Chain catshark! 

You don’t have to get out of the water—these sharks (Scyliorhinus retifer) are very small. The catshark was first witnessed to be fluorescent during an August 2005 research cruise in the Gulf of Mexico, but no photos were taken. This is one of the first images to capture this shark’s biofluorescence! Captured by David Gruber, Vincent Pieribone and John Sparks.

New Research Shows That Bioluminescence Evolved Frequently in Fish

New research shows that bioluminescence—a phenomenon in which organisms generate visible light through a chemical reaction—evolved many more times among marine fishes, and likely throughout the entire tree of life, than previously thought. In a study published in the journal PLOS ONE, scientists from the American Museum of Natural History, St. Cloud State University, and the University of Kansas reveal that bioluminescence evolved 27 times in marine ray-finned fishes—and 29 times if sharks and rays are counted. Here are some of these amazing bioluminescent fish:

This ceratioid anglerfish has a built-in fishing rod, a modified fin spine topped with a lure that pulses with bacterial light. Anglerfishes are the only animals known to light up in two ways: the genus Linophryne has glowing bacteria in the lure and their own chemicals that make light in a complex chin barbel.
Image: © J. Sparks, R. Schelly, D. Roje

The deep-sea hatchetfish, which gets its name from the distinct hatchet-like shape of its body, has light-producing organs known as photophores that run along the length of their body and point downward. Hatchetfishes use these structurally complex photophores to mimic any down-welling sunlight and disappear from predators lurking below.
Image: © J. Sparks, R. Schelly, D. Roje

Barbeled dragonfish 
This barbeled dragonfish is a small bioluminescent deep-sea fish with a long protrusion attached to its chin, known as a barbel, which is tipped with a light-producing organ called a photophore. It also has large photophores below its eyes used to illuminate prey and potentially communicate, and along the sides of its body for camouflage.
Image: © J. Sparks, R. Schelly, D. Roje

Stoplight loosejaw
A stoplight loosejaw (Malacosteus niger), which is capable of engulfing prey nearly as large as its own body. It has both red and blue/green photophores under its eyes. Its primary prey source, Euphausid shrimp, cannot detect red light. The loosejaw uses this “private” wavelength of light to illuminate and hunt the shrimp.
Image: © Christopher Martinez

Learn more about this research. 


though usually hidden to the human eye, naturally occurring marine biofluorescence can be seen under certain wavelengths of light (like ultraviolet), which causes the cells of the organisms seen here to absorb the light — and some of the photon’s energy — and then emit back a now less energetic light that consequently has a longer wavelength and thus a different colour. (biofluorescence is not to be confused with bioluminescence)  

photos by (click pic) daniel stoupin, alexander semenov, bent christensenlouise murray, and american museum of natural history (click pic for species)

Biofluorescence Lights Up The Deep

I am so excited to finally getting around to writing this article! I first heard about biofluorescence on this year’s Shark Week during the Alien Shark episode,  and a few weeks ago, this National Geographic article went viral about a glowing sea turtle. I have now become fascinated by this phenomenon, and am dying to read the next publication that comes out!

  • What is biofluorescence?

The marine science world really found out about the extent of biofluorescence in an article published on Plos One in 2014. Biofluorescence happens when organisms absorb light, transform it, and eject it as a different color. Before this article, scientists have known about it in cnidarians (jellyfish and corals) and a wide variety of land animals such a butterflies, spiders, and even flowers since the 1960s. However, it never really was documented in bony fish, sharks or sea turtles!

Biofluorescence is different from bioluminescence. Bioluminescence is light produced by a chemical reaction within a living organism. In contrast, biofluorescence results from the absorption of electromagnetic radiation at one wavelength by an organism, followed by its reemission at a longer and lower energy wavelength. This is what causes us to see these marine animals “glowing” in the dark in a variety of green, orange, and red colorations.

((A) swell shark (Cephaloscyllium ventriosum); B) ray (Urobatis jamaicensis); C) sole (Soleichthys heterorhinos); D) flathead (Cociella hutchinsi); E) lizardfish (Saurida gracilis); F) frogfish (Antennarius maculatus); G) stonefish (Synanceia verrucosa); H) false moray eel (Kaupichthys brachychirus); I) Chlopsidae (Kaupichthys nuchalis); J) pipefish (Corythoichthys haematopterus); K) sand stargazer (Gillellus uranidea); L) goby (Eviota sp.); M) Gobiidae (Eviota atriventris); N) surgeonfish (Acanthurus coeruleus, larval); O) threadfin bream (Scolopsis bilineata). Source: PLOS ONE)

During an expedition led by scientists from the American Museum of Natural Sciences in 2014 around the Solomon Islands, the team discovered over 180 species that glow in a wide range of colors and patterns. 

