Catching them in nets is one thing. Getting a photo is another thing altogether.

Why do mullet jump?

“Because they can,” boat Capt. Jeff Wilkinson tells visitors on his Eco-Tours of South Mississippi. But it’s a little more complicated than that.

Standing on a bayou bridge watching one jump three times in a row like skipping a rock, and then seeing others get inspired and do the same — it sure looks random.

Occasionally there’s a frantic jump or a group jump that might indicate something’s after them. But so often it looks like what Pascagoula businessman Bruce Grimes calls jumping “just for fun.”

James Skrmetta, spokesperson for USM’s Gulf Coast Research Lab, checked with its scientists and said, “There are only theories ... one is to shake off parasites, another is to break open egg sacks during spawning season and then, of course, when they jump in large schools, it is to escape a predator.”

Wilkinson tells kids they jump “when they poot.” That goes over well.

Since mullet jump all up the Pascagoula River during their tours, he gets asked a lot and has researched it over the years. He also has tried for years to photograph them.

“It’s not as easy as it looks,” he said. He has thousands of photos of ripples on the water.

More seriously, his theory on randomly jumping mullet has something to do with lack of oxygen.

“When they are feeding on the bottom, sometimes they encounter a lack of oxygen,” he said. “And when they come up, they have mud in their gills. They have an air sack that gives them a couple of minutes of air that helps them in that low oxygen situation when they’re feeding down there.”

The jump clears the gills and refills the air sack, he theorizes, so low oxygen doesn’t affect them as much. But on Eco-Tours, they see them jumping more in the fall. That is when they spawn.

Research Lab fisheries biologist Jim Franks said very little study has been done. It’s not a high-priority fish for researchers.

There are just so many other projects for study, he said, and there’s not a mullet industry here anymore.

But it’s an age-old question.

“The short of it is, who knows?” he said. “Still, it’s intriguing to all of us who study fish.”

“There’s a little area on their body where they can capture air,” he said. “And there are parasites, but the bottom line is no one really knows.”

If they do have the ability to capture air, it would be to their advantage in low oxygen conditions, Franks said.

They are filter feeders and vital to estuaries. They clean water and are a good source of food for other fish.

They taste good to people, too. There was a mullet industry on the Coast back when gill nets were legal, and the roe (egg masses) also were popular in Europe and Asia.

Legend is they were a staple for families during the Depression, thus the tag Biloxi Bacon.

“They are delicious,” Franks said. “One of my favorite meals is fresh fried mullet, especially if it’s caught around the barrier islands, where the water is more salty.

“I recall on Fridays for many years around here, mullet was the lunch special at restaurants,” he said.

If you see them in a fish market on ice, chances are they’re fresh.

You catch them with cast nets because they won’t take a baited hook.

And they make good live bait.

It has always been a prolific species, he said, abundant.

There are a couple ways they jump — several leaps straight ahead or coming out of the water and flopping on their sides.

“You see them leaping, they’re a classic coastal fish, a mainstay,” he said. “They’re just iconic.”