By Patrick D. Bonin
Photos supplied by Dave Schweitzer 

Ever see a crawfish like this one before? It almost looks like he escaped from our ponds, made his way to saltwater, and got covered in barnacles!

Actually, it’s not all that unusual to find some of these “crusty crustaceans” in our traps this time of year. (And don’t worry, the dirty appearance isn’t harmful and doesn’t affect the taste of the crawfish at all.)

What you’re actually seeing on this crawfish are the eggs of an insect known as “water boatman.” According to the LSU AgCenter, the water boatman eggs are laid on newly molted crawfish and are usually most abundant on the head and below the eyes.

Many non-harmful microorganisms and microscopic plants and animals use the crawfish’s shell as a hard surface for their growth, just like rocks or twigs that have been immersed in water for a long time, according to LSU.

Ed Guidry, operations manager of Fruge’ Aquafarms in Branch, La.,
explained why we don’t normally see crawfish like this earlier in the year.

“Right now, late in the season, the crawfish have pretty much stopped growing,
and that means they’re not molting out of their old shells any more,” he explained.
“So anything that gets attached now, we’ll see when we catch them.

“When this happens earlier in the season, we don’t see it because the crawfish
are constantly growing and molting,” he said.

Biologists refer to water boatman and other “fouling organisms” as ectocommensals.
Hot summer temperatures contribute to the process, as ectocommensals grow and spread rapidly on the crawfish’s shell when the water is warm.
Consequently, the combination of the crawfish not shedding its shell along with rapid
ectocommensal growth results in some mudbugs having a dirty appearance.

So if you ever come across a crawfish like this late in the season,
feel free to toss him in the pot with all the rest.
He might not be as “pretty” as all the others, but he’ll taste just as good!

Thanks to Dave Schweitzer for sending these pictures and giving us a great idea for a blog.
If you have an idea for a blog we could write, let us know… we would love to write it.