Every year, a handful of lobsters make headlines because of their color. A bright blue lobster is pulled from a trap off the coast of Maine. A yellow lobster turns up in a supermarket shipment in Massachusetts. A split-colored lobster — half brown, half orange — is caught by a fisherman in Rhode Island. These rare color morphs capture the public imagination because they look like they belong in an aquarium exhibit, not on a dinner plate. But the science behind these colors is just as interesting as the animals themselves.
This guide covers every rare lobster color, what causes it, how common each one is, and what happens to these unusual animals when they are caught.
What Causes Rare Lobster Colors?
Lobster shell color is determined by pigments in the shell — specifically, the interaction between the red pigment astaxanthin and a family of proteins called crustacyanins. In a normal lobster, the astaxanthin is bound to crustacyanin proteins in a configuration that reflects green, brown, and blue wavelengths of light, producing the characteristic dark greenish-brown color that camouflages the lobster on the rocky seafloor.
Rare colors occur when genetic mutations affect either the production of astaxanthin or the structure of the crustacyanin proteins. A mutation that reduces astaxanthin production produces a pale or washed-out shell color. A mutation that alters the crustacyanin protein changes the way the protein binds to astaxanthin, which changes the wavelengths of light that are reflected, producing colors like blue, yellow, or orange. The mutations are random, rare, and usually harmless to the lobster — they affect only shell color, not the health or behavior of the animal.
Some color variations are also caused by diet rather than genetics. A lobster that feeds heavily on certain types of algae or shellfish may develop unusual shell coloration because the pigments from its food are deposited in the shell. Diet-based color changes are temporary — they fade as the lobster molts and the new shell reflects the animal’s recent diet. Genetic color changes are permanent and persist through molts.
Blue Lobsters: One in Two Million
The blue lobster is the most famous of the rare color morphs. It appears bright, vivid blue — ranging from electric blue to deep cobalt — depending on the specific mutation. The blue color is caused by a genetic mutation that causes the lobster to produce an excessive amount of a particular crustacyanin protein. This protein binds to the astaxanthin in a way that shifts the reflected light from green-brown to blue.
The odds of catching a blue lobster are estimated at about one in two million. This number comes from catch records maintained by lobster fishermen in Maine and Atlantic Canada. Given that the Gulf of Maine fishery lands roughly 100 million pounds of lobster per year — representing 50 to 70 million individual lobsters — the expected number of blue lobsters caught each year is about 25 to 35.
Blue lobsters cause a stir whenever they are caught. Almost all of them are donated to aquariums or released back into the ocean rather than being sold for food. The first blue lobster caught in Nova Scotia to be photographed extensively weighed about 2 pounds and was donated to the Aquarium of Western Australia in 2012. Since then, dozens of blue lobsters have made local news headlines across New England and Atlantic Canada.
When a blue lobster is cooked, the blue color fades. The heat denatures the crustacyanin protein and releases the astaxanthin, just as it does with a normal lobster. The cooked blue lobster turns the same bright red as any other cooked lobster. If you happen to catch a blue lobster and cook it, you will end up with a normal-looking red lobster. The blue is only visible in the live animal.
Yellow Lobsters: The Rarest of the Common Colors
Yellow lobsters are significantly rarer than blue lobsters. The odds of catching a yellow lobster are estimated at about one in 30 million. The yellow color is caused by a mutation that reduces the production of astaxanthin while leaving the crustacyanin proteins unchanged. Without enough astaxanthin to bind to the proteins, the shell reflects primarily yellow wavelengths of light.
Yellow lobsters are sometimes called gold lobsters or butter lobsters because their color resembles melted butter. The shade can range from pale lemon yellow to deep buttery gold, depending on how much residual astaxanthin remains in the shell. In extreme cases, the lobster appears almost white with a faint yellow tint — these are sometimes classified separately as pale or pastel lobsters.
