In these days of pandemic anxiety, envy the Caribbean spiny lobster's ability to avoid sick cohorts. Marine biologists had noticed that in this typically social crustacean, sickly looking lobsters, infected with a lethal and contagious virus called PaV1, usually become isolated from the pack. To determine if the avoidance is purposeful, scientists set up two adjacent dens in a tank of seawater, tied either a sick or healthy lobster in one den and then introduced a second lobster. If the second creature was already infected, it bunked with its sick or healthy tank-mate equally often. But healthy lobsters were one fourth as likely to share dens with infected lobsters than with healthy ones—even before the sickies became contagious—probably because of chemical signals. The result marks the first observation of wild social animals avoiding diseased individuals, the researchers write in the May 25 Nature.
This article was originally published with the title "Solitary Briny Confinement" in Scientific American 295, 2, 30 (August 2006)