In early 2011, Dr. John Sparks and his team at the American Museum of Natural History went on a dive off the coast of Little Cayman Island to photograph biofluorescent corals.
When they studied the resulting photographs, Dr. Sparks and his colleagues found something surprising: a biofluorescent eel. Although many sea creatures are bioluminescent-capable of producing light through a chemical reaction -this was the first time one had been found that could biofluoresce, or absorb and re-emit preexisting light.
The discovery of the eel was only the beginning for Dr. Sparks and his team. Subsequent trips to the Bahamas and the Solomon Islands eventually revealed over 180 fish species capable of transmuting the blue light of the ocean into brilliant red, green, and orange hues.
For these discoveries to be seen, Dr. Sparks and his colleagues first had to address a significant technical conundrum presented by the unique properties of biofluorescence.
The light that biofluorescent creatures emit is not visible to the human eye. As a result, biofluorescence is impossible to photograph using traditional methods and equipment.
The scientists ultimately decided to shine a high-energy blue light on the fish they were attempting to photograph. This light mimicked the light of the ocean and triggered the fish's biofluorescence. The researchers also outfitted their camera lens with a specially designed filter that removed the unwanted blue light from the image, allowing the fluorescent light to be more clearly seen.
Further research by Dr. Sparks and his team has revealed that many biofluorescent fish rely on similar filters. These filters, like internal camera filters, allow fish to perceive the biofluorescent patterns on other sea creatures. Why exactly these patterns are important has yet to be determined. However, Dr. Sparks has presented a cogent theory, which has been well received among his peers. His compelling hypothesis is that the patterns play an important role in within-species communication.
What is the meaning of cogent as used in the passage?
What is the meaning of cogent as used in the passage?