What causes this to happen to a fish?

[catman529]

This is the 3rd or 4th crooked grass carp I have caught. This was a couple nights ago. I am thinking an injury to the spine or something, maybe the fish was dropped on the ground and landed the wrong way? Anyone have an idea what would cause this?

Also, a friend of mine caught a small channel cat in the Harpeth several weeks ago that was crooked in 2 places and completely deformed looking.

I've been curious about this and thought someone here might have a clue...

 

[kdxdude]

I don't know what causes it but I have caught several Smallmouth that were that way too.

 

[rsimms]

I don't know scientific names or details, but I know there is a parasite that attacks them when they are young fry. The parasite affects the spine... and kills some fry.

But if they survive, they are fine except where the parasite invaded the spine, it causes severe curvature.

I know it especially impacts smallmouth and blue catfish (and apparently grass carp).

But I have no idea why it affects some species and not others?

 

[huntintn]

Dork fish.

 

[B.D.]

In hatchery-bred fish, it can be caused by a vitamin C deficiency in the feed that is fed to the fry. Since grass carp are mostly stocked, it's highly likely that this is what you're seeing. The batch of grass carp in the pond you're fishing was fed poor-quality feed at the hatchery.

bd

 

[FARMTOFIELD]

Dork fish.

Caught him on a corn dog

 

[SilverFox]

Heard about this with some smallmouth on Norris. Haven't seen it first-hand but several people I know have.

 

[geezer]

Cross breed with the camelfish maybe!!!

 

[stik]

I don't know if there is any relation or not but trout will get a condition that cause thier spine to twist...it causes them to swim around in circles...

whirling disease nothing to do with the spine.

 

[catman529]

In hatchery-bred fish, it can be caused by a vitamin C deficiency in the feed that is fed to the fry. Since grass carp are mostly stocked, it's highly likely that this is what you're seeing. The batch of grass carp in the pond you're fishing was fed poor-quality feed at the hatchery.

bd

Stocked grass carp must be triploid (sterile) by law in TN. These were stocked for weed control (obviously) yet the pond also is treated with chemicals to kill weeds and algae. I don't know where they get their food from but they grow up to 20 pounds.

There are more than one that are bent like this, and it could be from a deficiency since they were definitely raised at a hatchery. Most likely the hatchery from KY that comes down to Tractor Supply Co. But I am assuming that hatchery supplies most of the grass carp in this area, however most other places I have seen stocked grassies don't have any bent fish. could be coincidence, I don't know.

 

[TJS209]

I caught a large mouth bass this year like that

 

[JohnnyArcher]

Man, as if carp weren't ugly enough as it was!

 

[catman529]

Man, as if carp weren't ugly enough as it was!

grass carp aren't ugly, they look like a tarpon. it's just a plain silver fish

 

[stik]

Man, as if carp weren't ugly enough as it was!

grass carp aren't ugly, they look like a tarpon. it's just a plain silver fish

i don't think they look like a tarpon at all. skipjacks, however are tennessee tarpon. and yes, they are ugly too.

 

[shopson]

We catch occasional sauger and walleye like that too.

 

[catman529]

Man, as if carp weren't ugly enough as it was!

grass carp aren't ugly, they look like a tarpon. it's just a plain silver fish

i don't think they look like a tarpon at all. skipjacks, however are tennessee tarpon. and yes, they are ugly too.

come to think of it, skippies do look a lot more like a tarpon. And beauty is in the eye of the beholder... come to think of it, a lot of fish look ugly when you stare them down in the face. Except for sunfish, those are just pretty fish.

 

[B.D.]

Most likely the hatchery from KY that comes down to Tractor Supply Co. But I am assuming that hatchery supplies most of the grass carp in this area, however most other places I have seen stocked grassies don't have any bent fish. could be coincidence, I don't know.

The fish in the other ponds may not have come from the same "batch" in the hatchery. It only takes a short period of time for the vitamin deficiency to cause skeletal deformities if you feed bad food to the fry at the wrong time.

I was told that last year Dale Hollow hatchery lost a lot of brown trout because of a bad batch of feed. Unfortunately quality control isn't always so good with some of the cheaper feed manufacturers, and a lot of hatcheries buy from the low bidder.

bd

 

[Bowboy96]

It is most likely something from the Hatchery. Most of the grass carp I have caught in a pond have been like that. Its not good for the fish. But I guess they learn to live with it

 

[catman529]

Well if I had a lake and paid $10 per fish to stock grass carp, I would want replacements if they grew deformed spines like that...

 

[Football Hunter]

Man, as if carp weren't ugly enough as it was!

amen!

