异养营养对丛生盔形珊瑚代谢及共生藻光合生理的影响

本文以三亚鹿回头近岸海域内的优势种造礁石珊瑚——丛生盔形珊瑚(Galaxea fascicularis)为研究对象,以丰年虾(Artemia salina)无节幼体为饵料,研究了异养营养对丛生盔形珊瑚光合作用与呼吸代谢的影响。结果表明:异养营养的输入能够增加丛生盔形珊瑚的共生虫黄藻密度以及色素含量,并能够显著提升其光合作用与呼吸速率,然而单个虫黄藻的光合速率降低,这与虫黄藻密度增加引起的遮蔽效应有关。从营养角度来看,异养营养的输入能够使丛生盔形珊瑚有机碳的净积累速率提升约44.5%。本研究结果显示异养营养的输入能够促进丛生盔形珊瑚的光合与呼吸代谢,且这种情况下丛生盔形珊瑚的营养模式更为健康。

Effects of heterotrophy on the metabolism and symbiont photosynthetic physiology of Galaxea fascicularis

Galaxea facicularis, which is dominant in Luhuitou fringing reef, was selected to study the effects of Artemia salina nauplii supplementation on the photosynthesis and respiratory rate of coral holobiont. The results showed that feeding could significantly improve the photosynthesis and respiration rate of G. fascicularis simultaneously, and the zooxanthellae density and pigment concentration of holobiont were increased as well. However, the net photosynthesis rate (P_Net) and pigment concentration per zooxanthellae were decreased when food was supplied, which relates to the shadowing effect caused by the increases of symbiont density after feeding. Despite that, feeding could increase the P_Net/R_D ratio of G. fascicularis by approximately 44.5%, which indicates a higher organic carbon accumulation rate of coral holobiont. In summary, heterotrophic nutrition input could improve the photosynthesis and respiration rate of G. fascicularis, and the feeding mode of G. fascicularis is healthier when heterotrophic sources of nutrition are available.