While fishing Lake Pepin my wife and I caught a couple small saugers that had a really weird looking back on them. Almost a S shape to the spine. I also seen others with photos of the same thing. Has there been any research as to why this is happening? 50 years of fishing and I have never seen this before.
i have not caught one like that yet
They look like this
Funny you ask that…not because I have an answer but did catch a 4-5 pound northern the other day trolling on a lake outside of St. Cloud and the fish had the same “s” like shape. The only thing I could think of that possibly this fish had a spear thrown at it, broke its spine and never healed right…..as far as the saugers, you got me.
I would think this type of injury happens in the first few days or weeks after hatching. What actually causes it? No idea.
There was a similiar post on this forum a while back and reply that the condition was caused from lack of nutrition. Hard to beleive on p4.
I’m not buying a lack of nutrition for a pool 4 fish.
A quick look around the web found this info as possible causes:
Lack of Vitamin C – this shows up especially in hatchery raised fish but could happen to wild fish, too, if they have a very poor diet
Injury when young – an injury to the backbone of a young fish could cause them to grow with a curved or deformed spine if the injury is not too severe.
Birth defects – much like people, fish can hatch from the egg with a defect in the spine that causes the curved spine. If it is geneteic, it can be passed on to their offspring.
Severe changes in temperature while in the egg – if there are severe water temperature changes after the eggs are laid it can cause this deformity. This happens more often in hatchery raised fish but can happen in the wild.
Parasites – there is some evidence parasites are cauging deformities in young northern pike in an Oregon study of the Newberg Pool of the Willamette River
Article on deformed fish from Environmental Contamination and Toxicology
Abstract Smallmouth bass (Micropterus dolomieui) populations in two of five reservoirs sampled in the southern Appalachian Mountains contained high percentages of individuals with lordosis, kyphosis, or scoliosis. Deformities of the vertebral column occurred in several year classes and varied with fish size; they were absent in small fish, present in 25–30% of the fish 241–300 mm long, and then decreased in occurrence with increased length. Because environmental contamination is often responsible for high occurrences of deformed fish, whole-body concentrations of contaminants, bone development characteristics, and blood plasma concentrations of calcium and phosphorus in normal and deformed fish were measured and compared the results with those for fish from reservoirs where no deformities were found. Vertebrae were significantly weaker and more elastic in deformed than in normal fish, but biochemical properties of vertebrae were similar among the groups tested. Concentrations of pesticides and metals were not elevated in deformed fish, and concentrations of calcium and phosphorus in blood plasma were similar in normal and deformed groups. Most environmental contaminants that have been shown to cause fish deformities could be discounted as causative agents on the basis of these results; however, the exact cause was not determined. Further attempts to diagnose the cause of the deformities were limited by the lack of background information on relationships among bone development processes, types of stresses that cause deformities, and types of bone tissue in fish.
The Unit is jointly sponsored by the U.S. Fish and Wildlife Service, the University of Georgia, the Georgia Department of Natural Resources, and the Wildlife Management Institute.
By Carol Savonen, 541-737-3380
SOURCE: Larry Curtis, 541-737-1764
CORVALLIS – After the first year of a two-year study, Oregon State University scientists have found about three times as many juvenile minnows with backbone deformities in the Newberg Pool of the Willamette River than at a site 80 miles upstream near Corvallis.
Larry R. Curtis, an OSU professor of environmental toxicology, will present preliminary results of a Oregon Watershed Enhancement Board-funded study on pike minnow fish deformities in the Willamette River to the Oregon Legislative Emergency Board in Salem this Thursday (Jan. 9).
OSU researcher Gene Johnson and doctoral student Doolalai Sethajintanin clean samplers just pulled from the Willamette River.
Click on image to go to downloadable photo
For years, the Newberg Pool of the Willamette, just south of Portland, has been a notorious place for finding a high percentage of young fish with skeletal deformities.
“There’s significant public concern over deformed fish in the Newberg Pool of the Willamette River, but little scientific basis for explaining the deformities,” said Curtis, head of the OSU Department of Environmental and Molecular Toxicology. “These fish are sentinels for environmental contamination. People want to know what’s causing the deformities and whether they have any implications for human health.”
As the lead investigator of OSU’s interdisciplinary study of the Willamette River and its deformed fish, Curtis has gathered together OSU’s Agricultural Experiment Station toxicologists, chemists, microbiologists and fisheries biologists in an effort to determine the prevalence of skeletal deformities in juvenile fish in stretches of the Willamette River near Newberg and Corvallis.
