Bent Spine in Grass Pickerel

Hello, I work at a place that keeps native fish species and when I came into work I noticed one of our Grass Pickerels had a twisted spine. He's not resting on the bottom or floating on the top so I've ruled out swim bladder issues. He's about 10 inches long and is in a 40 gallon by himself. He had been getting fed 1-2 cubes of frozen bloodworms Mondays, Wednesdays, and Fridays. He's very skinny. His water is changed 1 a week. He is very aggressive and will sometimes charge at the glass or try to run into the glass lid. If anyone has any ideas on what the issue could be please let me know. I will also add that we have recently started feeding him frozen cubes of beef heart instead of bloodworms due to their higher protein. 2 cubes a day so he could start gaining weight.

The fish is starving to death. The bend in the spine looks to be from loss of muscle mass.

How can we help him? It also appears he's gotten some meat on his bones since we've started feeding him the beef heart

Do you have other members of this species or is he the only one? It would be helpful to know how the others are doing. I agree that he isn't eating enough.

How does the fish act when you feed him? Is he aggressively eating, or just picking?

I would recommend feeding raw shrimp or pellets for him, if he'll take them. I've never fed beefheart to fish, but I hear it can cause health problems if used as a staple food.

Something seems wrong here. Is it a place that just happens to have North American native fish in tanks, or is it a place that deals in these fish? You have a large predator for a 40 gallon there.

I would try to get it onto a diet of fish. If it is taking pellets or beefheart, it has learned to grab inanimate food. Why not pieces of fish? It's a fish eater. Try for pieces of white fleshed fish, as darker fish are often oilier, and that creates tank cleaning issues. Head for the supermarket, not the pet store.

It could have worms, and a dose of praziquantel-based meds would help if it doesn't gain weight with decent feeding. Prazi is widely available and inexpensive in US pet stores, under a variety of trade names. Check the active ingredients on the bottle.

The next issue is temperature. I don't keep fish native to my region anymore, but Indiana waters will be cold by now, and getting colder. Most fish have a weather/seasonal cycle, and when I kept natives, not many species could thrive at our indoor temperatures year round. They often needed a cool season, at around 5 celsius.

The pickerel is very aggressive when eating and pounces on his food. He won't take pellets. The beefheart was just recently introduced because his regular diet wasn't helping him gain weight. All of the fish that are at my job are in 40 gallon tanks. He's been there for at least a year or 2 that I know of. There are 2 other pickerels and one has been trained to eat pellets and is also quite skinny while the other was just recently caught and will only take live food. The temp of the water is around 60 degrees F. I will suggest a diet of actual fish but one of my co-workers is very adamant that all of the fish learn to eat pellets.

I've seen this in fish chronically affected by internal parasites. The parasites are taking valuable nutrients from the fish, the fish isn't getting the nutrients it needs to maintain a healthy musculoskeletal structure and the body begins pulling minerals from the bones to try to make up for the lack of dietary nutrients.

I'd treat him with some flubendazole since it's water soluble unlike fenbendozole or levamisole which need to be dosed to food.

Beef heart is fatty and fish don't naturally eat mammal meat, you may have better luck fattening him up with good quality fish and seafood from the grocery store. Use tweezers to move the chunk of food in the water like prey would move to entice him to eat them.

My co-workers decided the pickerel was going to get physical therapy and they are going to massage him to be straight. I will try to convince them to go with one of the treatment options suggested you all but I'm not sure that they'll listen. Wish me luck.

jossswonk said:

My co-workers decided the pickerel was going to get physical therapy and they are going to massage him to be straight. I will try to convince them to go with one of the treatment options suggested you all but I'm not sure that they'll listen. Wish me luck.

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Wow. Fish massage. That's a new one on me. Be sure to take some pictures.

"My co-workers decided the pickerel was going to get physical therapy and they are going to massage him to be straight"... Really???

That's a new one.

jossswonk said:

My co-workers decided the pickerel was going to get physical therapy and they are going to massage him to be straight. I will try to convince them to go with one of the treatment options suggested you all but I'm not sure that they'll listen. Wish me luck.

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do not do that, they will kill it.

deworm it and put it on fish and prawn/ shrimp