Blue lobsters, with their striking coloration, capture attention due to their rarity and unique appearance. These crustaceans are a natural anomaly, standing out against the more common greenish-brown or reddish hues of their counterparts. Their unusual color prompts questions regarding their size and the biological reasons behind their distinctive blue shell.
How Large Do They Get?
Blue lobsters, typically American lobsters (Homarus americanus) with a genetic variation, can grow to sizes comparable to their more common brethren. An average adult American lobster measures between 8 to 24 inches (20 to 61 cm) in length and weighs between 1 to 9 pounds (0.45 to 4.08 kg). Lobsters continue to grow throughout their lifespan, with potential for much larger sizes.
The largest American lobster ever officially recorded was caught off Nova Scotia, Canada. This specimen weighed 44.4 pounds (20.1 kg) and measured over 3 feet long. While such sizes are rare, they demonstrate the maximum growth capacity for this species. Blue lobsters, being the same species, can reach similar record-breaking dimensions.
What Influences Blue Lobster Growth?
Several biological and environmental factors influence a blue lobster’s growth, mirroring the influences on any American lobster. A primary factor is molting, the process where lobsters shed their rigid exoskeleton to allow for an increase in size. Younger lobsters molt frequently, sometimes up to ten times a year, while older, larger lobsters molt less often, perhaps once every few years.
Age plays a role, as lobsters grow continuously throughout their lives, potentially living for several decades in the wild. Food availability and water temperature also affect growth rates; warmer waters and abundant food sources can accelerate metabolism and molting. Habitat quality, providing adequate shelter and reduced stress from predators, contributes to a lobster’s ability to grow to its full potential.
Why Are They Blue?
The blue coloration of these lobsters is due to a genetic anomaly. Normally, lobster shells contain a red pigment called astaxanthin, which is bound to a protein known as crustacyanin. This binding typically results in the characteristic greenish-brown or reddish appearance of most lobsters.
In blue lobsters, a genetic mutation causes an overproduction of the crustacyanin protein. This excess protein binds with a large amount of astaxanthin, creating a blue complex that dominates the shell’s coloration. This genetic variation affects only the pigment production in the shell and does not influence the lobster’s size, growth rate, or overall health.