A new study published in the journal海洋科学领域发现居住在珊瑚礁的珊瑚中的光合藻类在暮光区的生命中从未见过。研究人员发现共生菌spp.与较浅深度的藻类物种相比,负责光合作用供电的藻类能够更有效地进行光合作用。
“这与我们在陆地上看到的任何东西,或者我们在浅礁中看到的任何东西都不一样,”纽约市海洋生物学家,研究人员之一的海洋生物学家戴维·格鲁伯(David Gruber)说。
Photosynthesis
在珊瑚内部,共生藻类称为共生藻,可提供光合作用的氧气和能量,以换取营养和保护。对于浅居住的珊瑚,这种交换是自由发生的。但是,低于130英尺(40m)的阳光大大降低了光合作用的能力。
Also as you descend light energy is absorbed and wavelengths narrow until only blue light remains. Beyond 330 feet (100m) only 1 percent of the sunlight above can reach below. This low light environment impacts corals photosynthetic and calcification rates. As corals move deeper their method for energy production shift toazooxanthellatecorals which rely entirely on capturing food, without the ability to photosynthesize.
Light-harvesting antennas
在陆地和水中,植物使用称为轻度收获复合物或光合天线的细胞结构来捕获光子(光的颗粒)。格鲁伯说,在陆地上的昏暗森林中,灌木丛中的植物进化了很大的天线络合物,以捕捉每一滴光。
居住在中间区域中的藻类建造巨大的光合天线可能是有意义的。但这不是研究人员发现的。实际上,当来自耶路撒冷希伯来大学和海法大学的格鲁伯及其同事都在以色列分析了深层藻类时,他们发现藻类天线结构实际上比较浅的藻类小。共生菌藻类。
一种新型的共生体
研究人员看着共生菌藻类INStylophorapistillata从10英尺(3m)到213英尺(65m)的菌落发现浅水和深水共生体之间存在显着差异。他们发现了中间的光收集天线共生菌had an increase of photosynthetic units per cell, and an increase in the effective antenna size—antenna pigments per photosynthetic unit.
在过去的四年的跳水,团队took samples of deep-reef corals and transferred them to shallow environments, and took shallow corals and transferred them to deeper areas. They did this slowly, moving the corals only 16 feet (5 m) every two weeks.
What they found was that the corals collected in water depths of about 10 feet (3m) could hang on to life at 213 feet (65m). Corals from the deep, however, couldn’t survive at shallow depths. They lacked the natural compounds that protect corals from the sun’s damaging ultraviolet light.
The different symbiont population discovered at mesophotic depths hints that it diverged from shallow population to provide an adaptive advantage. These results prompted a closer mechanistic look at the differences in the function of the photosynthetic apparatus.