Tag Archives: bioluminescence

Ocean acidification may turn on the lights for some glow-in-the-dark species

Credit: Pixnio.

The oceans are becoming increasingly acidic as humans dump more carbon into the atmosphere, with potentially devastating consequences for marine life. We know, for instance, that water with low pH bleaches coral, potentially destroying beloved reefs. But some of the consequences of ocean acidity can be wildly unpredictable. Case in point, a new study found some bioluminescent marine creatures may glow brighter, while others may have their lights dimmed as a result of increasing acidity.

Most people are familiar with fireflies, which are perhaps the most famous bioluminescent creatures in the animal kingdom. However, bioluminescence — which is the production of cold light by animals through a series of chemical reactions or host bacteria that do so — is actually most common in the ocean.

In fact, in the ocean, glowing is the norm. A staggering 76% of all ocean animals are bioluminescent, which shouldn’t be consumed with biofluorescence, the process by which blue light hitting the surface of a creature is reemitted as a different color, such as orange, red, or green.

These animals use their luminescence like built-in flashlights to attract or find food. Some species also use it in order to communicate to predators that they should stay away because they are poisonous — or it might just be a bluff, but will the predator take the chance?

You know that a trait is definitely prized by evolution if it can enhance survival — and bioluminescence has appeared more than 90 times in different species. It has evolved 27 times among ray-finned fishes alone, which represent a huge group that makes up half of all vertebrate species alive today.

However, not all species glow in the same way. Some marine plankton can really put on a light show. For instance, dinoflagellates are known to cluster in the millions and create a stunning shimmering effect, turning the undulating water blue under the moonlight.

But as average ocean pH levels are expected to drop from 8.1 to 7.7 by 2100, scientists wanted to know how bioluminescence may be affected. Researchers at the University of Hawaii at Manoa performed a review of 49 studies on bioluminescence that involved animals across nine different phyla, including Bacteria, Dinoflagellata, Cnidaria, Mollusca, Arthropoda, Ctenophora, and Chordata.

The findings suggest that bioluminescence is indeed affected by ocean acidity, but not necessarily in one particular way. For some species, such as the sea pansy (Renilla reniformis), the pH drop expected by the end of the century should lead to a twofold increase in light production. Other species like the firefly squid (Watasenia scintillans) may experience the opposite effect, as scientists expect a 70% decrease in light production.

Because marine life uses bioluminescence for a wide variety of purposes, the impact increasing acidity will have is difficult to gauge. What’s certain is that it will be felt and may negatively affect certain species. “The rapid (in an evolutionary timescale) increase in light intensity would have a multitude of knock-on effects for the sensory ecology of marine communities,” the authors wrote in the abstract of their study, which was presented at The Society for Integrative and Comparative Biology Annual Meeting.

Marsupial rave: wombats have glow-in-the-dark fur

Besides wombats, scientists found that many other marsupials are also biofluorescent under UV light.

Ever seen a wombat under a blacklight? Not a lot of people have, it seems — it’s only recently that scientists have found that wombat fur is actually biofluorescent, meaning it absorbs blue light and then re-emits it as the color green. The same investigation found that echidnas, possums, and other mammals are biofluorescent.

An accidental discovery revealed that marsupials must love a good rave

It was just a couple of weeks ago that American researchers at the Field Museum accidentally discovered that platypuses glow in dark/purple when UV light is shone on the peculiar mammal’s fur. Now, a new creature can join that lit club: the wombat.

Biofluorescence has long been known to occur in some insects and sea creatures, but no one really thought of verifying the pink-glowing phenomenon in mammals. Naturally, everyone was pretty amazed — and it turns out biofluorescence in mammals is a lot more common than we thought. At least among Australian marsupials.

Platypuses glow green under UV light. Credit: Mammalia.

Spurred by the serendipitous discovery of the biofluorescent platypus fur, the curators of the Western Australian Museum decided to shine UV light on some of their own museum specimens.

