The blue lobster is a striking rarity, a colorful morph of the common American lobster, Homarus americanus. This vibrant coloration is caused by an unusual genetic anomaly that affects the pigmentation within its shell. Despite its unique appearance, the blue lobster is identical to its brownish-green counterparts in every biological and behavioral way, including its nutritional requirements and feeding habits. Therefore, the diet of a blue lobster in the wild is exactly the same as any other member of its species.
The Natural Diet of Wild Lobsters
Wild American lobsters are omnivorous opportunistic feeders, consuming a wide variety of organisms found on the seafloor. Their diet is driven primarily by what is available and easy to catch in their specific benthic environment. This adaptability allows them to thrive in diverse habitats ranging from rocky coasts to muddy-bottomed deep waters.
Primary food sources include:
- Mollusks such as clams, mussels, and snails
- Other crustaceans, including small crabs and copepods
- Echinoderms like sea urchins and brittle stars
- Small fish and marine worms (polychaetes)
- Plant material such as algae and eelgrass
Lobsters also play a role as the ocean’s cleanup crew by scavenging on dead animals and organic debris that sinks to the bottom. While they will sometimes eat their own recently molted shell for the calcium content, cannibalism on live, healthy adults is extremely rare in the wild.
Foraging Behavior and Eating Habits
Lobsters are largely nocturnal creatures, spending most of the daylight hours hidden within burrows or under rocks and only emerging to forage at night. This behavior reduces their vulnerability to predators like cod and dogfish. They are highly dependent on their sense of smell and taste to locate food, using four small antennules and tiny sensing hairs across their bodies to detect chemical cues in the water.
Once a food source is located, the lobster uses its two specialized claws to process the meal. One claw is typically a large, thick “crusher” claw, used to break open the shells of hard-bodied prey like mussels and crabs. The other is a smaller, sharper “pincer” or “ripper” claw, used for tearing apart softer tissue and manipulating the food.
After the food is torn into manageable pieces, the lobster uses its smaller walking legs, which possess taste sensors, to move the food toward its mouthparts. The lobster’s “teeth” are not in its mouth but are three grinding surfaces located inside a structure called the gastric mill, which is part of the stomach. This internal mechanism effectively chews the food after it has been swallowed.
Diet in Captivity
The diet of lobsters changes significantly when they are captured or farmed, shifting from a varied, naturally foraged menu to a more controlled intake. In the commercial fishing industry, lobsters are primarily caught using traps baited with oily and pungent fish. Salted herring is a common choice for trap bait, as its strong scent attracts lobsters from a distance.
This trap bait, which is a form of carrion, can become a significant part of the wild lobster’s diet, especially in heavily fished areas. In aquaculture or research settings, lobsters are fed prepared diets to ensure optimal growth and health. These captive diets often consist of commercial pellets formulated with fish meal, squid, or shrimp scraps, or simply frozen seafood.
Why the Blue Color Doesn’t Affect Their Menu
The blue lobster’s unusual color is a result of a genetic mutation, not a specialized diet. All lobsters acquire the red-orange pigment astaxanthin from the organisms they consume, such as algae and micro-crustaceans. In a typical lobster, this astaxanthin binds to a protein complex in the shell called crustacyanin, which twists the pigment’s shape and results in the typical dark, mottled coloration.
The rare blue lobster has a mutation that causes a massive overproduction of the crustacyanin protein. This excess of protein binds to nearly all the astaxanthin, causing a maximum color-shift effect that results in the vibrant blue shell. Because the color is determined by a structural protein abnormality and not by the type of pigment ingested, the blue lobster has the same nutritional requirements as any other lobster.