Final answer:
Creatures in the marine environment can glow underwater due to bioluminescence, which is produced by a chemical reaction involving substances like luciferin and enzymes such as luciferase.
Step-by-step explanation:
The creatures glow underwater thanks to the heatless light known as bioluminescence. Bioluminescence is a type of chemiluminescence where light energy is released by a chemical reaction. This reaction often involves luciferase, an enzyme that acts on a substance called luciferin, causing it to emit light.
Bioluminescent dinoflagellates, like Lingulodinium polyedrum, are marine organisms that can cause waves to appear to glow when agitated. This natural phenomenon is an example of convergent evolution, where multiple distinct lineages have independently evolved the capability to produce light. In the case of dinoflagellates, the light-emitting molecule is structurally related to chlorophyll, which is a light-absorbing molecule primarily used in photosynthesis.
Other types of light emissions in nature, such as fluorescence and phosphorescence, differ from bioluminescence. Fluorescence, for example, occurs when a substance absorbs light and quickly re-emits it, while phosphorescence involves a delayed re-emission of light following its absorption.