# Saugeye Vs Sauger



## Mushijobah

I really wish there was an in depth comparison chart between the two.....Even at the OEPA, I have not heard a straight answer on the physical difference between the two. Have any of you guys seen such a comparison that has proved accurate?

Also, please spare me your personal descriptions if they involve a white tip on the tail (many medium sized saugeye lack it), Girth (many medium sized saugeye have the identical girth to a nice sauger), or spotted/barred fins (either can have).


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## JamesT

The secret is in the dorsal fin membrane. The pigment and pigment expression is different between a saugeye and sauger. The gene that controls this pigment is dominant in female walleye and almost always gets passed on to the offspring. I don't have any up close pics of the dorsal fin membrane, but if you look closely you will tell. Saugeye have a darker pigmentation when compared to a sauger from the same water conditions. If the fish are highly stressed, such as after catching them, sauger may exhibit some different pigment shades but it will still not be as dark as the saugeye.


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## riverKing

if it has deffinant round or oval spots on the dorsal than it is a sauger
saugeye do not have the well defind spots they have bars, other than the blotches they get on the side in clear water they look alot more like walleye than sauger. again, spots on the dorsal its a sauger. 
they really are not that difficult to tell apart its just that most people are clueless and say they are all saugeye because thats what they catch in the lakes. also, if you are in a river that runs into the ohio, its almost always a sauger, there are more 18+in sauger in the rivers that i fish than there are saugeye people just assume that the fish are saugeye from size


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## Mushijobah

I mean, like I have said, the fin markings do not tell the difference. Go catch a 16" 'eye' in the Scioto below greenlawn and try to honestly tell me which one it is. Not happening with your hypothesis.


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## fishslim

It's a saugeye!!


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## riverKing

its how i tell the difference on the shocking boats in the ohio river doing the population survey's, and its not a hypothesis. the saugeye in the hocking river, the muskingum river, the lmr and the gmr as well as the ohio, dont have the major spots on the dorsal. its like jamesT mentioned, it has to do with the te gene carried by the female walleye, now maybe every once in a while saugeye get faint spots but the ones i have seen have shaded bars behind each of the dorsal spines. if i am ever below greenlawn and i catch a 16in eye i will be able to tell you the difference by looking at the fin markings


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## fishslime

Here is the two side by side saugeye on bottom


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## Daveo76

Great picture fishslime. That's the way we tell them apart here at the river. Saugers will generally will have the spots on the fin in generally straight lines and saugeyes have them more scattered if they have them. Great comparison shot again!


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## JamesT

Get some glasses. And look more closely at the dorsal. If you want to be so scientific (which I think you do) get an internship at a breeding facility and look at 1000 saugeye and sauger. Look at the dorsal fins and do a t-test. Statistics will prove the dorsal fin theory right.

Yes you have said what you don't want to hear and don't believe, but you haven't shown any proof. If you want scientific answers, prove to me that the theories you disbarred in your first post are not true. How many times have you had both known sauger and saugeye in a statistically valid population to compare your theories against. My guess is zero.



Mushijobah said:


> I mean, like I have said, the fin markings do not tell the difference. Go catch a 16" 'eye' in the Scioto below greenlawn and try to honestly tell me which one it is. Not happening with your hypothesis.


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## riverKing

that pic needs to be posted as a sticky so everyone can see exactly how to tell the difference, awesome pic


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## Mushijobah

My HYPOTHESIS, (not theory, please look up the definition for that) is that dorsal markings do NOT decipher the species or hybridization of the sauger and sauger/eye. I WORK ON A SHOCK BOAT IN THE SUMMER FOR THE OEPA. Different scientists have told me different things on identifying the fish, I just do not know who to believe. The fish I primarily catch in Alum Creek have only spots, yet there are low head dams preventing their migration to those areas. Therefore, any logical hypothesis would say they were SAUGEYE. I also have electro-shock reports from Alum that were done by two different scientists at two different times (1996 and 2000) that show similar numbers of SAUG fish, but one identified them as SAUGER, and one SAUGEYE. Obviously to the scientific community this is still unclear...that is the only reason I am asking. That picture I saw above...would make every single eye I have caught from Alum a sauger when I know that is not true.


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## Mushijobah

Check this out also....

"How can you identify a saugeye from a walleye or a sauger? Since saugers are primarily found in the Ohio River, the identification problem most likely to occur is between the saugeye and walleye."

LAST PARAGRAPH OF http://www.dnr.state.oh.us/wildlife/Feature/FishF/saugeye.htm

That is simply untrue that they are primarily found in the OR. And everyone knows the main identification problem would be between a sauger and saugeye. It just sounds like the ODNR is trying to persuade the public that they would be stupid to even question the actual genetic makeup of their 'saug' fish because it is obviously a _______. Every minorly educated fisherman knows the difference between a walleye and a saugeye, it is just sad that they can actually spew out such a crappy lie and assume people would believe it. The bottom line is no one has provided me with documented proof online (which shouldn't be rare seeing that everything is online these days) that can easily decipher a sauger from a saugeye. 

Keep looking !


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## misfit

my THEORY is that since you've formed your own HYPOTHESIS,and have rejected the HYPOTHESES of several scientists,including ones from the epa and dnr,that any supposed "documented" proof offered in this forum would most likely be subject to your scrutiny also


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## Lewis

I know its not Saugeye versus Sauger,but here are a couple interesting reads on how even trained hatchery personell make mistakes in identification..


http://www.ohiogamefishing.com/community/showthread.php?t=21219&highlight=saugeye+identification

http://www.ohiogamefishing.com/community/showthread.php?t=20229&highlight=saugeye+identification


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## Mushijobah

I just wish someone could come up with a writeup published by an acclaimed institution that lays the rules down. It just seems that the traits passed are just variable making identification close to impossible on some specimens.


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## JamesT

Mush-
Just curious - why do you wish this? Why do there need to be further rules. The dorsal fin membrane markings will account for 99% of good IDs. Show me a picture of what you believe to be a saugeye that does not have these characteristic markings...

What speciments are impossible to identify??Please provide pictures.

I'm trying to understand where you are going with this...

And what are five examples of "acclaimed institutions" whose answer you are willing to accept?

