Pink sharks do exist, though not quite in the way most people picture them. The goblin shark, a deep-sea species with translucent skin that reveals the blood vessels underneath, has a distinctly pinkish hue in life. Sharks with genetic conditions like albinism can also appear pink or white, stripped of their normal pigmentation. Beyond these cases, the science of shark coloration turns out to be surprisingly rich, involving structures inside tooth-like scales, hormones that shift pigment around in real time, and even molecules that make certain sharks glow green under blue light.
How Sharks Get Their Color
Most vertebrates produce their skin colors through pigment-containing cells called chromatophores sitting in the skin. Sharks do this too, to a degree, but recent research on blue sharks has revealed something unexpected. The blue coloring on a blue shark’s back does not come from pigment cells the way color arises in, say, a frog or a lizard. Instead, it emerges from tiny photonic structures housed inside the pulp cavities of dermal denticles, the tooth-like scales that cover shark skin.1arXiv. Countershading coloration in blue shark skin emerges from hierarchically organized and spatially tuned photonic architectures inside skin denticles These microscopic structures interact with light in a way that produces color through physics rather than chemistry, somewhat like how a soap bubble creates rainbow hues without containing any dye. The finding suggests that at least some shark species generate color through a mechanism entirely different from what researchers had long assumed.
The general pattern of shark coloration, though, follows a logic shared across many marine animals: dark on top, light on the bottom. This arrangement, called countershading, helps a shark blend in when seen from above against the dark ocean floor and from below against the bright surface. The principle is straightforward, but the execution varies enormously. A whale shark’s dorsal surface is covered in pale spots and stripes on a dark background. A hammerhead is olive-gray above and white below. A mako is deep indigo on its back fading to snow-white on its belly. And a goblin shark, living in near-total darkness hundreds of meters down, is pink.
The Goblin Shark and Natural Pinkness
The goblin shark (Mitsukurina owstoni) is the animal most people think of when they hear “pink shark,” and it genuinely earns the label. Found at depths of roughly 200 to over 1,000 meters in the Atlantic, Pacific, and Indian Oceans, the goblin shark has skin so thin and translucent that oxygenated blood flowing through capillaries near the surface gives the entire animal a rosy, pinkish tone. In freshly caught specimens, the color can be quite vivid, almost bubblegum pink along parts of the body. After death, the color fades and the skin takes on a grayish or brownish cast, which is why older museum specimens and some photographs make goblin sharks look dull rather than pink.
This pinkness is not pigmentation in the traditional sense. The shark does not have pink pigment cells. It simply lacks the heavy pigmentation that masks blood vessels in most other sharks. At the depths where goblin sharks live, virtually no sunlight penetrates, so there is little selective pressure for dark pigmentation to protect against ultraviolet radiation or to provide camouflage against a sunlit backdrop. The pink color is, in a sense, a side effect of living where color barely matters.
Genetic Anomalies That Strip Color Away
Beyond the goblin shark’s natural translucence, individual sharks of ordinarily dark-colored species can turn up looking pink, white, or patchy due to genetic pigment disorders. These conditions are rare, but they have been documented across a surprising number of shark species worldwide.
Albinism is the most complete version. It results from a deficiency in the melanocyte system that produces the pigment melanin, leaving the animal without dark pigment anywhere on its body, including the eyes, which appear pink because the blood vessels in the retina show through unpigmented tissue.2Gulf of Mexico Science. Oculocutaneous Albinism in a Finetooth Shark, Carcharhinus isodon, from Mobile Bay, Alabama A fully albino shark can look strikingly pink or white all over, depending on how much blood shows through the skin. Documented cases include species like the finetooth shark, caught in the coastal waters of Alabama.
Leucism is a related but distinct condition. A leucistic shark has reduced or absent pigmentation across much of its body, but its eyes retain normal color because the defect affects skin pigment cells rather than the retinal pigment cells.3PubMed Central. The Phenomenon of Piebaldism in Sharks: A Review of Global Sightings and Patterns A leucistic great white, for instance, might look ghostly pale or washed-out cream across its dorsal surface while still having dark, normally pigmented eyes. Piebaldism takes this a step further in a different direction: rather than the whole body being lightened, patches of skin lose pigment while other areas remain normally colored, creating an irregular patchwork pattern. Piebaldism is an inherited variation of leucism, and global reviews of sightings have documented it in sharks from multiple ocean basins.3PubMed Central. The Phenomenon of Piebaldism in Sharks: A Review of Global Sightings and Patterns
From a distance, any of these conditions could make a shark look “pink” depending on the species, the extent of pigment loss, and how much blood vessel color shows through the lightened skin. When a viral photo surfaces online claiming to show a pink shark, an albino or leucistic individual of a common species is usually the explanation.