Much to their surprise, out of two dozen mammals in their collection, around a third of them had glowing fur. This includes the platypus, echidna, bandicoots, bilbies, possums, some bats, as well as the iconic wombat.

Most of these animals, including wombats, are either nocturnal or crepuscular (active at dawn or dusk). So perhaps the biofluorescence may improve their survivability, especially since ultraviolet light is more prevalent at dusk and dawn.

“Perhaps they are able to see much more than we are able to see,”  Kenny Travouillon, the Western Australian Museum curator of Mammalogy, told Science Alert.

“Predators don’t seem to glow. I think this is because if predators could be seen, they would lose all chance of catching their prey,” he added.

Then again, a lot of marsupials are nocturnal, so perhaps something else may explain the evolutionary drive for biofluorescence. Since these observations have been made in museum specimens on a tiny sample size, perhaps field investigations could provide more answers. In the future, researchers at the Australian Museum want to do just that with the help of different lights.

New species of glowing mushroom found growing on dead bamboo in India

A new species of mushroom has been discovered in the Assam province, northeastern India. It glows.

Image credits Karunarathna, Mortimer, Tibpromma, Dutta, et al., (2020), Phytotaxa.

A team of researchers from India and China reports on two weeks of fieldwork in the Assam region, during which they spotted several new species of mushrooms. The most exciting of these is a species that locals describe as “electric mushrooms” that lives on dead bamboo. The species, christened Roridomyces phyllostachydis is bioluminescent — it produces its own light.

Glow up

“The members of the genus Roridomyces are very fragile and they love moist and humid conditions,” explained Samantha Karunarathna, senior mycologist at the Chinese Academy of Sciences and lead author of the report.

“In general, bioluminescent mushrooms seem to have co-evolved together with some specific insects as these mushrooms attract insects to disperse their spores.”

The species may be new to science, but locals have known about (and used) it for quite a while now. They’ve been employing bamboo sticks with these glowing mushrooms growing on them as natural torches at night, for example.

It only grows on dead bamboo, the team explains, although it’s not immediately apparent why. It may be the case that the bamboo substrate offers special conditions or resources that the fungus prefers, according to Karunarathna, but until the issue is researched more thoroughly, we can’t know for sure. This is the first species of the genus Roridomyces to be discovered in India, the team adds.

The team recovered samples of the mushrooms, dried them, and then performed a genetic analysis to understand where it fits on the tree of life. Both morphological features and its genetic heritage support its position as a new species in the genus Roridomyces. Currently, 12 other species are known in this genus, and five of them are also bioluminescent. The team named the species phyllostachydis after the genus of the host bamboo tree (Phyllostachys) from which it was collected.

Image credits Karunarathna, Mortimer, Tibpromma, Dutta, et al., (2020), Phytotaxa.

During the day, they look pretty unassuming. However, at night they glow with a clear, green light — but only from its stripes and mycelia (which are a rough equivalent to roots) that are burrowing into the bamboo. The mushrooms’ brown caps do not emit light at all.

So why does it glow? Bioluminescence is most commonly seen in ocean environments than on dry land, although fireflies are iconic examples of the latter. Its typically used to attract attention, either for hunting or to coax insects into visiting a plant and spreading its pollen or seeds around. Of about 120,000 described fungus species, around 100 are known to be bioluminescent; only a handful of these are native to India. This is likely due to the fact that there aren’t enough trained specialists to go out and look for new species and document those that have already been discovered, Karunarathna argues.

Bioluminescent fungi commonly grow on decaying wood and are able to feed on the lignin in plant debris (lignin is a structural component in the walls of plant cells, which gives them their stiffness). The largest genus of bioluminescent fungi we know of is the Mycena (bonnet mushrooms), and genetic studies of Mycena suggest that this trait evolved around 160 million years ago.

