Dan Holmes with his catch
A white lobster grown at the Aquarium
White lobsters can "color-up" through
red or blue depending where the
Lobster fisherman Dan Holes recently donated a white lobster to the lobster researchers at the New England Aquarium. Thanks Dan!
The color of American lobsters is determined by a single carotenoid pigment, astaxanthin. This pigment is normally red, but in the shell of a lobster binds to protein and turns blue (or binds to more protein and turns yellow). If a lobster does not eat this pigment, then it is not colored (see middle picture).
The NEAq research program grows white lobsters, and uses these to understand what factors influence deposition of the pigment in the shell. When dietary white lobsters are fed a diet containing pigment they will turn either blue or red (bottom pictures) depending where the goes. If the pigment is quickly deposited in the shell, then the lobster adds blue to its overall color. If the pigment is deposited slowly into the shell, the the lobster first turns red before adding blue overtones.
This color change can be used to study shell growth in living lobsters. Understanding shell growth is important because American lobsters are experiencing high rates of Lobster shell disease, thin areas of shell caused by bacteria on the shell surface that consume the shell. With a model to understand shell growth in live lobsters, experiments can be conducted to assess how various changes in environmental conditions influence how a lobster grows and repairs it's shell.