James



Mushijobah said:


> I just wish someone could come up with a writeup published by an acclaimed institution that lays the rules down. It just seems that the traits passed are just variable making identification close to impossible on some specimens.


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## JamesT

Mushijobah said:


> My HYPOTHESIS, (not theory, please look up the definition for that) is that dorsal markings do NOT decipher the species or hybridization of the sauger and sauger/eye. I WORK ON A SHOCK BOAT IN THE SUMMER FOR THE OEPA. Different scientists have told me different things on identifying the fish, I just do not know who to believe. The fish I primarily catch in Alum Creek have only spots, yet there are low head dams preventing their migration to those areas. Therefore, any logical hypothesis would say they were SAUGEYE. I also have electro-shock reports from Alum that were done by two different scientists at two different times (1996 and 2000) that show similar numbers of SAUG fish, but one identified them as SAUGER, and one SAUGEYE. Obviously to the scientific community this is still unclear...that is the only reason I am asking. That picture I saw above...would make every single eye I have caught from Alum a sauger when I know that is not true.


Let's look at your hypotheis step by step.

"Different scientists have told me different things on identifying the fish, I just do not know who to believe."
It is good to be skeptical of scientists -they are not always rights, nor do they always pass on accurate or complete information.

"I WORK ON A SHOCK BOAT IN THE SUMMER FOR THE OEPA."
So what. 

"Different scientists have told me different things on identifying the fish, I just do not know who to believe."
Make up your own mind. Please clarify the names of the scientists and what they have told you. I know most of Ohio's marine biologists both working for the state, academia and other research institutions. I may be able to provide you with some insight if you can give better details about who told 
you what.


"The fish I primarily catch in Alum Creek have only spots, yet there are low head dams preventing their migration to those areas. Therefore, any logical hypothesis would say they were SAUGEYE."
Flooding can allow for 2 way migration. There is no logical hypothesis there.

"I also have electro-shock reports from Alum that were done by two different scientists at two different times (1996 and 2000) that show similar numbers of SAUG fish, but one identified them as SAUGER, and one SAUGEYE."
Either one of the scientists misidentified the fish or made a simple, clerical error on the report, or there was a significant population shift over a 4 year period. Can you forward the electroshock results to me? I'd be curious to know more information about sizes of the fish and locations of the shock.

"Obviously to the scientific community this is still unclear...that is the only reason I am asking. " 
You have referenced very few scientists in making your conclusion that the "community" is unclear about this. The "community" will tell you to look at the dorsal fin membrane as there is sound scientific evidence that the female walleye possesses a dominant gene for these markings that gets passed on to a very high percentage of saugeye. Yes, genetics are not always 100%. If you need 100% accuracy you need to take my class at OSU on marine genetics.


"That picture I saw above...would make every single eye I have caught from Alum a sauger when I know that is not true"
Are you sure - how do you know that is not true. Please post pictures of the fish you are claimaing to be saugeye and not sauger. I'm not sure how you can say "I know that is not true" if you posted on not knowing how to tell the difference between the 2???

Let's get this settled, as I don't want you to be confused any more than you are...I'm here to help.

Prof. James


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## Mushijobah

Prof.,

Like I have asked..show me a write-up stating the difference from an acclaimed institution. Replying to your replies would simply be a waste of time, although the task would not prove difficult...just the time. You have provided nothing so far worth a damn! If you cannot provide me with what I asked originally, why are you still posting? Flaunting your E-cock-a-doodle-doo will only get you so far, and with this thread, it gets you no where.

You seem like a smart guy who has his facts together, only if you could find a bit of documentation!


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## Mushijobah

Ah and for the proof/shock stats you asked for, Mr. James.

1986 Report shows:

Saugeye: 1
Sauger: 0
captured between RM .8 and RM 7.5. This is believeable seeing the condition of the stream at that time was much worse than the latter years.

1996 Report shows:

Saugeye: 21
Sauger: 4

Captured between RM's .8 and 9.2. Interesting catches include 3 Muskies from a secret location in that stretch...Averaging 14 LBS. 

2000 Report shows:

Saugeye: 2
Sauger: *52*



That sounds a little 'fishy' to me. I also know both scientists who shocked each year...And know for a fact that they have differing views on Saug identification. The DNR is also like this. It is not uncommon for even the pros to get the fish mixed up. 

If you would like to get these shock reports yourself, please contact the OEPA just like I did...or you could paypal me some money to copy/send them to you


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## JamesT

Please reply to what I had to say. You appear to know squat about science and statistics. Real science is difficult. There are so many posers that have some scientific skill, but as I stated, there was obviously a mixup or a case of someone not knowing what they were doing.

Send me some money and I will provide you with a report. You have already dismissed the definition by ODNR - I'm not sure what qualifies you to do such?

If ODNR is not an acclaimed institution, what are you looking for? A peer reviewed scientific journal? 

Read this:
Billington, N., R. C. Brooks and R. C. Heidinger. 1997. Frequency and natural hybridization between saugers and walleyes in the
Peoria Pool of the Illinois River, as determined by morphological and electrophoretic criteria. North American Journal of Fisheries
Management 17: 220-224.

You will learn that up to 3% the fish you question are actually triploid hydrids and may not experience the dominant female gene. As I said, genetics is not 100%.

Your shock reports tells the whole story - the two different guys that did the tests had differing views on ID - THUS THE DIFFERING RESULTS...Sounds like one of "scientists" has a personal agenda, which is common amongst reputed scientists.

Now go study. Read this while you are at it:
Trautman, M. B. 1981. The fishes of Ohio (2nd edition). The Ohio State University Press. Columbus, Ohio, USA.

As for wasting time - you are lucky I am educating you! But as an academic servant, I feel blessed to be able to offer my services. If you think I have provided nothing worth a damn, you are not reading. And obviously understand ZERO about genetics. Go read a book. Working for a summer on an electroshocking outfit is a start, but you have many years before you are as smart as you think you are....

As you my E Cock a Doodle Do - you are only showing your immaturity. Grow up and learn something. I don't need to get anywhere on this thread - I'm trying to help you.

Recess is over - go study your genetics!




Mushijobah said:


> Prof.,
> 
> Like I have asked..show me a write-up stating the difference from an acclaimed institution. Replying to your replies would simply be a waste of time, although the task would not prove difficult...just the time. You have provided nothing so far worth a damn! If you cannot provide me with what I asked originally, why are you still posting? Flaunting your E-cock-a-doodle-doo will only get you so far, and with this thread, it gets you no where.
> 
> You seem like a smart guy who has his facts together, only if you could find a bit of documentation!