The paper “Roridomyces phyllostachydis (Agaricales, Mycenaceae), a new bioluminescent fungus from Northeast India” has been published in the journal Phytotaxa.

Glow in the dark waves surprise surfers in California

Imagine yourself being able to surf at night with waves that aren’t only breathtaking but also have an amazing glow. Well, that’s possible every few years along the coast of southern California.

Bioluminescent plankton spotted in Tasmania in 2015.
Image credits Jonathan Esling.

Images were recently captured at beaches in California, where the night-time waters can be seen glowing bright blue. While this has happened before, locals say this year’s phenomenon is special thanks to historic rains that have hit the region and created algal blooms.

The bright blue color of the waves is created by blooming microscopic plants called phytoplankton. The organisms collect on the water’s surface during the day to give the water a reddish-brown hue, known as the red tide. By night, the algae put on a light show, dazzling most brightly in turbulent waters.

The bioluminescence is a chemical reaction on a cellular level within the algae caused by the motion of the waves, according to Scripps Institution of Oceanography Professor Peter J. Franks, who calls the phytoplankton “my favorite dinoflagellate.”

“Why favorite?” Franks wrote in an email Q&A posted on the blog Deep-Sea News. “Because it’s intensely bioluminescent. When jostled, each organism will give off a flash of blue light created by a chemical reaction within the cell. When billions and billions of cells are jostled — say, by a breaking wave — you get a seriously spectacular flash of light.”

The algae blooms have been spotted this year at several beaches in the south of California, including Newport Beach, Hermosa Beach, and Dockweiler state beach. Surfers and many others intrigued by the phenomenon have approached the beaches in the last few weeks to see the glowing waves for themselves.

California has implemented social distancing measures due to the coronavirus epidemic, but people can still visit its beaches. However, they must maintain a 1.8-meter distance between themselves and others. Swimming, surfing, kayaking, and paddleboarding are still allowed.

Dale Huntington, a 37-year-old pastor, got up at 3am after beaches reopened to surf the waves. “I’ve been surfing for 20 years now, and I’ve never seen anything like it”, he told The Guardian. “My board left a bioluminescent wake. There were a few of us out there and we were giggling, grown men shouting and splashing around like kids.”

Researchers at the Scripps Institution of Oceanography at UC San Diego, who study the phenomenon, said the glow shows are most lively at least two hours after sunset. They don’t know exactly how long the phenomenon will last this year. Red tides have been observed since the early 1900s and can last from a few days to a couple of months.

Illustration by Wendy Kenigsberg/Matt Fondeur/Cornell University

Biofluorescence shining light on the search for alien life

The use of ultraviolet flares from red suns and biofluorescence may provide astronomers with vital life signs in the universe

Illustration by Wendy Kenigsberg/Matt Fondeur/Cornell University
Illustration by Wendy Kenigsberg/Matt Fondeur/Cornell University

A new method of searching for life in the cosmos has been pioneered by astronomers from Cornell University.

The team propose that astronomers could utilise harsh ultraviolet radiation flares from red suns — once thought to destroy surface life on planets — to assist in the discovery of hidden biospheres. The team’s study — published in the journal Monthly Notices of the Royal Astronomical Society — suggests that ultraviolet radiation could trigger biofluorescence — a protective glow — from life on exoplanets.

Jack O’Malley-James, a researcher at Cornell’s Carl Sagan Institute and the study’s lead author, says: “This is a completely novel way to search for life in the universe.

“Just imagine an alien world glowing softly in a powerful telescope.”

Biofluorescence, similar to that found in coral, could be used by astronomers to search for life (S.E.A. Aquarium)

Some undersea coral on Earth use a similar form of biofluorescence that the team intend to utilise in the search for life. The coral does this in order to render the sun’s harmful ultraviolet radiation into harmless visible wavelengths, in the process, creating a beautiful radiance.

“Maybe such life forms can exist on other worlds too, leaving us a telltale sign to spot them,” points out Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute.