The vast majority of marine organisms live in a blue world, as water quickly absorbs the majority of the visible light spectrum as depth increases. As a result, the team had to design scientific lighting that mimicked the ocean’s light along with cameras equipped with yellow filters that were able to capture the animals’ fluorescent lights. These lights are hardly visible to the naked eye unless we shine an intense blue light on the organisms.

The scientific team revealed that fish biofluorescence is extremely variable, ranging from simple eye rings, to glowing green mucus secreted on the outside of fishes, to quite complex fluorescent patterns throughout the body, including internally. They also found that it is most prominent and phenotypically variable in cryptically patterned, well-camouflaged lineages that otherwise blend in with their surroundings.

  • What is the purpose of biofluorescence?

We’ve established that biofluorescence looks really badass. But realistically, why do they do these fish, sharks, eels, and now turtles glow?

David Gruber, co-author of the scientific article listed above and badass marine biologist himself, believes that many shallow reef inhabitants and fish have the capabilities to detect fluorescent light, and thus may be using biofluorescence in similar fashions to how animals use bioluminescence to find mates, to camouflage or to attract preys.

During the 2014 expedition, scientists discovered that many biofluorescent fishes have yellow filters in their eyes, possibly allowing them to see the otherwise hidden fluorescent displays taking place in the water. 

Originally posted by dodosite

Now one year later in 2015, this hawksbill sea turtle is the first reptile ever recorded showing biofluorescence. It is possible that the neon lights may help with camouflaging the turtle. Nevertheless, the use of bioluminescence in sea turtles remains a complete mystery for now. Dr. Gruber explained that it may be too early to understand why the turtle radiates these lights.

The research on this fascinating topic is still in its infancy, and this is just another example showing how many mysteries the ocean has in store for us!

“The glowing breed of shark is known as the swell shark, or Cephaloscyllium ventriosum, and is fluorescent thanks to a protein within its skin that glows bright green when activated by blue light. Humans can’t see this spectacular light display, but swell sharks can. Their eyes have yellow filters that block out natural blue light in order to see a new world of colors.

“What the swell sharks are doing is using the blue light to create other colours of light to make their world richer in color,”” said Dr. David Gruber, an associate professor of biology at City University of New York. Gruber thinks that the sharks use their biofluorescence to communicate with each other.“ 

Source: IFLscience

NEW RESEARCH: Glowing Shark Patterns Get Brighter in Deep Water

A team of researchers led by scientists from the Museum has found that catsharks are not only able to see the bright green biofluorescence they produce, but that they increase contrast of their glowing pattern when deep underwater. The study, conducted with a custom-built “shark-eye” camera that simulates how the sharks see underwater, shows that that fluorescence helps catsharks see each other and may even offer them a way to communicate. The work was recently published in the journal Scientific Reports.

“We’ve already shown that catsharks are brightly fluorescent, and this work takes that research a step further, making the case that biofluorescence makes them easier to see by members of the same species,” said John Sparks, a curator in the Museum’s Department of Ichthyology and a co-author on the paper.

Read the full story on the Museum blog. 

Footage and Image: © J. Sparks, D. Gruber, and V. Pieribone
Glowing sea turtle is 1st biofluorescent reptile ever discovered
Endangered hawksbill turtle's shell glows green and red in blue light

Scientists have discovered that a critically endangered sea turtle has an amazing ability never seen before in a reptile — it glows neon green and red when exposed to blue light.

The hawksbill sea turtle’s glow is caused by biofluorescence, the ability of an organism to absorb light of one colour and use it to emit light of a different colour.

David Gruber, a marine biologist at the City University of New York, said many marine creatures biofluoresce because there are advantages to being able to produce other colours in the ocean, where mostly only the blue colour from sunlight can penetrate to any depth: “You’re living in a one-colour world.”

Biofluorescent sea creatures include invertebrates such as jellyfish, corals and shrimp. More recently, Gruber has helped discover more than 200 new species of biofluorescent fish.

But turtles “really surprised us because it’s a whole different group of animals,” he said of the discovery in late July during an expedition funded by the TBA21 Academy.

Continue Reading.


