Sunlight does not reach the seep sea. Therefore, the deep-sea is a dark environment. Some deep-sea life use luciferase or luminescent bacteria to emit light. Sometimes, there is very beautiful deep-sea jellyfishes or squids at the depth of up to 1,000 m. They were believed to be shining to collect planktons. The Himantolophus groenlandicus, a kind of football fish, is typically deep-sea fish collecting planktons using luminescence. However, nothing is known about the role of luminescence in other deep-sea life. There are almost no bioluminescent organisms in the deep sea at the depth of 5,000 m or more. This region of the deep-sea is almost completely dark environment. The marine snow lost any luminescent in this region.
Can deep-sea life recognize “color”?
The deep-sea environment is almost dark environment. Organisms are reported to have poor vision in a dark environment. The earthworm living in the ground is a typical blind animal. And, the mole also has poor vision that senses only light. The deep-sea environment is as dark as the Furthermore, light is attenuated in the water. Bioluminescence will be difficult to recognize from a distance. As the result, the deep-sea life are thought to be blind. Recently, some deep-sea life have be reported to have vison. In most case, the eye of deep-sea life has one kind of opsin protein. The opsin protein can catch light with specific colors. For example, humans have three types of opsin: red cones, green cones, and blue cones. The eyes of deep-sea life cannot distinguish colors.
Is there colored life in the deep-sea?
In most cases, deep-sea fishes, squids, or jewelfishes have a transparent body. Color may be unrelated to deep-sea life. However, Hirondellea gigas, the amphipods living in the deepest trenches, show different colors. Their color is white, red, yellow, or purple. Red and yellow are originated from carotene molecules. Purple is still unknown.
H. gigas would have vision, because they have two large eyes. In addition, mRNA analysis revealed that H. gigas have opsin proteins (1). H. gigas would be seeing something at the deepest bottom, even though their habitat is completely dark. Or the supposition that deepest part of the world is always dark may be wrong. The functioning eyes of H. gigas suggest a few unknown deep-sea luminescent organism are migrating. Deep-sea is still mysterious world.
We sell the resin-embedded specimen of H. gigas. This specimen will expand the image of the deep sea. If you would like to purchase, please contact us by e-mail (firstname.lastname@example.org). The price of this item is $9,990 plus shipping fee. The numbers of items is limited to only twenty in the world.
(1) Kobayashi H, Nagahama T, Arai W, Sasagawa Y, Umeda M, Hayashi T, Nikaido I, Watanabe H, Oguri K, Kitazato H, et al. Polysaccharide hydrolase of the hadal zone amphipods Hirondellea gigas. Biosci Biotechnol Biochem. 2018;82(7):1123–33. Article