She points out that in our search for exoplanets, we have searched for ones which look like our own planet. This research plays off the idea the biofluorescence may not have evolved on Earth exclusively.

In fact, as this is a form of defence from harsh UV radiation, logic suggests that its usefulness — and thus, the chance of development — would be increased around stars where UV flares are commonplace.

A large fraction of exoplanets — planets beyond our solar system — reside in the habitable zone of M-type stars. This type of star — the most commonly found in the universe — frequently flare, and when those ultraviolet flares strike their planets, biofluorescence could paint these worlds in beautiful colours.

The next generation of Earth- or space-based telescopes can detect the glowing exoplanets — should they exist.

Ultraviolet rays are transformed into less-energetic and therefore less harmful wavelengths through a process called “photoprotective biofluorescence.” This should leave a very specific signal which astronomers can search for.

Kaltnegger continues: “Such bio fluorescence could expose hidden biospheres on new worlds through their temporary glow when a flare from a star hits the planet.”

The astronomers used emission characteristics of common coral fluorescent pigments from Earth to create model spectra and colours for planets orbiting active M stars to mimic the strength of the signal and whether it could be detected for life.

Proxima b — a potentially habitable world found orbiting the active M star Proxima Centauri in 2016 could qualify as a target for such a search. The rocky exoplanet has been one of the most optimal space travel destinations due to the proximity of the star it orbits — although such jaunts are a concern for the far-future.

Jack O’Malley-James, continues: “These biotic kinds of exoplanets are very good targets in our search for exoplanets, and these luminescent wonders are among our best bets for finding life on exoplanets.”

Large, land-based telescopes that are being developed now for 10 to 20 years into the future may be able to spot this glow.

Kaltenegger concludes: “It is a great target for the next generation of big telescopes, which can catch enough light from small planets to analyze it for signs of life, like the Extremely Large Telescope in Chile.”


Original research: Biofluorescent Worlds II: Biological Fluorescence Induced by Stellar UV Flares, a New Temporal Biosignature. Jack T O’Malley-James, Lisa Kaltenegger.


Chameleons display fluorescent bones on the skull, study shows

The lizard master of disguise is surely a very special creature, we can all agree. Researchers discovered a new outstanding feature of the chameleon: its bones shine with a blue hue in UV light.

Fluorescent tubercles showing sexual dimorphism under UV light at 365 nm (A–D) and fluorescence in further chameleon genera (E–G). (A) Male Calumma crypticum ZSM 32/2016. (B) Female C. crypticum ZSM 67/2005. (C) Male C. cucullatum ZSM 655/2014. (D) Female C. cucullatum ZSM 654/2014. (E) Brookesia superciliaris, male (only UV light at 365 nm). (F) Bradypodion transvaalense, male (dim light and additional UV light at 395 nm). (G) Furcifer pardalis, male (daylight and additional UV light at 365 nm).

Bioluminescence is not that uncommon among marine creatures and some insects (see fireflies), but most terrestrial animals don’t quite possess this eye-endearing feature. The fact that researchers found biogenic fluorescence in chameleons — an entirely earthbound animal — is surprising.

Male C. globifer (ZSM 141/2016) showing congruent tubercle/fluorescent patterns (from left to right); top row: alive in the field under sunlight, micro-CT scan of head surface (probable edge artefact in cheek region), micro-CT scan of the skull; bottom row: alive in the field under UV light, ethanol-preserved under UV light.

Male C. globifer (ZSM 141/2016) showing congruent tubercle/fluorescent patterns (from left to right); top row: alive in the field under sunlight, micro-CT scan of head surface (probable edge artefact in cheek region), micro-CT scan of the skull; bottom row: alive in the field under UV light, ethanol-preserved under UV light.