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## Mushijobah

The DNR is a division that is for the Saugeye. The Saugeye makes a lot of money for the DNR. They would never publicly say that there may be difficulty identifying a sauger from a saugeye because it would put their so-called 'sterile' fish in jeapordy. The DNR has a personal agenda, like you mentioned about certain scientists, to keep the saugeye program up and running when in reality saugeye are polluting the gene pool of native sauger and walleye. If you do not believe that, read this.

http://in.gov/dnr/fishwild/publications/notes/Ohio&#37;20River Percid Investigation Final Report.pdf

I believe the good stuff starts on page 7-8 (although I reccomend it all). It describes the interbreeding of native sauger/walleye and stocked saugeye resulting in FISH DISPLAYING DIFFERENT PHENOTYPES! So yes, a 'sauger' could have a barred dorsal and a saugeye could have a spotted one! These fish are in no way sterile, and can display similar traits when belonging to a seperate species. There is is right there, take it or leave it Prof.!

As far a Trautman goes...the book was written before the word saugeye was even concieved. Duh! It is mentioned nowhere in the text, and only in the section that reccomends hybrid possibilities. This serves true with every other species in the book too.

Who says I said I was smart? I simply mentioned that an identical looking fish that could have bars or spots so far cannot be identified easily other than by size when fully grown. All I asked for something published that described the two fish. I doubt the ODNR even has this. Link it if you ever find it...that is what this thread was about in the first place.


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## Mushijobah

I have begun emailing a few acclaimed people around the state to get their opinions. I will see if they have taken the same impression as you have on identifying saugeyes as you have. Hopefully they will provide something writtern because it seems so hard for anyone to do it on here!


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## JamesT

Of course I believe that saugeye pollute the native gene pool. Read my posts to figure that out. Never said anything about them being sterile...And there you have your answer - if you are catching fish that you cannot identify as saugeye or sauger - then you have caught another hydrid displaying different phenotypes...I think you answered your own question...

BUT:"So yes, a 'sauger' could have a barred dorsal "
THIS IS NOT TRUE. A sauger bred to a saugeye could display this - but then it is NOT A SAUGER. It is now a hybrid. 

So, should I "Take it or leave it" - I'll take it - you've just answered your own question and supported what I've been saying.

I wasn't referring to Trautman to learn about Saugeye - Trautman (which I presume you have read) is an intermediate (in terms of marine biology history) read that should give you some insight on how the thought process of marine biologists have changed over the last 30-40 years.

Did you read the Illinois paper I referred you to? My guess is the Indiana group references it...

As for your question - you asked about SAUGEYE AND SAUGER and THEIR IDENTIFICATION - NOT ABOUT THE IDENTIFICATION OF OTHER HYBRIDS.\

Cya.

Mush - you sound like you'd be a good guy to fish with. You want to go wet a line together?



Mushijobah said:


> The DNR is a division that is for the Saugeye. The Saugeye makes a lot of money for the DNR. They would never publicly say that there may be difficulty identifying a sauger from a saugeye because it would put their so-called 'sterile' fish in jeapordy. The DNR has a personal agenda, like you mentioned about certain scientists, to keep the saugeye program up and running when in reality saugeye are polluting the gene pool of native sauger and walleye. If you do not believe that, read this.
> 
> http://in.gov/dnr/fishwild/publications/notes/Ohio River Percid Investigation Final Report.pdf
> 
> I believe the good stuff starts on page 7-8 (although I reccomend it all). It describes the interbreeding of native sauger/walleye and stocked saugeye resulting in FISH DISPLAYING DIFFERENT PHENOTYPES! So yes, a 'sauger' could have a barred dorsal and a saugeye could have a spotted one! These fish are in no way sterile, and can display similar traits when belonging to a seperate species. There is is right there, take it or leave it Prof.!
> 
> As far a Trautman goes...the book was written before the word saugeye was even concieved. Duh! It is mentioned nowhere in the text, and only in the section that reccomends hybrid possibilities. This serves true with every other species in the book too.
> 
> Who says I said I was smart? I simply mentioned that an identical looking fish that could have bars or spots so far cannot be identified easily other than by size when fully grown. All I asked for something published that described the two fish. I doubt the ODNR even has this. Link it if you ever find it...that is what this thread was about in the first place.


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## Mushijobah

I guess most fish I catch then are saugeye after thinking about it in those terms. Even if there is a slight genetic difference from a full blooded sauger...it is still a hybrid.

PS I would love to wet a line..it's good to be able to be out there with someone who also has a passion for aquatic/stream ecology apart from the ones only focused on the fishing aspect. Where do you frequent?


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## JamesT

Quite possibly. It is also possible that the scientist who claimed a high population of sauger made his/her mistake on purpose.. 

Whether it is animals, plants, fish, etc...I hate to say "heirloom" or "native" gene pools disappear. Unfortunately this saugeye introduction may be doing just that...

I mainly fish Scioto and RARELY (as in twice) see a true sauger...



Mushijobah said:


> I guess most fish I catch then are saugeye after thinking about it in those terms. Even if there is a slight genetic difference from a full blooded sauger...it is still a hybrid.
> 
> PS I would love to wet a line..it's good to be able to be out there with someone who also has a passion for aquatic/stream ecology apart from the ones only focused on the fishing aspect. Where do you frequent?


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## Mushijobah

I will definately snap a few shots of the next ones I catch from Alum. Their dorsal markings are much less blotchy than the saugeye I get below greenalwn, and further south. Oval like almost. These fish are extremely slender too. I usually catch around 5 or so each time out, but they rarely go above 15". Perhaps I am using the wrong bait for the big boys, I don't know, but I will take pictures.


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## fishing_marshall

Mushijobah said:


> The DNR is a division that is for the Saugeye. The Saugeye makes a lot of money for the DNR. They would never publicly say that there may be difficulty identifying a sauger from a saugeye because it would put their so-called 'sterile' fish in jeapordy. The DNR has a personal agenda, like you mentioned about certain scientists, to keep the saugeye program up and running when in reality saugeye are polluting the gene pool of native sauger and walleye. If you do not believe that, read this.
> 
> http://in.gov/dnr/fishwild/publications/notes/Ohio River Percid Investigation Final Report.pdf


Thats some good reading


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## Lewis

Slightly off topic,but still a very interesting read regarding Saugeye/Walleye.
Thanks Corey!!

