【摘要】 1999年4月对南沙群岛海域珊湖礁生态系进行调查,采集了永暑礁和渚碧礁生态系统中不同营养级的生物样品,测定了它们的稳定同位素 13C的丰度δ13C,结果表明,永暑礁中的δ13C 沿着食物链有明显的增加趋势,渚碧礁则不明显.渚碧礁生态系中δ13C 的平均值为 -17.7‰,明显高于永暑礁( -19.5‰),这主要与生物种群的差异,纬度变化及环境因子有关。底栖性鱼类比游泳性鱼类的δ13C 相对高。对于肉食性的珊瑚礁鱼类来说,小型鱼类肌肉中的丰度要高于中型和大型鱼类,这可能是由于代谢反应差异引起的。作为代谢的主要器官肝脏对13C有更高的富集度。温度、生物合成以及初级消费者的食物是以C3 还是C4 植物为主对生物体内的δ13C 起决定作用。更多还原

【Abstract】 Phytoplankton, zooplankton,and coral fishes were collected in the Yongshu Reef and the Zhubi Reef from investigation of the coral ecosystem in the district of Nansha Islands, South China Sea in April 1999. Their stable carbon isotope ratios were analyzed. In the Yongshu Reef 13C is stepwise enriched with increasing of trophic level, while the Zhubi Reef is not obvious. The mean abundance of δ13C in the ecosystem of the Zhubi Reef is -17.7‰ higher than that of the Yongshu Reef (-19.5‰). It maybe results from the different population, latitude and environmental factors. Benthic fishes have higher 13C than nektonic fishes. To carnivorous coral fishes, microfishes also have higher δ13C than mesofishes and macrofishes. As metabolism organ liver has much higher enrichment for 13C. The environmental temperature, biosynthesize and the food of primary consumer C3 plants or C4 plants determine the content of 13C in the body of animal.更多还原