“We could hardly believe our eyes when we illuminated the chameleons in our collection with a UV lamp, and almost all species showed blue, previously invisible patterns on the head, some even over the whole body,” said David Prötzel, lead author of the new study and a Ph.D. student at the Bavarian State Collection of Zoology (ZSM).

German biologists found that the small bone bumps on chameleons’ heads fluoresce under UV light in a blueish shade. These tiny bone structures absorb UV radiation through small “windows” in the skin and then emit a soft blue light. Actually, the windows are just metaphorical, because the thin epidermis layer that covers the projections is transparent.

After seeing their shimmer under UV-lighting, scientists performed microCT scans and matched the small bone tuberosities to the blue colored pattern.

The fact that bones fluoresce under UV conditions was long-known. But using this phenomenon to intentionally fluoresce different body parts surprised the authors, as it was the first time scientists had encountered such a feature.

Okay, okay, but what’s the deal with all this effort to display such a multitude of colors, even fluorescence?

The myth that chameleons use color-change as camouflage has been debunked. A new theory states that these reptiles use skin color-shifting as a way to communicate with their kin. Taking into consideration that most males from the Calumna genus have significantly more fluorescent tubercles than the females, researchers suppose that their goal is to attract mates. Blue, being a rare color in the forest, should be quite eye-catching in this regard.

The well-known panther chameleon (Furcifer pardalis) which is also popular as a pet, shows fluorescent crests on the head. (David Prötzel; ZSM/LMU)

Another interesting observation is the distribution of fluorescence among different genera of chameleons. Researchers discovered that forest-living species are more prone to exhibit glowing tubercles than species which live in open environments.

“As shorter (UV, blue) wavelengths are scattered more strongly than longer wavelengths the UV component under the diffuse irradiation in the forest shade is relatively higher compared to the direct irradiation by the sunlight,” the authors write in the journal Nature.

“Consequently, using UV reflections for communication is apparently more common in closed habitats than in open habitats, as has been shown in chameleons of the genus Bradypodion.”

Scientists find deep-sea miniature shark that glows in the dark

The shark inhabits the depths of the Pacific and sports an exceptionally large nose.

Etmopterus lailae is a member of the Lanternshark family, living more than 300 meters (1000 feet beneath the surface). Image credits: Stephen Kajiura, Florida Atlantic University.

A light in the darkness

If you go deep enough, underwater life starts to become really bizarre. Where light just barely goes through (or doesn’t at all), pressure starts to mount up, and temperatures drop significantly, creatures have adapted in complex and often strange ways. Eyes can grow very large to capture what little light comes through, or decay completely and abandon any hope of visibility. Membranes and proteins start to develop specific structures to cope with the pressure, and because food is so scarce in the absence of all photosynthesis, fascinating feeding mechanisms have emerged. Among these adaptations, bioluminescence plays a special role.

Bioluminescence is any production and emission of light by a living organism. In the deep oceans, every bit of light can make a difference, and bioluminescence can help in a number of ways. It can serve as a headlight (the so-called photophores of lantern fish), to lure unsuspecting prey (for the anglerfish), or even to attract sexual partners. The oceans are vast and very dark, so that can be a daunting task. Some creatures such as sea cucumbers even use bioluminescence as a “burglar alarm” — whenever they’re attacked by a predator, they light up to attract an even bigger predator to take care of the threat.They can even spray glow-in-the-dark mucus on the predator so that the “police” can find it later.

This newly discovered shark, Etmopterus lailae, is also bioluminescent, but that’s hardly the most remarkable thing about it.

A nose for sharks

Image credits: Stephen M. Kajiura, Florida Atlantic University.

Weighing less than 1 kg (two pounds) and measuring less than 30 centimeters (1 foot), the shark is still a sight to behold. Found in the Pacific Ocean off the coast of Hawaii’s northwestern islands, it looks more like a fairy tale monster than a shark, but that’s to be expected for such a deep dwelling predator.