Habitat Preferences, Survival, Growth, Foods, and Harvest of Walleye and Walleye X Sauger Hybrids
Abstract.- We compared habitat preferences, survival, growth, foods, and harvests of stocked Walleyes Stizostedion vitreum and Walleye X Sauger S canadense hybrids in Pleasant Hill Reservoir, Ohio. Both fishes were stocked at similar rates and sizes (about 40mm mean total length) in late May or early June 1979-1982. Neither group showed consistently better survival. Growth was similar until age 2. Thereafter, hybrids grew faster than Walleyes. Age-0 Walleyes occured mostly over fine substrates in early Summer and coarse substrates by Fall. Habitat selection by age-0 hybrids was similar to that of Walleyes, except hybrids preferred finer substrates in Fall. Older hybrids and Walleyes moved offshore at temperatures above 22 degrees C. Diets of both fishes were similar, but hybrids ate more littoral fishes, where Walleyes ate more pelagic fishes. Age-1 and older hybrids and Walleyes ate mostly invertebrates in Spring. Age-0 Gizzard Shad (Dorosoma cepedianum) were the most important prey for all age of both groups. Hybrids and Walleyes were caught by anglers in proportion to their abundance and contributed most to the fishery at ages 1 and 2. Hybrids have the potential to breed with either parent species and may introduce new genetic material into existing Walleye or Sauger populations. Data from our study and other Ohio waters show that hybrids can support important fisheries, particularly in tailwaters, and may be more successful than Walleyes in impoundments with short water-retention times.


Walleyes, Stizostedion vitreum are highly desirable gamefish, but in many waters they do not reproduce (Laarman 1978; Prentice and Clark 1978). Consequently, many Walleye management programs rely heavily on stockings to maintain populations. The need for large numbers of juvenile fish for stocking has stimulated the search for more efficient hatchery production. A Walleye hybrid (Walleye X Sauger S. canadense, commonly known as Saugeye) showed consistently better growth and survival than Walleyes in rearing ponds at the Senecaville National Fish Hatchery, Senecaville, Ohio (J. Hawkinson, Senecaville National Fish Hatchery, personal communication). In 1978, the survival and growth of juvenile hybrids stocked into Deer Creek Lake, Ohio was greater than that of Walleyes in most Ohio waters (R. Schaefer, Ohio Division of Wildlife, personal communication). Rapid growth and high survival of hybrids in both the hatchery and the reservoir suggested that hybrids might be more economical than Walleyes to raise for stocking. 
Literature on the biology of Walleye X Sauger hybrids is sparse. Natural hybrids occur rarely (Nelson and Walburg 1977; Billington et al. 1988) and were first identified in 1943 in Norris Reservoir, Tennessee, where their growth rate appeared to be intermediate between those of the parent species (Stroud 1948). Hybrids are fertile (Hearn 1986) and have been stocked successfully in Ohio ponds (Lynch et al. 1982) and in Cherokee Reservoir, Tennessee (Humphreys et al. 1987).
Before feasibility of stocking hybrids as an alternative to Walleyes can be assessed, more information is needed on the biology of hybrids, especially in comparison with Walleyes. Our objectives were to compare habitat preference, survival, growth, foods, and harvest of hybrids and Walleyes stocked in a reservoir.


Study Area
The study was conducted from 1979 to 1982 in Pleasant Hill Reservoir, a eutrophic, 344 hectare reservoir in Northwestern Ohio. Maximum depth was 13m and mean depth was 5m. The reservoir was thermally stratified at a depth of 4-5m during June through early September. Temperatures in the epilimnion ranged from 20-24 degrees C. and the hypolimnion was anoxic. Midlake secchi disk transparencies usually ranged from 1 to 2 m but were lower (minimum, 0.36m) during flooding. Inshore transparencies were not measured regularly, but were generally lower than midlake readings and were directly related to substrate particle size. 
The Ohio Division of Wildlife has stocked Walleyes periodically in Pleasant Hill Reservoir since 1950. No natural reproductiuon of Walleyes has been documented since 1969. During 1976-1978, Walleyes of 44-75mm total length (TL) were stocked annually at a rate of about 35 fish/hectare. The reservoir also contains reproducing populations of Largemouth Bass Micropterus salmoides, Smallmouth Bass M. dolomieui, White Bass Morone chrysops, White Crappie Pomoxis annularis, and a variety of nongame species, of which Gizzard Shad Dorosoma cepedianum and Brook Silverside Labidesthes sicculus are most numerous. Muskellunge Esox masquinongy immigrate into the reservoir from a stocked population upstream.


