The Barnacle and the Whale

The gray whale gets extensive press coverage every winter and spring as it migrates past the California coast. Traffic backs up for miles along coastal promontories, irate whale watchers shove for position at the overlooks and storms batter the viewers with rain and 50 knot winds. For what? For a fleeting glimpse of our magnificent State Marine Mammal.

I love whales, we all love whales. They are intelligent, majestic and BIG. But consider the lowly hitchhiker on the back of the gray whale, the barnacle. Only on the body of gray whales‑‑no where else in the entire world‑‑does Cryptolepus rhachianeceti live. When this whale was threatened with extinction, the barnacle was also in danger. But did you see any “SAVE THE BARNACLE” bumper stickers? No! Yet in their own petite way they are just as fascinating as their accomplices.

For many years zoologists considered barnacles to be mollusks, relatives of the common garden snail. The confusion was understandable, they do have a shell. Only when scientists were able to observe the entire life history of the animal did they recognize that juvenile barnacles resembled crab larvae and that barnacles are actually crustaceans.

Barnacles are extraordinarily successful and have changed little in hundreds of millions of years. This success is fostered by their reproductive strategy. Each individual has both female and male sexual organs and he/she possesses the longest penis relative to body size in the world. This remarkable appendage is four to seven times the length of their body. With it they impregnate all the barnacles in their immediate vicinity and are, in turn, so fertilized. Barnacles give new meaning to the expression “reach out and touch someone!”

After the eggs are fertilized the parent brood the eggs in its mouth. The eggs soon hatch and squirt out into the sea to begin life as free‑swimming macroscopic larvae. This parental care, albeit slight, gives the new barnacles a slender edge in the sea. Like other young crustaceans they have compound eyes and numerous swimming appendages.

When it’s time to settle down on the appropriate substrate a barnacle secretes cement from glands at the base of its first pair of antennae. The barnacle is now firmly anchored it in place. The glue is tough‑‑ask any boat owner. Dental researchers have identified its chemical nature and barnacle glue may soon be holding your teeth together.

Next a barnacle secretes a calcium shell and loses its eyes. Its feet, no longer needed for movement, now shovel bits of organic matter into the stationary adult’s mouth. So an adult barnacle stands on its head and kicks food into its mouth with its feet. Quite a trick.

Barnacles are ubiquitous and are found in all oceans and bays. They soon coat any object that moves very slowly‑‑a rock, a piling, a log, a ship, a turtle, or a whale.

The attachment of barnacles to gray whales begins in the shallow, warm Baja lagoons where the young of both are born. Within three days of a clean‑skinned baby whale’s birth barnacle larvae have bonded to the youngster for a lifetime of companionship.

We owe the “gray” in gray whale to the barnacle. Young whales are dark brown, nearly black. The barnacles are white and every time one falls off the remaining scar is also white. After several years of infestation the overall color of the whale becomes gray.

These barnacle are a drag, literally. An adult gray whale carries hundreds of pounds of barnacles during its yearly migration of 10,000 miles. These barnacles may live for 6 years before the whale’s skin sloughs off. That means that one barnacle can travel 60,000 miles in its lifetime and never even move! What a life. Summers in Alaska, winters in Baja and a constant opportunity to experience gray whales without getting in a traffic jam.



Posted on

August 22, 2009