific phosphorus content, nitrogen content, atomic C ： P, and C ： N ratios）. Their growth rates were also determined for different developmental stages. The relationships between growth rate and three RNA-related indices were analyzed. It was shown that RNA ： protein （RNA ： PRO）, varying with developmental stage in the same trend as growth rate, was correlated with growth rate significantly in a positive linear manner for all life stages of P. annandalei on C. debilis and for older stages than nauplii on T. weissflogii. Thus, RNA ： PRO could be applied as an indicator of P. annandalei growth. In the experiment of changing diet, the CII copepodids with a 24 h feeding history on C. debilis continued to be fed with Skeletonema costatum or Phaeoecystis globosa for another 48 h, and then showed remarkable differences in RNA content and RNA ： PRO ratio, which ranked as S. costatum 〉 C. debilis〉. P. globosa treatment. Differently, RNA ： DNA ratios ranked as S. costatum =C. debilis〉 P. globosa treatment. On the other hand, elemental compositions of those copepodids in different treatments differed in phosphorus content and atomic C ： N ratio, which ranked as C. debilis 〉S. costatum = P. globosa. It can be deduced that RNA-related indices can respond immediately to food change within 48 h while elemental compositions only reflect feeding history. It was concluded that RNA ： PRO can be applied in field investigation as an indicator of growth in copepod, and RNA-related indices can be used to indicate nutrition status