Methods

Juvenile Walleyes and hybrids were stocked into Pleasant Hill Reservoir annually during late May or early June 1979-1982. Except in 1980, all fish were obtained from the Senecaville National Fish Hatchery, and both hybrids and Walleyes were stocked at a rate of 73 fish/hectare. In 1980, flooding delayed stocking by 1 week , during which time mortality at the hatchery was high. The surviving 17,000 Walleyes and 750 hybrids were supplemented with 10,000 hybrids from the London (Ohio) Fish Hatchery of the Ohio Division of Wildlife. The supplemental hybrids had been used in experiments with dry diets and were emaciated. In 1980, stocking rates were 49 Walleye and 31 hybrids per hectare.
Fish sampling.-Sampling began within 1 week after stocking and was conducted at least twice monthly through September. We used a bag seine (11m x 1.8m, with 5-mm-bar mesh) during the day in June and July and electrofishing (pulsed DC) at night from August through September. We categorized inshore habitats acccording to slope, wave exposure, and substrate. The open-water limnetic habitat was not sampled. To determine inshore habitat preferences, we sampled at least once each month at three to four standard stations in each habitat type. We used catch per unit effort (CPE) as a comparative measure of habitat preference. We could not use seines effectively for sampling exposed rock or steep rock areas; thus habitat preference analysis for June and July were were restricted to muck, clay-sand, and protected rock habitats. Because of delayed stockings in 1980, sample sizes of hybrids were small and these data were not included in in habitat analyses. Because there were only one or two samples per month, we combined data for 1979, 1981, and 1982 and tested for differences in habitat use (two-way analysis of variance, ANOVA) between age-0 hybrids and Walleyes within each month and between months (June and July or August and September) for each type of fish. Data were transformed as (X + 0.5)1/2 to normalize variance. 
We estimated population sizes of young-of-year hybrids and Walleyes in October of each year. Fish were captured at night by electrofishing and marked with a pelvic fin clip. In 1981 and 1982, we recaptured enough fish (>25) of both groups to enable us to use the Schnabel Formula (Ricker 1975). Recapture of Walleyes in 1979 and of hybrids in 1980 were too low to permit use of this formula. However, relatively precise estimates were obtained for the other group in each year. Because the ratio of age-0 Walleyes to hybrids was nearly constant on each night we sampled (four nights in 1979 and six nights in 1980), we based estimates of young-of-year Walleyes in 1979, and of hybrids in 1980, on their proportion in the total catch. A similar procedure was followed in 1980 for estimating hybrid numbers.
All captured hybrids and Walleyes were measured (TL) and weighed, except during for population estimates when a subsample of each group was weighed. We collected additional length and weight data from age-1 and older fish collected by electrofishing or fyke netting in April 1980-1983. Scale samples were taken from all fish longer than 350mm to determine age. Ages of fish less than 350mm were determined by length. 
Diet analysis.-Subsamples (maximun of 10/site.d) of age-0 hybrids and Walleyes were preserved in 10% formalin for stomach content analysis. Stomachs of older fish were preserved in formalin. Stomach contents were identified to species for fish and to family for invertebrates. We measured total length of intact fish taken from stomachs. Many Gizzard Shad were partially digested and impossible to measure, so we used a procedure similar to that of Knight et al. (1948) and measured either standard length (SL) or backbone length (BL). Total length was then estimated from equations derived from measurements of 180 preserved Gizzard Shad, 31-142mm TL.
Creel survey.-We conducted stratified, random creel surveys during April through September 1980-1982. Survey effort varied among years. In 1980, efort was 24 h/week and surveys were conducted on two weekdays and one weekend day (randomly selected), except in April and September when effort was 16 h/week and we surveyed on only one weekday. On each sampling day, the survey was conducted during a randomly selected 8-h period in either morning (0600-1400 hours) or evening (1400-2200 hours). A roving creel clerk counted all anglers on the lake every 2h. In 1981, effort was increased to 40 h/week and we surveyed on both weekend days. In 1982, effort was reduced to 30 h/week and was reapportioned to apply more effort during periods of highest variance. Thus a survey day was lengthened to 10 h and we again surveyed both weekend days.
Shore and boat anglers were interviewed between counts and all harvested game fish were measured. Hybrids and Walleyes less than 350mm were assigned to age classes based on length.Ages of larger fish were based on scales.
The tailwater pool below Pleasant Hill Dam is small (0.26 hectares) and subject to flooding, but does receive moderate fishing pressure under normal water conditions. In 1980 and 1982, tailwater surveys were integrated into the normal procedures for counts and interviews at the reservoir. In 1981, flooding prevented fishing in the tailwater for most of May and June; thus we did not survey the tailwater in that year.
In 1983, the Ohio Division of Wildlife conducted a creel survey on Pleasant Hill Reservoir from April through june (creel data from 1980 to 1982 showed that most Walleyes and hybrids were harvested during toose months). Effort was 20 h/week and included at least one weekend day. The tailwater was not surveyed. Count and interview procedures were similar to those in previous years, and scales were taken from all hybrids and Walleyes for age determinations.


Results
Habitat Preference

During June and July, hybrids and Walleyes were most frequently collected in inshore habitats with fine substrates. Habitat preferences did not differ between hybrids and Walleyes in June or July (P>0.2) but were significantly different in August and September (P<0.001), when hybrids were more common than Walleyes over fine substrates and Walleyes were taken mostly in exposed rock or steep rock habitats. There were no differences in habitat selection for either group between June and July (P>0.2) or between August and September (P>0.08).
Walleyes and hybrids may have inhabited exposed rock and steep rock habitats in June and July, when we could not sample these areas effectively. However, occasional electrofishing samples in these habitats in mid to late July and occasional seine hauls in exposed rock areas produced few stocked fish.
We did not capture enough yearling and older fish to analyze inshore habitat use, but electrofishing CPE suggested that both hybrids and Walleyes moved offshore during Summer. In July and August, CPE averaged about 0.3-0.05 times the CPE in Spring or Fall. There are many possiblee reasons for this movement (e.g., changing prey distribution), but, in Pleasant Hill Reservoir, offshore movement coresponded to the period when surface temperatures exceeded 22 degrees C. Field studies indicate that adult Walleyes prefer temperatures of 21-23 degrees C. (Hokanson 1977) and avoid temperatures of above 24 degrees C. (Fitz and Holbrook 1978). During midsummer in Pleasant Hill Reservoir, temperatures of 22-24 degrees C. (with at least 2mg/L dissolved oxygen) were available only at depths of 3-5 m, beyond the range that we could sample effectively by electrofishing.

Survival
Survival rates from stocking to October varied from 7 to 36% for hybrids and from 9 to 28% for Walleyes. Neither group had consistently better survival than the other; in 1981 and 1982, rates were similar between groups, but hybrids survived better in 1979 and Walleyes in 1980. Poor survival of hybdids in 1980 was probably due to their poor condition when stocked. Poor survival of Walleyes in 1979 may have been due to transport and stocking stress. We were not able to measure mortality at time of stocking, but many more Walleyes than hybrids were seen floating dead after release in 1979. In 1981 and 1982, stocking mortality appeared to be low for both groups of fish.
For each year class, ratios of age-0 hybrids to Walleyes in seine and electrofishing catches throughout Summer and Fall were similar to ratios in the Fall population estimates and in the harvest in subsequent years, except in the 1982 year class in the 1983 harvest. Persistence of these ratios in the harvest indicates that mortality rates were probably similar between the two groups after age 0. Differences in survival in 1979 and 1980 apparently developed by the end of June because ratios of hybrids to Walleyes in field samples remained constant after June.
Annual variations in survival of Walleyes and hybrids may also be related to differences in water discharge rates among years and loss of fish through the dam. Apparently, hybrids and Walleyes were lost through Pleasant Hill Dam at similar rates because survival rates were similar in 1981 and 1982, and ratios of hybrids to Walleyes for each year class were consistent over time. During our study, 1979 and 1982 were dry years and reservoir discharges were after stocking were low. In 1980 and 1981, heavy rains in late May and early June produced high discharges. However, in 1980, stocking was delayed until floodwaters had receded, thus newly stocked fish experienced relatively nlow discharges. If poor survival of Walleyes in 1979 and hybrids in 1980 was due to physiological stress, a negative correlation is indicated between survival and reservoir discharge rates after stocking for both Walleyes and hybrids.

