You’re one in 30 million

Last week I learned that a local retired lob­sterman named Frank gifted Northeastern’s Marine Sci­ence Center a calico lob­ster. Sim­ilar to the par­ti­col­ored cat you’re prob­ably more familiar with, calico lob­sters don a mot­tled pat­tern of orange, black, and green spots on their shells.

Frank’s buddy had appar­ently caught the lob­ster and was set to sell it at a whole­saler in Revere. Frank wouldn’t hear of this, so he called the MSC to see if they were inter­ested in housing it. “I said yes, of course,” said Carole McCauley, the center’s out­reach pro­gram coordinator.

Valerie Perini, Outreach Educator at the Marine Science Center in Nahant, MA, holds a very rare calico lobster in the touch tank area. Photo by Brooks Canaday.

Valerie Perini, Out­reach Edu­cator at the Marine Sci­ence Center in Nahant, MA, holds a very rare calico lob­ster in the touch tank area. Photo by Brooks Canaday.

While calico lob­sters are appar­ently extremely rare — about one in 30 mil­lion lob­sters is a calico — they seem to get their fare share of media cov­erage. Back in 2012, another calico was saved from the Summer Shack boiling pots by chef Jasper White, who named the beauty “Calvin” and deemed him too impres­sive to eat. Calvin’s story made it all the way to the New York Times after finding a per­ma­nent home at the New Eng­land Aquarium.

Just yes­terday, another rare catch from a couple of Maine lob­stermen made head­lines with their calico crea­ture. But the one thing I’m having trouble finding in any of this media flurry is exactly what makes a calico calico. We asked our res­i­dent lob­ster expert Joe Ayers who said, “I don’t think that anyone knows what causes calico pig­men­ta­tion.” And based on my own quick lit­er­a­ture search, I’m willing to believe him for now.

He did say that cal­icos are likely mosaics, meaning they con­tain dif­ferent cells that have dif­ferent pig­ment genes. But there also a dietary role when it comes to lob­ster pig­men­ta­tion. A pig­ment mol­e­cule called astax­an­thin can either be bound to pro­tein or unbound in the body, according to some research from the NE Aquarium from 2004. If astax­an­thin is bound, the lob­ster appears blue; if it’s unbound, it appears red. Feeding lob­sters varying levels of astax­an­thin led to varying levels of its bound and unbound form, which the researchers said sug­gests dif­ferent mech­a­nisms of uptake. A diet con­taining very little of the mol­e­cule ren­ders the lob­ster white, a phe­no­type that’s even rarer than calico in the wild — genet­i­cally albino lob­sters are one in 100 mil­lion, according to the Lob­ster Insti­tute at the Uni­ver­sity of Maine. The team of NEA researchers also said that the thick­ness of the lobster’s shell likely had some­thing to do with their ulti­mate coloring.

Valerie Perini, Outreach Educator at the Marine Science Center in Nahant, MA, holds a very rare calico lobster in the touch tank area. Photo by Brooks Canaday.

Valerie Perini, Out­reach Edu­cator at the Marine Sci­ence Center in Nahant, MA, holds a very rare calico lob­ster in the touch tank area. Photo by Brooks Canaday.

Another rare lob­ster has one color on one half of its body and another on the other half. Appar­ently this is made fur­ther bizarre by the fact that it is almost always cou­pled with a phe­no­type of het­erog­y­nadro­mor­phism, which is a really con­vo­luted way of saying her­maph­ro­dite: lob­sters with half-​​and-​​half col­oring also sport half-​​and-​​half sex organs.

So, this really leaves us no fur­ther along than where we were to begin with. We still don’t know for sure what makes a calico calico. We do know that the trait is extremely rare and extremely cool to look at. I will keep my eyes and ears pealed for more deets on lob­ster pig­men­ta­tion, and please, if you know some­thing I don’t, fill us all in in the comments!