 

[Football Hunter]

Man, as if carp weren't ugly enough as it was!

grass carp aren't ugly, they look like a tarpon. it's just a plain silver fish

i don't think they look like a tarpon at all. skipjacks, however are tennessee tarpon. and yes, they are ugly too.

come to think of it, skippies do look a lot more like a tarpon. And beauty is in the eye of the beholder... come to think of it, a lot of fish look ugly when you stare them down in the face. Except for sunfish, those are just pretty fish.

Not smallmouth,beutifuless fish there is !

 

[catman529]

Man, as if carp weren't ugly enough as it was!

grass carp aren't ugly, they look like a tarpon. it's just a plain silver fish

i don't think they look like a tarpon at all. skipjacks, however are tennessee tarpon. and yes, they are ugly too.

come to think of it, skippies do look a lot more like a tarpon. And beauty is in the eye of the beholder... come to think of it, a lot of fish look ugly when you stare them down in the face. Except for sunfish, those are just pretty fish.

Not smallmouth,beutifuless fish there is !

I love smallies, nailed a few in the creek yesterday, I prefer them over largemouth just because of the fight. Pretty markings on them sometimes, but other than that, I don't see how a grass carp is much worse, they just look like fish to me.

 

[TTU Biologist]

SELENIUM! Scoliosis and kyphosis are two birth defects that are prominent in offspring of fish exposed to toxic quantities of selenium. Oftentimes, the difference between non-toxic and toxic levels is minuscule. Because some plants sequester selenium, it would make sense that grass carp are affected. For piscivorous species, selenium is passed up to them through the food chain.

Tomas

 

[catman529]

SELENIUM! Scoliosis and kyphosis are two birth defects that are prominent in offspring of fish exposed to toxic quantities of selenium. Oftentimes, the difference between non-toxic and toxic levels is minuscule. Because some plants sequester selenium, it would make sense that grass carp are affected. For piscivorous species, selenium is passed up to them through the food chain.

Tomas

Thank you, I bet that is the problem.

 

[B.D.]

Unless there is a source for selenium contamination for that one particular pond (coal burning plant, copper smelter, glass maker), I'm going to say that bad feed from the hatchery is far, far more likely to be your problem instead of selenium pollution.

Here's an easy test that I'm surprised TTU Biologist didn't mention - do other species of fish in the pond like bluegill, bass, and minnows also have scoliotic curvature? If so, then I'd be persuaded that your problem is water contamination.

But if all the fish in the pond are healthy except for the ones that were stocked from a hatchery what does that tell you?

bd

 

[catman529]

Unless there is a source for selenium contamination for that one particular pond (coal burning plant, copper smelter, glass maker), I'm going to say that bad feed from the hatchery is far, far more likely to be your problem instead of selenium pollution.

Here's an easy test that I'm surprised TTU Biologist didn't mention - do other species of fish in the pond like bluegill, bass, and minnows also have scoliotic curvature? If so, then I'd be persuaded that your problem is water contamination.

But if all the fish in the pond are healthy except for the ones that were stocked from a hatchery what does that tell you?

bd

You have a point... one bass I saw was tapered/skinny towards the tail but not scoliotic. I don't think I have seen anything other than the carp that were crooked. Catfish, bluegills, bass, and shellcracker seem to be healthy.

 

[Harold Money jr]

Believe it or not, Fish can and do develop scoliosis due to low oxygen levels when in larval form. I see it alot in catfish which are cavity spawners if the female doesn't keep the nest fanned the there could possibly be a deficiency in oxygen. Triploid Grass carp's eggs are put under tremendous pressure in a process to render them infertile. So it has always been a question to me how they even survive such treatment much less with a curved spine.

 

[B.D.]

You have a point... one bass I saw was tapered/skinny towards the tail but not scoliotic. I don't think I have seen anything other than the carp that were crooked. Catfish, bluegills, bass, and shellcracker seem to be healthy.

It is POSSIBLE that plants in the pond could accumulate selenium and thus the plant-eating grass carp would be disproportionately affected. I tend to doubt that though.

Phytoplankton is known to accumulate selenium, and it travels up the food chain. Bugs and small fish eat the phytoplankton, and then those bugs and small fish are food for the catfish, bluegill, bass, and shellcracker in the pond. Thus, if selenium is in the pond, you should see it concentrated in the fish at the top of the food chain.

That's why I'm betting on it being a case of grass carp being fed cheap, vitamin deficient feed at the hatchery.

bd

 

[ol 'rube]

maybe hes been eating too much sewer water

 

[mountain man 71]

Never seen that before.