Growth
Growth did not differ between age-0 hybrids and Walleyes, either within or among years (ANOVA;P>0.05). Fish in both groups completed annual growth by mid-October, when mean total length was 235mm and mean weight was 110g over all years. Mean lengths and weights did not differ between hybrids and Walleyes before age 2, when hybrids became consistently longer and heavier than Walleyes (P<0.05). By Fall 1982, the 1979 year class of hybrids averaged 555mm and 1,902g, and that of Walleyes averaged 519mm and 1,482g. We did not capture enough fish identifiable by sex to evaluate differences in growth between males and females.
The relation of length to weight was nearly identical for hybrids and Walleyes over all years. We developed length-weight regressions for both groups based on data combined for all years.

Foods
We examined stomachs from 1,305 hybrids and 789 Walleyes of all ages over all years. About 20% were empty. Invertebrates were eaten by both groups in all years but were an important part of the diet only for age1 and older fish in early Spring. Both hybrids and Walleyes were mainly piscivorous within 1 week after stocking. The most common fish eaten were Gizzard Shad. Hybrids had a slightly lower percentage occurrence of Gizzard Shad in their diets than did Walleyes in all years and also ate a wider variety of other fishes, most of which were littoral species. Predation by one stocked fish on another was noted only once, when an age-1 hybrid had an age-0 hybrid in its' stomach.
Lengths of forage fish in stomachs of stocked fish were similar among years; thus we pooled data for all prey species over all 4 years. For age-0 predators, we ran linear regressions of both mean and maximum lengths of forage fish eaten versus mean predator length, grouped by 25mm intervals. Mean and maximun total lengths of prey were directly related to predator total length. Regression slopes did not differ between hybrids and Walleye for either data set. For age-0 predators longer than 50mm, mean prey length was about 30% of predator length, which agrees with data from Cherokee Reservoir, Tennessee (Humphreys et al. 1987).
There was a discontinuity in the predator-prey length relations for age-0 and age-1 predators. Mean and maximum lengths of prey were lower for small age-1 predators (250-325mm) than for large age-0 predators, but for for predators longer than 325mm, values were similar to those of large age-0 fish. This discontinuity was due to the predominance of young-of-year Gizzard Shad in the diets of all age groups. In Fall age-0 hybrids and Walleyes averaged about 225mm and fed mainly on Gizzard Shad 50-90mm long. In Spring, at age 1, they fed on invertebrates before switching to young-of-year Gizzard Shad in early Summer. At that time, young-of-year Gizzard Shad averaged about 20-40mm. This produced a large decrease in mean and maximum prey lengths at predator lengths of 225-250mm, the length interval during which the transition occured from age-0 predators feeding on one year class of Gizzard Shad to age-1 predators feeding on the next year class of Gizzard Shad.

Harvest
Walleyes and hybrids in Pleasant Hill Reservoir showed similar seasonal and annual trends in vulnerability to angling. Angler success (harvest per 100 angler-hours) for all species was higher in 1980 and 1983 than in 1981 and 1982. Harvest rates for hybrids and Walleyes in the reservoir were about 1-3 fish/100 angler-hours in 1980 and 1983, but only 0.2-0.6 fish/a100angler-hours in 1981 and 1982. Most anglers did not distinguish between Walleyes and hybrids, but those who did found hybrids to be an acceptable alternative to Walleyes. From 1980 through 1982, 64-94% (mean,84%) of total harvest of both hybrids and Walleyes occured during April-June. Catch per unit effort for hybrids and Walleyes averaged 6.3 times higher during April-June than during July-September.
Harvest rates for both groups were higher for boat anglers than for shore anglers in all years except 1980. The discrepancy in 1980 may have resulted because nearly all Walleyes and hybrids harvested were yearlings, whiuch may spend more time inshore than do older fish. Most stocked fish were caught in the reservoir but, in 1980 and 1982, 6-33% of the total harvest for each group came from the tailwater. Harvest rates for hybrids were higher in the tailwater in 1980 but were similar in the tailwater and the reservoir in 1982. Most stocked fish taken in the tailwater were yearlings.


