Rare blue American lobster arrives at New Hampshire museum

A blue American lobster (Homarus americanus) has joined the live collection at the Explore the Ocean World museum in New Hampshire. Researchers estimate the odds of encountering a blue individual of this species at roughly one in two million. How the color arises In their typical state American lobsters wear a greenish-brown shell that blends with the rocky seabed. The hue comes from a red-orange pigment called astaxanthin. When astaxanthin binds to shell proteins—including the blue protein crustacyanin—the combined effect produces the familiar camouflage tone. A blue shell appears when rare genetic mutations alter either the amount of crustacyanin or the way it interacts with astaxanthin, shifting the visible color to a saturated blue. Diet can also play a role: a lobster that feeds only on small fish and avoids shrimp and crabs ingests less astaxanthin, which changes the shell's appearance.