The shark was discovered 17 years ago, but it took a really long time to properly identify it. At first, Stephen M. Kajiura, the study author thought it wasn’t a new species. When he submitted the findings to a journal, a reviewer told them the shark is not what they think it is. This came as quite a shock — a thrilling one, as Kajiura himself notes.

“There are only about 450 known species of sharks worldwide and you don’t come across a new species all that often. A large part of biodiversity is still unknown, so for us to stumble upon a tiny, new species of shark in a gigantic ocean is really thrilling,” Kajiura said in a university press release.

Working with David A. Ebert, the program director of the Pacific Shark Research Center at Moss Landing Marine Laboratories in California, he was able to identify the shark after all these years. Etmopterus lailae is a member of the Lanternshark family, but it has some striking distinctive features.
“The unique features and characteristics of this new species really sets it apart from the other Lanternsharks,” said Kajiura. “For one thing, it has a strange head shape and an unusually large and bulgy snout where its nostrils and olfactory organs are located. These creatures are living in a deep sea environment with almost no light so they need to have a big sniffer to find food.”

Analyzing and characterizing the shark required diligent categorization and thorough comparisons with other museum specimens. The species also features unusual flank markings that go forward and backward on their bellies, as well as fewer teeth than other sharks.

It’s not clear why this shark is bioluminescent, though the team has some ideas. Most likely, this is how the shark lures in shrimp or other prey and recognizes its mates — as in, to be sure it’s mating with the right species.

This is just the tip of the iceberg, and there’s certainly much more to discover about this species and others like it, but that’s hard to do for obvious reasons. Since 60% of the planet is covered by water more than a mile deep, that makes the deep sea the largest habitat on Earth. It’s also the most unexplored. No doubt, many surprises still await to be discovered. This particular shark, unfortunately for him, is now hosted at the Bernice P. Bishop Museum in Hawaii.
Journal Reference: David A. Ebert, Yannis P. Papastamatious, Stephen M. Kajiura, Bradley M. Wetherbee — Etmopterus lailae sp. nov., a new lanternshark (Squaliformes: Etmopteridae) from the Northwestern Hawaiian Islands. DOI: http://dx.doi.org/10.11646/zootaxa.4237.2.10
Myctophid lantern fish. Credit: Christopher Glenn

The world’s oceans have way more light producing fish than we imagined

On land, the fairytale glow of fireflies is the first to come to mind when we think about bioluminescence. In the oceans, however, there are scores of marine species that have evolved light emitting abilities — as many as four in five ocean fish are bioluminescent, a new research that peered into their genetic history suggests.

Myctophid lantern fish. Credit: Christopher Glenn

Myctophid lantern fish. Credit: Christopher Glenn

Of course, scientists have previously identified many marine species that produce light, from sharks to jellyfish to fish. The tactics employs are as diverse as the species, too, ranging from photon-emitting chemicals produced by the creatures themselves or symbiotic relationships with glowing bacteria. The extent of this adaptation was unclear until now, though.

“bioluminescence is almost a requirement for fishes to be successful”

A team made of scientists at Matthew P. Davis of St. Cloud State University, University of Kansas Biodiversity Institute and John S. Sparks of the American Museum of Natural History Museum analyzed nuclear and mitochondrial gene fragments from over 300 taxa of ray-finned fish to infer the number of independent evolutionary origins of bioluminescence.

Ray-finned fish is a group that comprises most of the ocean’s fish. Even though the focus was on the ray-finned fish, the researchers were stunned to discover bioluminescence evolved no less than 27 times in 14 major fish clades. This process first started as early as the Early Cretaceous, some 150 million years ago.

“When things evolve independently multiples times, we can infer that the feature is useful,” said W. Leo Smith, assistant curator with the University of Kansas Biodiversity Institute, and one of the lead authors of the study published in PLOS ONE. “You have this whole habitat where everything that’s not living at the top or bottom of the ocean or along the edges—nearly every vertebrate living in the open water—around 80 percent of those fish species are bioluminescent. So this tells us bioluminescence is almost a requirement for fishes to be successful.”