Discussion
The life history and behavior of a hybrid fish might be expected to be intermediate between those of the parent species. Nelson (1968) found that Walleye x Sauger hybrids showed morphological characteristics intermediate between those of the parents but more closely resembled the female parent. In our study, the biology of hybrids was similar to that of the Walleye (female) parent, but hybrids also exhibited some of the characteristics associated with Saugers
Our data on inshore habitat use by age-0 Walleyes agree with most published information. Age-0 Walleyes prefer sand or gravel substrates (Johnson 1969), although in early Summer they can be found over muck (Johnson 1969) and sometimes over all bottom types, including silt and rubble (Raney and Lachner 1942). The preference for finer substrates shown by age-0 hybrids agrees with the preference of Saugers for more turbid habitat (Schlick 1978) and suggests that hybrids may be more sessitive to light than Walleyes. The offshore movement by older hybrids and Walleyes during Summer agrees with data for both Walleyes (Rawson 1957; Johnson 1969) and Saugers (Cady 1945) from other waters.
The diet of Walleyes in Pleasant Hill Reservoir was similar to that reported in the literature. In general, Walleyes are pisciverous after reaching 50-60mm if forage fish are available (Maloney and Johnson 1957; Priegel 1970). When available, Gizzard Shad are typically the most common forage item (Walburg et al.1971; Fitz and Holbrook 1978). In Pleasant Hill Reservoir, Gizzard Shad were found primarily offshore and in the upper portion of the water column. Although hybrids also ate mostly Gizzard Shad
they ate more of other forage fishes than did Walleyes, including many species commonly associated with the bottom; this is typical for Sauger (Swenson 1977). In Cherokee Reservoir, Tennessee,hybrids fed mostly on Dorosoma spp. but also ate some littoral species (Humphreys et al. 1987). Lynch et al. (1982) found that hybrids fed readily on centrarchids and cyprinids in shallow ponds with dense macrophytes, habitats where Walleyes typically do not do well.
Growth of Walleyes in Pleasant Hill Reservoir was faster than average Walleye growth in Ohio reservoirs but slower than in Norris Reservoir, Tennessee. Hybrid growth was faster than most Walleye, Sauger, or other hybrid growth in Ohio. Growth of Hybrids in other recently stocked Ohio reservoirs has also been faster than average Walleye growth in the state. Hybrid growth in Pleasant Hill Reservoir was similar to that of hybrids in Norris Reservoir through age-2, but older hybrids had higher mean lengths than any Walleye, Sauger, or hybrid in Norris Reservoir. The fastest growth recorded for hybrids was for the initial year class in Cherokee Reservoir, Tennessee, where fish averaged 305mm at age-1 (Humphreys et al. 1987).
The difference in growth between age-2 and older Walleyes and hybrids in Pleasant Hill Reservoir may have been due to (1) hybrids use of energy for somatic growth rather than for gonadal developement, (2) heterosis in hybrids, or (3) Protracted feeding by hybrids. Failure to develop gonads was probably not a major factor. Under controlled conditions Walleye x Sauger hybrids have matured (Hearn 1986;T. Nagel, Ohio Division of Wildlife, personal communication). we sampled several ripe male hybrids (age 2) in 1981 and two gravid females (age 3) in 1982. Mature and immature hybrids of the same age were similar in length and weight. Thus, some portion of the hybrid population in Pleasant Hill Reservoir did develop mature gonads, and at the same time as Walleyes.
Heterosis in hybrids may have increased growth rates, but this possibility was outside the scope of our study. Work on the genetics of hybrids and Walleyes is needed to answer this question.
Protracted feeding by hybrids appears to be the most likely cause of their faster growth. After age-1, Walleyes lost weight over Winter, while hybrids gained weight. Walleye and Sauger differ in Winter feeding activity; Saugers feed more than Walleyes and contain more visceral fat (Dendy 1946; Schlick 1978). If hybrids, like Saugers, feed more than Walleyes over Winter, that could account for their faster growth.
Neither Walleyes nor hybrids exhibited consistently better survival in Pleasant Hill Reservoir. For hybrids stocked into small ponds, Lynch et al. (1982) estimated first-Summer survival rates of 31 and 83% in two of four ponds and no survival in the remainin ponds. They attributed poor survival to predation. Physiological stress and reservoir discharge appeared to be important in determining survival rates during our study. Reservoir discharge may be coorelated with many factors that could effect fish survival (e.g., turbidity, temperature, food supply), but we feel that direct loss of fish through the dam was the most likely cause for reduced survival after high discharges. Losses of Walleyes and Saugers through dams have been documented in various waters; heaviest losses occured among juveniles during high discharges from late Winter through Spring (Groen and Schroeder 1978;Smith and Andersen1984; Jernejcic 1986). Large losses of Walleyes have resulted in reduced population sizes and year class strengths in impoundments (Groen and Schroeder 1978). 
Harvest rates of Walleyes in Pleasant Hill Reservoir was low compared to other Ohio impoundments. Harvest rate in the tailwaters was also low but similar to Dillon Lake Tailwater, which is considered one of the best Walleye tailwater fisheries in the state. Walleyes typically have not produced good tailwater fisheries in Ohio even after years of stocking. Hybrids harvest rate was low in Pleasant Hill Reservoir but typical of other systems where hybrids have recently been stocked. However, in all these systems, harvest rates for hybrids in the tailwater were higher than in the reservoir and were similar to rates for Walleyes in some of Ohio's better Walleye reservoirs. Apparenty hybrids are more likely than Walleyes to remain in tailwaters or to move into tailwater areas from downstream. These fishery characteristics are further indications that hybrids exhibit some Sauger-like behavior. Sauger fisheries are typically better in tailwaters than in reservoirs (Nelson and Walburg 1977). Saugers are more migratory than Walleyes (Collette et al. 1977). In Southeastern reservoirs, Saugers congregate below dams in Fall and remain there through Spring, whereas Walleyes congregate there only during the Spring spawning run (Hackney and Holbrook 1978). Thus, an extended Winter fishery is possible for Sauger but not for Walleye. In Ohio, hybrids are commonly taken in tailwaters in Winter (R. Schaefer, personal communication).


Management Implications
Our data indicates that the biology of hybrids is intermediate between those of the parent species and that hybrids can be a reasonable alternative to Walleyes for stocking. The question remains, "What criteria should managers use in deciding whether to stock Walleyes or hybrids?" We feel that size and water retention time (reservoir volume divided by annual discharge) of impoundments may be useful in making that decision. Erickson and Stevenson (1972) related environmental features of Ohio impoundments to the success of Walleye stocking and concluded that large impoundments with clean gravel shoals and gradual water-level fluctuations were optimal; flood control reservoirs, which are characterized by large drawdowns, rapid water-level fluctuations, and variable discharges, had not maintained good Walleye populations because large numbers of Walleyes were apparently lost downstream. Willis and Stephen (1978) found that Walleye density and stocking success in Kansas reservoirs were directly related to retention time (low retention time indicates high discharge) and felt Walleye stocking was not justified in reservoirs with retention times less than one year. In Ohio, impoundments supporting the best Walleye harvests generally have high retention times-greater than about 0.7 year. There is a general relation between retention time and size of impoundment; thus, better Walleye reservoirs tend to be large, i.e., greater than about 1,000 hectares. High retention time does not guarantee good Walleye harvests, but no Ohio impoundment with a retention time of less than about 0.1 year has developed a good Walleye fishery(Ohio Division of Wildlife, personal communication), even after years of stocking. In contrast, excellent fisheries for hybrids now exist in tailwaters associated with impoundments of less than 500 hectares and retention times of less than 0.12 year. All of these impoundments (except Paint Creek Lake) had been previously stocked with Walleyes but never developed significant Walleye fisheries. These data indicate that, for large impoundments with retention times of about 1 year or more, stocking Walleyes is likely to be successful. For small impoundments with retention times of 0.1 year or less, stocking hybrids is more likely to produce a good fishery, particularly if anglers have access to tailwaters. More work is needed to determine the feasibility of stocking hybrids in impoundments with intermediate to high retention times.
A negative aspect of stocking hybrids is the possible dilution of gene pools in reproducing Walleye or Sauger populations. During this study we captured mature male and female hybrids. Male hybrids from Deer Creek Lake have been backcrossed with female Walleyes and the resulting eggs had about 10% hatching success (T. Nagel, personal communication). Hearn (1986) produced viable offspring from a cross of reciprocal hybrids and from backcrossing female reciprocal hybrids with male Saugers. Introgressive hybridization of Walleye and Sauger has been noted in natural populations (Billington et al. 1988). Where hybrids occur together with either parent species, they might interfere with reproduction of these fish or possibly spawn successfully with the parent species and introduce new genetic material into existing populations. More work is needed to determine the reproductive potential of hybrids in the field and the likelihood of backcrossings.
In conclusion, it appears that hybrids are a feasible alternative to Walleyes for stocking, particularly in impoundments with low retention times. However, before hybrids are stocked, consideration should be given to the possibility of genetic intermixing with existing populations of Walleyes or Saugers.
__________________


