Evolution and Systematics
Light emitting organs on the underside of hatchet fish help camouflage them through bioluminescent counterillumination.
"Even in ocean depths where sunlight barely penetrates, the faint silhouette that a fish throws to predators beneath it in the water column can make it an easy target. Accordingly, many fish, crustaceans and squid have developed bioluminescent 'counterillumination' abilities. Light-emitting organs called photophores line their undersides. These creatures can adjust the light output of these organs to match the light their eyes receive from above to help eliminate their shadows. The hatchetfish…is one such species equipped with an underbody that lights up to camouflage it from hungry eyes below." (Hadhazy 2009)
Learn more about this functional adaptation.
Hadhazy A. 2009. Shining Examples: 10 Bioluminescent Creatures that Glow in Surprising Ways [Slide Show].
- Johnsen S; Widder EA; Mobley CD. 2004. Propagation and perception of bioluminescence: factors affecting counterillumination as a cryptic strategy. Biol. Bull. 207: 1-16.
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:297
Specimens with Barcodes:294
Species With Barcodes:33
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