The OSU researchers also are trying to determine what causes these deformities. They are comparing the physical and chemical conditions and the accumulated toxicants in ovaries of fish from adult northern pike minnows at Corvallis and Newberg and conducting laboratory studies that might show a link between physical or chemical conditions in the river and the incidence of deformities.
OSU researcher Bobby Loper, doctoral student Doolalai Sethajintanin , bioresource research student Solyssa Visalli and Keaboletse Kgokong (visiting faculty from Botswana) test underwater equipment at Corvallis on the Willamette River.
Click on image to go to downloadable photo
OSU researchers in the Department of Fisheries and Wildlife and the Department of Microbiology have examined the deformities and found tiny parasites associated with some of the deformed fish. The suspected parasite is a microscopic myxozoan in the genus Myxobolus, a relative of the microorganism that causes whirling disease in salmon.
There are no human health threats associated with this fish parasite, said Curtis.
So far, the researchers have found most of the physical and chemical characteristics of the water at Newberg and Corvallis to be similar. Temperature, pH, dissolved oxygen and nitrate levels did not vary significantly between the two sites.
The investigators detected similar low concentrations of heavy metals cadmium, copper, lead and zinc at both sites, although they found one high zinc sample measured in the Newberg Pool. They found concentrations of persistent organic contaminants including dieldrin, DDT, DDD and DDE to be two to four times higher in Newberg Pool than Corvallis, but all detections were extremely low, below one part per trillion, said Curtis.
They haven’t yet completed analyses for other chemical classes, including currently used pesticides. The researchers are now measuring persistent bioaccumulative toxicants in ovaries collected from adult pike minnows in both sites on the river. Results are not yet available.
In recent experiments, newly fertilized eggs were exposed to river water from each site for 15 to 47 days. They didn’t detect any differences in development between fish reared in water from either location.
The scientists have another field season, spring through the fall of 2003, to collect data and fish and study both sites on the Willamette. They will also conduct more laboratory experiments on zebrafish with various concentrations and fractionations of toxic materials from the river water from each site. The final report will come out in 2004.
On pool 11, we call that sauger scoliosis 
The weird thing is, I’ve never caught a walleye like that, only saugers. But it doesn’t seem to be that rare. I was thinking that being I’ve only seen it on saugers, it may be genetic, I don’t know, but it sure is goofy looking.
Yes that picture was from someone elses post a couple weeks back. They were to small to keep so I wonder if I should have just knocked it over the head.
Thanks for the info James.
I’ve caught three sauger like that this year and I don’t get out fishing that often. I have only seen the deformity in saugers as well and only in roughly 10″ fish. Although, they are tough to measure without a curvy tape… 
My vote goes to injury while juvenile. More saugers=more injury on each other. Good info James, thanks for the research!
FWIW…I did catch an 18″ walleye on Pool 4 Monday that had the deformed back. Gregory
I’ve kept a lot of diff fish in my days that have paired off/spawned. In a closed environment (aquariums) that deformity is always common if its my understanding from these experiences it’s from lack of nutrients/oxygen/Ecosystem… bla bla bla (stunting) It can happen at anytime before maturity. Fish deformed that bad are lucky to make it that big.
By being lucky to make it that big, do you assume the genetic defect or whatever it is will eventually kill the fish? Because I have caught many of these fish on P4, and they attacked a jig, ringworm, lure pulled on lead and three way with as much gusto as any other walleye/sauger in its year class. Although genetically “off” and without a doubt unpleasing to the eye; I dont believe there is too detrimental an effect on the survival rate for the fish. Only time will tell! Might be good to bring all this up to a fisheries biologist in the area, would be neat to see one of those studies done here on P4. 
We caught a 19″ curved walleye last saturday. I think its the only walleye that Ive caught with the curve. But Ive seen at least 20 saugers that look like that. None over 15in though. Seem to catch more with the defect in the lake than in the river. Only a few up in the river this year. Id sure like to know what is really causing it. I too agree with they give as much resistance as a normal fish of equal size.
Caught one on pool 2 a week ago…sauger.
JP
We caught 3 small saugers or one sauger three times last weekend on Pepin with this curved back. Let it go but wondered if we should get it out of the gene pool so to speak??? Any ideas,
I don’t believe it is a gene situation, and even if it was, a mutation does not constantly repeat itself. The only thing that leads to speciation is isolation. Has to be either injury, nutrition, or something else that no one wants to hear.
The first one I saw I figured it was from a injury, but then after seeing more then one why would they all look the same? Unless that’s the weakest link while they were young. Maybe it’s not a big concern but maybe it is.
I wonder if small fish get damaged by going thru the dam or the power plant. I would imagine the currents are tremoudous at times. For that to be true,…it would have to occur in all pools I suppose.
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