Because yellow lobsters are so rare, each catch generates significant media attention. A yellow lobster caught off the coast of Maine in 2018 was named Bubbles and donated to the Maine State Aquarium. A yellow lobster caught in Massachusetts in 2020 was featured on local news stations across New England and became a minor celebrity on social media. Almost all yellow lobsters are donated or released — none are sold for food, both because of their rarity and because their unusual color makes them more valuable as a curiosity than as a meal.
Split-Colored Lobsters: Half and Half
Split-colored lobsters are among the most visually striking of the rare color morphs. These lobsters have two distinct color patterns divided down the middle of the body — one color on the left side and a different color on the right. The most common split colors are half normal (greenish-brown) and half orange, but half blue and half normal, and half yellow and half normal have also been documented.
The cause of split coloration is a genetic anomaly that occurs during early embryonic development. In the first cell division, the fertilized egg splits into two cells that will develop into the left and right halves of the lobster. If a mutation affecting shell color occurs in one of the two cells but not the other, all of the cells descended from that mutated cell will express the mutated color, while cells descended from the unaffected cell will express the normal color. The result is a lobster with two completely different color patterns on each side.
Split-colored lobsters are even rarer than yellow lobsters. The odds of catching one are estimated at about one in 50 to 100 million. Only a handful are caught each year across the entire North American lobster fishery. The most famous split-colored lobster was a half-normal, half-orange specimen caught in Maine in 2019 that was named Fruit Loop by its finder. It was donated to the University of Maine’s Darling Marine Center, where it lived in a research aquarium for several years.
Like other color morphs, split-colored lobsters lose their unusual coloration when cooked. The heat denatures the proteins on both sides of the body, and the entire animal turns the same uniform red. The two sides may be slightly different shades of red — the side that was orange has less astaxanthin, so it will be a paler red — but the dramatic half-and-half pattern disappears completely.
Albino and White Lobsters
White lobsters are the rarest of all the color morphs. The odds of catching a true albino lobster — one with a complete absence of pigment — are estimated at roughly one in 100 million. True albino lobsters have white shells and pink or red eyes. The lack of pigment is caused by a mutation that completely prevents the production of melanin and other pigments, including astaxanthin. Without astaxanthin, the shell contains no pigment at all and appears white, and the red color of the blood vessels is visible through the translucent shell, giving the eyes their pink appearance.
White lobsters are sometimes confused with pale or pastel lobsters, which have reduced but not absent pigmentation. Pale lobsters have a faint trace of color — a hint of blue or yellow — whereas true albino lobsters are uniformly white. The distinction matters because pale lobsters are less rare (about one in 10 million) and have a less dramatic appearance.
Albino lobsters face significant disadvantages in the wild. Their white shells provide no camouflage against the dark, rocky seafloor, making them easy targets for predators like cod, seals, and other lobsters. The lack of pigment may also make them more susceptible to sun damage in shallow waters, though this is less of a concern for animals that spend most of their time at depths where sunlight does not penetrate. Very few albino lobsters survive to adulthood in the wild, which is one reason why they are so rarely caught.
Most white lobsters that are caught are juveniles, and they are almost always donated to aquariums or research facilities. A white lobster caught in Massachusetts in 2021 was named Snowball and became a local celebrity, with visitors driving from hours away to see it at a small aquarium in Gloucester. It was the first confirmed albino lobster caught in Massachusetts in over a decade.
Rare-colored lobsters remind us that even in a well-studied animal like the American lobster, genetic variation can produce surprising results. The next time you see a headline about a blue, yellow, or two-toned lobster being caught, remember that it is not a trick or a hoax. It is a one-in-millions genetic anomaly that gives that lobster a unique appearance — at least until it hits boiling water. And if you want to buy fresh lobster online, you will get the classic greenish-brown shells that have been the standard for centuries. But knowing about their rare, colorful cousins adds a layer of appreciation for the genetic diversity hiding in every trap.
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