When you picture a Golden King crab, you probably think like its name suggests, it should have a golden color. While this is true 99% of the time, there are rare instances when fishermen pull up something unusual: an albino looking King crab.

Pigmentation in King Crab Shells

King crabs, like many marine animals, get their coloring from carotenoid pigments in their diet. The most important of these pigments is astaxanthin—the same pigment that gives wild salmon their orange flesh coloring, or shrimp their pink shells. Astaxanthin is found in nearly all of the marine organisms that King crab feed on, and the pigment is then absorbed into their depending on what they eat.

Astaxanthin binds with proteins in the King crab’s shell to produce its natural dark red or orangey tone. When cooked, the protein bonds break, revealing the true color of the astaxanthin. That’s why Golden King crab shells turn bright orange after being cooked.

Keyport LLC whole cooked Golden King crab

In rare cases, genetic mutations affect how pigments show up in a King crab’s shell.  When carotenoid pigments are reduced, altered, or expressed differently, the shell appears to be much lighter than normal.

Is It King Crab Albinism?

True albinism is extremely rare in marine life. Key indicators are a complete lack of pigment, most notably in the eyes. In this unusual Golden King crab, you can still see faint traces of pigmentation along its legs which means its not true albinism. A more accurate explanation would be a pigment mutation, or perhaps even leucism. Either way, this is still an extremely rare occurrence.

Why It’s So Rare

Red and Golden King crab rely on their coloring as camouflage in the deep sea thanks to the way light behaves underwater. Red light (how we see the color red) has the lowest energy level and doesn’t penetrate more than around 50 meters underwater. Because of the depth in which Golden King crab live, their orange coloring isn’t visible to predators.

When their shells display lighter pigment variations, they lose that natural camouflage. As a result, these crabs are much more visible to predators and less likely to survive to adulthood. This is one of the reasons why sightings of “albino” or pale Golden King crab are so rare. The next time you see a crab that doesn’t look quite like the others, you’re witnessing a natural genetic twist — proof that the ocean is full of surprises.