Skinny Fish, Big Reason

That thin bass you just caught might not be diseased - you may have caused it! See what we mean inside.

By Bob Lusk



Biologist Bob Lusk and BassPro Shops' Dan Hoy dissect the fish, looking for clues into its poor body condition.

Sometimes things are not always as they seem. As biologists, we sometimes get locked into a comfortable little box and miss something, especially when we hear the same questions, over and over.

Pondmeister Larry Hensley, from Odessa, Texas, has been a pondmeister for years. His family ranch, outside Brownwood, Texas, has several ponds and a five year old 35 acre lake. Not just any 35 acre lake, mind you, but a well thought out and designed 35 acre bass lake. Hensley is a stickler for details. He worked with a nearby fish expert to design, oversee construction and then the stock the lake. He did it "right."

Hensley called world headquarters late September with a problem. It seems some of his bass were "skinny." For the most part, he said, "the fish are healthy, but occasionally we catch a long fish that's exceptionally thin."

Normally, when a client says they are catching a few long, thin bass, it means they are catching a bass on its last legs of life, an old-timer in decline. But, not in a five year old lake.

That Saturday in September, when Hensley called, I asked him to put the fish on ice and send it to me overnight. He headed to the store in Brownwood the next day to buy some blue ice and Styrofoam chest to ship the fish and happened to bump into the fish guy who stocked the lake. He got a 30 minute dissertation on why his fish were skinny. Ordinarily, the information would be right on ... if you prefer "box" thinking.

Not enough food, too much vegetation, harvest "slot" fish ... the traditional advice. Our thoughtful fish guy missed this one. He stayed inside his comfortable box.

The photos force all of us out of our boxes. When questioning Hensley, I knew the majority of his fish were healthy. From his field notes, relative weights of his bass were decent. It was an occasional fish that was abnormal. Keep in mind that a 21 inch bass must have weighed more than five pounds in order to reach 21 inches. When Hensley told me he had a 21 inch bass which weighed less than 3 pounds, I knew there must be an issue. But, I thought the issue was limited to several individual fish rather than the entire population, since relative weights of other fish were normal.



Here are the culprits. This fish seemed to have an affinity to eat soft plastic baits. They clogged her digestive system and prevented the fish from digesting food.

That's why I asked him to ship the fish.

The mission was to autopsy this fish and see if there was something obvious. If not, then I would have him ship the next fish straight to a fisheries pathologist to check for diseases.

The first thing I did was use a sharp fillet knife to open the gut cavity of the fish and cut it back to see what was going on inside the fish. As I made the first cut, the fish's stomach rolled out. It was packed tight. I cut the stomach and pulled out four soft plastic baits, in varying degree of digestion.

This fish had a fetish for soft plastic baits. It ate them. The baits had effectively blocked the fish's digestive system. It wasn't that this bass couldn't eat, because its stomach could certainly handle more volume. But, with its digestive system blocked, it couldn't digest and pass any of its natural food. Consequently, the fish was starving to death.

AlI its organs looked pretty good. Its liver was normal color with a moderately low number of grubs. Its heart was fine. Kidneys were a little distended-looking. Its swim bladder was much larger than normal, taking up considerable room in the gut cavity, but that was probably because the fish was in survival mode and struggling to maintain its equilibrium, plus it had been in an ice chest for 24 hours.

Bottom line, there was only one reason this particular fish was so thin. It has lost almost 50% of its body weight because it couldn't digest food.

Oh ... there was one other pertinent fact. There wasn't a hook anywhere inside that fish. Just four plastic baits.

When I called Larry and emailed the photos, he was amazed. He also said all those baits started off as watermelon color. They turned that funky green inside the fish. He also told me he never throws used baits overboard. He did say that it wasn't unusual to lose a bait when fishing, when a fish pulls the soft plastic off the hook.

While I am certainly not ready to call this a "problem" because of one or two I do think it wise to pay attention.

For now, don't throw any soft plastics overboard. Toss them elsewhere for proper disposal.

Reprinted with permission from Pond Boss Magazine