Scientists developed a special camera so we can fully appreciate glow-in-the-dark sharks

The concept of glow-in-the-dark sharks is infinitely intriguing, so naturally, science developed a new camera, the better to see them with. As the Washington Post reported, its lens mimics the eye of a shark, allowing researchers to see sharks as they see one another whilst sharking around in the deep sea. Here’s what they discovered about the colors the sharks glow.

Follow @the-future-now

Hippocampus erectus!

Biofluorescence of the seahorse, Hippocampus erectus, recorded using a Red EPIC camera at the Mystic Aquarium during a nighttime photo shoot. The red on the body is likely due to algae on the outside of the skin; the green from the grass is due to fake seagrass. But, the compound causing the green fluorescence in the eyes  is still unknown! This is one of the first images of seahorse biofluorescence. Photo: David Gruber, Vincent Pieribone, John Sparks. Expert animation: Emma Welles.


Transgenic Biofluorescent Animals Part 2

The green fluorescent protein (GFP) is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range. Although many other marine organisms have similar green fluorescent proteins, GFP traditionally refers to the protein first isolated from the jellyfish Aequorea victoria. Jellyfish-derived GFP has been engineered to produce a vast number of useful blue, cyan and yellow mutants, and fluorescent proteins from a variety of other species have also been identified, resulting in further expansion of the available color palette into the orange, red and far-red spectral regions. Together, these highly useful genetically encoded probes are broadly referred to as fluorescent proteins  The FP gene can be introduced into organisms and maintained in their genome through breeding, injection with a viral vector, or cell transformation. Green fluorescent protein has transformed biomedical research. Using a gene that carries instructions to make GFP, scientists can attach harmless glow-in-the-dark tags to selected proteins, either in cells in lab dishes or inside living creatures, to track their activity. It’s like shining a flashlight on the inner workings of cells. These days, scientists can track how cancer cells spread, how HIV infections progress and even which male ends up fertilizing a female fruit fly’s egg. These and many other studies that offer insight into human health all benefit from a green, glowing protein first found in a sea creature.

Patterns of glowing sharks get clearer with depth

A team of researchers led by scientists from the American Museum of Natural History has found that catsharks are not only able to see the bright green catsharks they produce, but that they increase contrast of their glowing pattern when deep underwater. The study, conducted with a custom-built “shark-eye” camera that simulates how the shark sees underwater, shows that fluorescence makes catsharks more visible to neighbors of the same species at the depths that they live and may aid in communication between one another. The work was recently published in the journal Scientific Reports.

“We’ve already shown that catsharks are brightly fluorescent, and this work takes that research a step further, making the case that biofluorescence makes them easier to see by members of the same species,” said John Sparks, a curator in the American Museum of Natural History’s Department of Ichthyology and a co-author on the paper. “This is one of the first papers on biofluorescence to show a connection between visual capability and fluorescence emission, and a big step toward a functional explanation for fluorescence in fishes.”

Scientific Reports paper:

Caption: This photo is of a biofluorescent chain catshark (Scyliorhinus rotifer). Credit: © J. Sparks, D. Gruber, and V. Pieribone
Exclusive Video: First "Glowing" Sea Turtle Found
Scientists diving recently near the Solomons Islands made an illuminating discovery: The first biofluorescent reptile ever recorded.

The critically endangered hawksbill sea turtle is the first reptile scientists have seen exhibiting biofluorescence—the ability to reflect the blue light hitting a surface and re-emit it as a different color. The most common colors are green, red, and orange.

Biofluorescence is different from bioluminescence, in which animals either produce their own light through a series of chemical reactions, or host bacteria that give off light.

Aaaaaaah this is awesome! Nature is so cool. It just goes to show how much we still have to learn about our oceans.

Scientists have identified more than 180 species of fishes that glow in a wide range of colors and patterns. The research shows that biofluorescence—a phenomenon by which organisms absorb light, transform it, and eject it as a different color—is common and variable among marine fish species, indicating its potential use in communication and mating. The report opens the door for the discovery of new fluorescent proteins that could be used in biomedical research.

Learn more.

This glowing turtle is the first documented case of biofluorescence in a reptile

Not to be confused with bioluminescence (in which animals produce light through a chemical reaction), biofluorescence is a phenomenon in which organisms absorb light, transform it, and eject it as a different color. Typically, these colors are green, red, and orange. A wide number of animals are capable of biofluorescence, including some fish, sharks, rays, copepods, and mantis shrimp. And now, as an exclusive to National Geographic, scientists have reported the first case of biofluorescence in a reptile.

via: io9