Sharks Can Shift Color on the Fly
Color in sharks is not always fixed. Some species, particularly certain rays and freshwater stingrays that are close relatives of sharks, can actively change how dark or light their skin appears. Research on a South American freshwater stingray found that its skin lightens when isolated from hormonal signals, showing small, contracted pigment cells. When exposed to alpha-melanocyte stimulating hormone or prolactin, the pigment inside those cells disperses, darkening the skin in a dose-dependent way.4Journal of Experimental Zoology. Elasmobranch color change: A short review and novel data on hormone regulation The response involves a molecular signaling pathway shared across many vertebrates, which means the basic machinery for hormonally driven color change exists in the elasmobranch lineage.
Whether open-ocean sharks use this kind of active color modulation in the wild is less clear. Most research on the topic comes from rays and skates rather than true sharks. But the finding is significant because it means that at least some members of the shark-ray group are not stuck with a single fixed shade. Their coloring can respond to physiological state, hormonal fluctuations, and potentially stress or environmental conditions. A stressed shark hauled onto a boat deck might look somewhat different in color from the same animal swimming freely, which is something fishers and divers occasionally notice without having a neat explanation for it.
Sharks That Glow Green and Blue
Pink is not the only unexpected color in the shark world. Under the right lighting conditions, some sharks fluoresce a vivid green. Biofluorescence happens when a molecule absorbs light at one wavelength and re-emits it at a longer, lower-energy wavelength. In the ocean, the dominant ambient light is blue, and biofluorescent sharks absorb that blue light and re-emit it as green.5Cell Press (iScience). Bright Green Biofluorescence in Sharks Derives from Bromo-Kynurenine Metabolism The chemical responsible, identified in catsharks, turned out to be a family of brominated metabolites derived from tryptophan-kynurenine metabolism in the skin.5Cell Press (iScience). Bright Green Biofluorescence in Sharks Derives from Bromo-Kynurenine Metabolism To the human eye in normal light, these sharks look brownish or grayish. But under a blue-light filter that mimics the narrow spectrum available in their natural habitat, they light up in bright green patterns that differ between species and even between males and females.
Biofluorescence is distinct from bioluminescence, which is the ability to produce light chemically rather than just re-emitting absorbed light. Bioluminescent sharks exist too. The velvet belly lanternshark, a small deep-sea species found in the eastern Atlantic and Mediterranean, produces its own blue-green glow from specialized light-producing organs on its underside.6PLOS ONE. De novo transcriptome analyses provide insights into opsin-based photoreception in the lanternshark Etmopterus spinax This ventral glow closely matches the faint downwelling light in the water column, serving as a form of camouflage: by lighting up its belly to match the brightness above, the shark erases its own silhouette when seen from below by potential predators or prey.7Journal of Experimental Marine Biology and Ecology. Phantom hunter of the fjords: Camouflage by counterillumination in a shark (Etmopterus spinax) It is a more active and sophisticated version of the same countershading principle that gives most sharks their dark-top, light-bottom color scheme.
Neither biofluorescence nor bioluminescence produces pink. But they illustrate how much is happening with shark color beyond what meets the casual observer’s eye. The visible appearance of a shark in a photograph on a boat deck may represent only a fraction of the color information the animal carries in life, in its natural light environment.
What Unusual Coloring Costs a Shark
When a shark shows up white, pink, or piebald in waters where its species is normally dark-backed, the consequences can be real. Normal coloration serves practical purposes: camouflage from both predators and prey, and protection from ultraviolet radiation in shallower waters. A color-aberrant shark may lose some or all of these benefits. Research on sharks with skin color anomalies off the coast of southern California noted that reduced pigmentation can compromise camouflage and leave skin more vulnerable to UV damage, while certain unusual color morphs might, in some environments, actually offer alternative camouflage advantages.8Environmental Biology of Fishes. Observations of skin color aberrations in four shark species off the coast of southern California, USA
The fact that albino and leucistic sharks are occasionally caught as adults suggests the disadvantage is not always fatal. A shark that hunts at night, or one that lives deep enough that little sunlight penetrates, would suffer less from the loss of camouflage and UV protection than a shallow-water, daytime predator would. Still, these individuals are decidedly uncommon. Whether that rarity reflects the low frequency of the underlying genetic mutations or a genuine survival disadvantage (or both) is hard to tease apart from opportunistic sightings alone. Systematic population-level data on survival rates of pigment-aberrant sharks simply does not exist yet.
