A coral reef alive with beauty:
Researchers reveal 180 species of glowing fish
The first comprehensive
survey of biofluorescence in fish has revealed more than 180 different
species of marine life that glow in various patterns of neon colours.
"There is a whole light show going on down there," John Sparks, said.
"There have been studies on corals that are biofluorescent, but for
fish, virtually nothing was known."
The new research could help expand the use of fluorescent proteins in
biomedical research, but has also surprised researchers with the sheer
variety on display. Whilst some species simply have glowing eye rings
others are cloaked complex, full-body patterns that extend right into
the animal's interior.
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Biofluorescent fish absorb light from
their environment before changing its colour with special
proteins and emitting it once more |
"We've long known about biofluorescence underwater in organisms like
corals, jellyfish, and even in land animals like butterflies and
parrots, but fish biofluorescence has been reported in only a few
research publications," said Sparks. "This paper is the first to look at
the wide distribution of biofluorescence across fishes, and it opens up
a number of new research areas."
Biofluorescence is different to the more widely known phenomenon of
bioluminescence.
Animals that bioluminesce make their own light by mixing chemicals
within their body, with 80 to 90 percent of deep sea animals displaying
this property.
Notable examples including the fearsome-looking anglerfish.
In contrast, animals that are biofluorescent do not create light but
absorb it, using proteins to change the light's colour before
re-emitting it.
Whilst bioluminescent animals glow in the dark, biofluorescent ones
rely on ambient light to create the patterns they use for camouflage and
attracting mates.
Because of this, most of the examples of biofluorescence are found in
animals living in relatively shallow environs - places where light from
the surface can still penetrate under water.
The researchers found most of the species they documented in the
coral reefs of the Bahamas and Solomon Islands.
The researchers also found that some species had adapted to emit
patterns that were only visible to members of their own species - an
ability that allows individuals to communicate with potential partners
whilst remaining hidden to predators. Special cameras with blue lights
were used to reveal the full array of colours displayed by the species.
"The cryptically patterned gobies, flatfishes, eels, and
scorpionfishes - these are animals that you'd never normally see during
a dive," Sparks said. "To our eyes, they blend right into their
environment.
"But to a fish that has a yellow intra-ocular filter, they must stick
out like a sore thumb."
- The Independent |