Nonoxygen-producing (anoxygenic) bacteria have bacteriochlorophylls that absorb far-red and near-infrared light, which is all that penetrates to the murky depths.

• 不制造氧的细菌，则有细菌叶绿素吸收远红光和近红外光，因为只有这两种光能穿透水深幽暗处。