Indeed, we should have known bioluminescence was far more common in the deep ocean simply by looking at the bristlemouth — a light emitting fish which is also the most abundant vertebrate on Earth. Thousands of trillions of bristlemouths live in the world’s oceans.

Porichthys notatus is a species of fish in the toadfish family. One fish has over 700 photophores, each about a millimeter wide. They contain luciferin. Norepinephrine activates them, producing a distinct fluorescent green glow. Credit: Wikimedia Commons

Porichthys notatus is a species of fish in the toadfish family. One fish has over 700 photophores, each about a millimeter wide. They contain luciferin. Norepinephrine activates them, producing a distinct fluorescent green glow. Credit: Wikimedia Commons

The bristlemouths, like the anglerfish or lanternfish, emit light for a variety of different reasons. Some rely on it to find prey or, on the contrary, avoid prey. The most significant use of bioluminescence seems to be signaling between the fish, in “the same way that people might dance or wear bright colors at a nightclub,” Smith said.

The authors also report an unusual evolutionary pattern that highlights once more how important emitting light is for the fish. Once a line of fish evolved the ability to produce light, it soon branched into other species. Smith and colleagues aren’t sure why this happens. In May, Smith’s team returned from an expedition off the West Coast where they collected fresh fish for genetic analysis. The aim is to analyze the fish’s mRNA from the light sensitive organs themselves so the researchers might “trace the variation within the system, including the possibility of uncovering how this system evolved.”

“Many fishes proliferate species when they evolve this trait — they differentiate, but we don’t know why,” Smith said. “In the ocean, there are no physical barriers to separate groups of deep-sea fishes, so why are there so many species of anglerfishes, for example? When they start using bioluminescence for species recognition, they diversify into a lot more species.”

Octopoteuthis deletron. Image: UC Berkeley

Squid deep-sea species can eject parts of its arms to confuse enemies [/w video]

Octopoteuthis deletron. Image: UC Berkeley

Octopoteuthis deletron. Image: UC Berkeley

Seems like there’s always a study that comes along once in a while describing yet another peculiar squid ability. The latest was discovered by postdoctoral researcher at the University of Rhode Island who discovered a never before seen defensive tactic in any other type of squid species which involved jettisoning parts of its arm when attacked.

Just one foot long, the squid in question, Octopoteuthis deletron, lives in the deep waters of northeast Pacific Ocean. Stephanie Bush, the lead aquatic researcher involved in the study, first suspected this behavior when she noticed several captured specimens had stumps. Scientists had speculated that they may release their arms, just as lizards can release their tails when attacked, but no one had seen it happen. She embarked on one of Monterey Bay Aquarium Research Institute’s submersibles, which also had a deep-water underwater camera installed, and went on the lookout for specimens to poke. No, really. The submersible’s mechanical arm, which in typical operations is used to grab things, was now instructed to prod some of the squid that were found. Initially, they didn’t come to any conclusive results, but after attaching bottle brush to the arm Bush immediately noticed how poked squids detached arm parts, and convulsively scattered away leaving a small cloud of ink behind it – an ubiquitous defense mechanism present both in squids and octopi.

“The very first time we tried it, the squid spread its arms wide and it was lighting up like fireworks,” she said. “It then came forward and grabbed the bottlebrush and jetted backwards, leaving two arms on the bottlebrush. We think the hooks on its arms latched onto the bristles of the brush, and that was enough for the arms to just pop off.”

The squid are able to re-grow their missing arms, but this mechanisms comes at a great cost, like any defense mechanism.

“There is definitely an energy cost associated with this behavior, but the cost is less than being dead,” Bush said.