Can Sharks Even See Pink?
Here is an odd wrinkle in the story of shark coloration: the sharks themselves probably cannot appreciate it. Studies examining the photoreceptor cells in shark eyes have found that every shark species tested so far possesses only a single type of cone cell, the photoreceptors responsible for color vision in bright light. Having just one cone type means there is no basis for comparing wavelengths, which is what color vision requires.9PubMed. Microspectrophotometric evidence for cone monochromacy in sharks In practical terms, sharks appear to see the world in shades of gray. The specific wavelength sensitivity of their single cone type varies between species, but the pattern of having only one cone type holds across all sharks examined, suggesting the group may have lost color vision multiple times over evolutionary history.10PubMed. Vision in sharks and rays: Opsin diversity and colour vision
Rays, by contrast, generally have two cone types and likely can distinguish at least some colors.10PubMed. Vision in sharks and rays: Opsin diversity and colour vision The split is curious given how closely related the two groups are. For sharks, though, the implication is that features like biofluorescent patterns, countershading contrasts, and the pinkness of a goblin shark are largely invisible to other sharks as colors. They may still detect them as differences in brightness or contrast, but the rich hues that fascinate human observers are lost on the sharks themselves.
This raises interesting questions about what biofluorescence is actually for. If sharks cannot see color, is the green glow of a biofluorescent catshark just a metabolic byproduct, or does it enhance contrast in a way that monochromatic shark vision can still detect? The chemistry that produces the glow also has antimicrobial properties, so the fluorescent molecules may have been selected for skin protection rather than signaling. Researchers are still working through these possibilities, and the honest answer is that nobody is sure yet.
Pink Sharks on the Internet
The popularity of “pink shark” as a search topic has been fueled partly by real animals and partly by digital manipulation. Photoshopped images of hot-pink great whites circulate on social media every few years, usually accompanied by breathless captions about a newly discovered species. These are fabrications. No shark species is bubblegum pink, magenta, or neon rose. The genuinely pink sharks that exist, primarily goblin sharks and the occasional albino individual, are a muted, fleshy pink that would not make for a particularly viral Instagram post.
Baby Shark merchandise and the broader cultural appetite for pastel-colored ocean creatures have also contributed to the idea of pink sharks as something cuddly or ornamental. The reality, as with most shark biology, is more interesting than the cartoon version. A goblin shark’s pink skin is a window into the evolutionary pressures of deep-sea life. An albino finetooth shark’s pallor is a glimpse into the genetics of pigmentation across vertebrates. And the fact that the shark itself probably cannot see the difference is a reminder that the ocean looks nothing like what we imagine from the surface.
Other Unusual Shark Colors Worth Knowing About
Pink gets the headlines, but sharks come in a wider range of colors than most people realize. The cookiecutter shark is chocolate brown with a lighter collar that may mimic a smaller fish to lure in curious predators, which the cookiecutter then bites with its distinctive circular jaws. The chain catshark sports a geometric pattern of dark lines on a tan background that looks almost hand-drawn. The ornate wobbegong has such elaborate camouflage, tan and brown blotches with fringed skin flaps along its jaw, that it is effectively invisible on a coral reef floor.
Then there are the species whose colors change with age. Juvenile white-tip reef sharks often have darker fin tips than adults. Some juvenile catsharks have bolder patterning that fades as they mature. Whether these developmental color shifts are driven by the same hormonal pathways documented in stingray relatives, or by entirely different mechanisms like differential denticle replacement, remains an open area of research. The study of shark coloration is still catching up to what has been known for decades in bony fish and amphibians, partly because sharks are harder to keep in laboratories and partly because, until recently, few researchers considered the topic a priority. That has been changing, and the findings so far suggest there is plenty left to discover beneath those tooth-covered skins.