Bent Spine in Grass Pickerel

[jossswonk]

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.

 

[GaryE]

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

 

[jossswonk]

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

 

[WhistlingBadger]

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.

 

[GaryE]

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.