The pieces of ejected pieces of arms are bio-luminescent, and keep on moving for a few good seconds after becoming detached. The bio-luminescence is thought to distract enemies or prey while the squid either escapes or attacks. In further experiments, Bush found that some octopus squid appeared hesitant to sacrifice their limbs, but some did so after being prodded several times. Subsequent research showed that the arm bits do grow back, but it takes quite a while, so the squids aren’t inclined to lose them unless absolutely necessary.

Bush’s research on squid began in 2003 when she decided to investigate the assumptions that some scientists had made about deep-sea animals.

“Scientists had assumed that squid living in the deep-sea would not release ink as a defensive measure, but all the species I’ve observed did release ink,” she said. “They assumed that because they’re in the dark all day every day that they’re not doing the same things that shallow water squids are doing. They also assumed that deep-sea squid don’t change color because of the dark, but they do.”

Findings were reported in the journal Marine Ecology Progress Series.

bacteria bio-design light

Amazing bio-design uses bacteria to light up your living room

bacteria bio-design light

We at ZME Science love futuristic designs, but above all we love innovative energy efficient solutions. The latest avantgarde lighting set-up from Philips would fit better in an art gallery than in a home, however what it lacks in practicability, it more than makes up in beauty, and moreover in principle – that energy is all around us, and that living beings are capable of generating energy.

This system isn’t powered by grid electricity, nor solar or wind energy, but by bacteria.

“The concept explores the use of bioluminescent bacteria, which are fed with methane and composted material (drawn from the methane digester in the Microbial Home system). Alternatively the cellular light array can be filled with fluorescent proteins that emit different frequencies of light.”

The bacteria feed on methane and composted material (drawn from the methane digester in the Microbial Home system), which then allows them to emit soft green light by bioluminescence. The light itself is fade, and is far from being capable of powering an office space, however it’s more than suited for a mood setter in your bedroom or simply as a living piece of art.

bacteria bio-design light

Philips believes that the concept could extend into more practical fields than one would expect. Bioluminescence produces low-intensity light, more suitable for tracing, warning, ambience and indication than functional illumination, so tomorrow’s road markers or sensor lights might be powered by bacteria. If you think a bit about it, it doesn’t depend on electricity grid, the sun, wires and so on, making it a perfect possible solution for applications where the environment is subjected to constant unexpected changes.

“This represents a new genre of ‘living’ biological products. We have involved the microbial community in the home to provide the soft mood lighting typical of luminescence by using energy stored in our waste streams. Potentially biological products could be self-energizing, adaptive, responsive, self-repairing, act as biological sensors to environmental conditions, and change the way we communicate information.”

Philips via Treehugger. Photos courtesy of Philips.

San Diego Red Tide

Glow in the dark waves on the San Diego shoreline

Photo by catalano82.

Strollers along the San Diego shoreline experienced their own kind of Northern Lights these past few days, only the western coast equivalent is less about skyline astral projections, and more about a grand neon blue light show luminating from within the ocean’s waves. And less cold.

The event is actually a bioluminescence  phenomenon and is caused by a algae bloom called the “red tide.” The organism,  a phytoplankton called Lingulodinium polyedrum, has bloomed since late August, turning the water a brownish-red color in the daytime. In the night time, however, the coastline is lit with a mystical electric-blue hue.

The bioluminescence is a chemical reaction on a cellular level within the algae caused by the motion of the waves, according to Scripps Institution of Oceanography Professor Peter J. Franks, who calls the phytoplankton “my favorite dinoflagellate.”

“Why favorite?” Franks wrote in an email Q&A posted on the blog Deep-Sea News. “Because it’s intensely bioluminescent. When jostled, each organism will give off a flash of blue light created by a chemical reaction within the cell. When billions and billions of cells are jostled — say, by a breaking wave — you get a seriously spectacular flash of light.”

On the San Diego beaches even footprints in the sand are illuminated where the plankton has washed ashore. Anybody from San Diego reading ZME Science? I’d love to hear some on-site reactions, or maybe you could share some photos on our facebook page.