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## Mushijobah

Nice Read!

Here are some responses regarding the saugeye-sauger confusion I got from the fisheries curator and the asst. fisheries currator at OSU. I cut out some personal stuff in the e-mails and left all the fish stuff for your guys sake... 



Hello Dr. Cavender,


Can one tell the difference between a sauger and a saugeye purely by observational means? 

I have heard many different ways to do this including the pigment of the dorsal fin to a white blotch on the caudal fin. I have also read into a few publications that elude to the fact that a saugeye may carry similar physical qualities to a walleye or more commonly a sauger.

I appreciate your help. This will help identification go much smoother on the shock boat & the riverbank!

Kyle 




Kyle,

Concerning the saugeye/sauger question it would be good to know where 
you are catching these fish. Stream saugers are rare and I would 
have to go way back to find the last sauger I found in Lake Erie. If 
you are fishing on of Ohio's larger streams especially below a dam 
where you know saugeyes have been stocked then chances are you're 
getting saugeyes. They can be common including Buckeye Lake. If you 
are in the Ohio River where saugers are common then there is a 
problem with the small juveniles. In larger fish like 400mm TL then 
the dorsal fin pigment will work. I always look for discrete black 
spots especially along the lower part of the fin, and no black 
pigment fusion in the fin membrane. I am trying to develop an 
additional character but this would involve looking at the teeth. We 
bring back small individuals from the Ohio River for lab 
identification but these are tough.

Ted


My response,


Ted,

I am catching these fish primarily in the Scioto (downstream of Greenlawn, which as I'm sure you know, is the last dam on the Scioto) and in Alum/Big Walnut creek from their intersections with Morse all the way down to the 3 creeks region. The ones I capture closer to Morse are definite saugeye. The fish I catch in the Bexley to 3 creeks vicinity of Alum and the 3 creeks vicinity of Big Nut are very difficult to tell apart. The fish I do catch are in the 12-17" range and show dark speckling/ovals on the dorsal membrane.... Much different from the obvious saugeye I catch in the actual reservoir spillways. Although I realize they are not the typical sauger habitats, their range extends into those regions I catch them in and there are no dams downstream preventing the migration. Let me know what you think, I really appreciate your help!

Kyle


He forwarded the email to the asst. curator of fisheries at OSU,


Hi Kyle,

I saw your e-mail to Ted this afternoon. A few years ago (1997) 
current DOW District 5 Fisheries Biologist Kipp Brown and i were 
working on a project with Ted on fishes of Alum Creek and we caught a 
sauger just upstream of the confluence with "Big Nut", by the 
way. OEPA has captured several individuals in Big Nut as well. So i 
wouldn't be surprised that you are catching sauger where you're fishing.

If you're catching more slender fish with distinct black spots on the 
dorsal, with no sign of convergence of the spots into "bars" and no 
black spot at the posterior insertion of the spinous dorsal, then you 
can be fairly confident you've got a sauger. If you'd like you can 
bring in a specimen for us to look at sometime. I'm here most days 
0800 to 1700 while Ted is often in after 1500 weekday afternoons.

Marc



I hope this information helps!


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## fishmeister

I guess I'll weigh in on this- I do fish genetics research. The first dorsal fin is the key for identification. The small spots between spines are pretty good indicators, but may be highly variable. The large black splotch at the posterior base of the fin is also a very good indicator, but can be confused with fused spots between spines. The black splotch is inherited from walleye, so saugeye will have this and sauger will not. So, in short, look at the spots to tell what you have. But beware because this works well only for F1 (first generation) crosses. Some additional backcrossing has been detected, and the traits can get rather muddled. For example, see White et al. (Transactions American Fish. Soc., 2005)- ten of the fish that were identified in the field as sauger were later identified as saugeye, but for the most part, field id worked ok. Short of doing the genetics, go with the dorsal fin.


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## Mushijobah

fishmeister said:


> I guess I'll weigh in on this- I do fish genetics research. The first dorsal fin is the key for identification. The small spots between spines are pretty good indicators, but may be highly variable. The large black splotch at the posterior base of the fin is also a very good indicator, but can be confused with fused spots between spines. The black splotch is inherited from walleye, so saugeye will have this and sauger will not. So, in short, look at the spots to tell what you have. But beware because this works well only for F1 (first generation) crosses. Some additional backcrossing has been detected, and the traits can get rather muddled. For example, see White et al. (Transactions American Fish. Soc., 2005)- ten of the fish that were identified in the field as sauger were later identified as saugeye, but for the most part, field id worked ok. Short of doing the genetics, go with the dorsal fin.


Didn't think it was as easy as people said!


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## fishmeister

Yeah, saugeye is a confusing fish because it is fairly variable morphologically. Its pretty funny that few (if any) people on this site get as worked up about hybridization among the sunfishes! Now there's a tricky subject.


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## Mushijobah

LOL yeah, I know a hybrid when I see one, but what two went into it....i have no idea!


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