Metabolic responses of a phototrophic sponge to sedimentation supports transitions to sponge-dominated reefs
Metabolic responses of a phototrophic sponge to sedimentation supports transitions to sponge-dominated reefs
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DOI：
10.1038/s41598-017-03018-y
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发表时间：
2017-06-02
影响因子：
4.6
通讯作者：
Bell, James J.
中科院分区：
文献类型：
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作者：
Biggerstaff, Andrew;Smith, David J.;Bell, James J.
珊瑚数量的减少与世界各地许多地方沉积物的增加有关，在其中一些地方，海绵数量随后增加。这些变化似乎违反直觉，因为海绵是悬浮饲养者，许多依赖于光合共生体的碳。在印度尼西亚（Wakatobi）的一个沉积礁，珊瑚已经减少，光合自养海绵Lamellodysideaherbacea现在很丰富。我们假设这部分是由于L。草本植物能够清除其组织中的大量沉积物，并通过改变其呼吸速率来补偿相关的代谢需求。海绵组织的有害影响可以忽略不计的治疗后，观察到高达五倍的高度沉积的珊瑚礁的沉积速率。发生快速沉积物清除，这可能有助于粘液的产生。最后，高沉积物暴露导致呼吸速率立即降低，可能是由于减少泵送以防止堵塞，而持续的高沉积导致呼吸速率增加，可能是由于粘液生产的能量成本。我们的研究提供的证据表明，一些海绵可以容忍的环境，似乎不适合许多珊瑚和增加沉积这种驯化可能会支持进一步过渡到海绵占主导地位的珊瑚礁在未来。
Declines in coral abundance have been linked to increased sedimentation at many locations across the world and at some of these locations there have been subsequent increases in sponge abundance. These shifts appear counterintuitive as sponges are suspension feeders and many rely on photosymbionts for carbon. At a sedimented reef in Indonesia (Wakatobi) corals have declined and the photoautotrophic sponge Lamellodysidea herbacea is now abundant. We hypothesise that this is partly due to L. herbacea's ability to clear its tissues of high levels of settled-sediment and compensate for associated metabolic demands by altering its respiration rate. Negligible detrimental effects to sponge tissue were observed after treatments up to five times the sedimentation rate of the highly sedimented reef. Rapid sediment clearance occurred that was potentially aided by mucus production. Finally, high sediment exposure caused an immediate reduction in respiration rate, likely due to reduced pumping to prevent clogging, whereas sustained high sedimentation caused an increase in respiration rate, potentially due to the energetic cost of mucus production. Our study provides evidence that some sponges can tolerate environments that appear unsuitable to many corals and with increased sedimentation this acclimation may support further transitions to sponge dominated reefs in the future.