Hybridization Among the Big 3 catfishes; Why Doesn't it Occur Naturally??

Discussion in 'All Catfishing' started by Catcaller, Dec 23, 2007.

Should channel/blue cat hybrids be made a stocking option in our public lakes/rivers?

  1. Yes...why not?

  2. No...absolutely not.

  3. Only in private lakes

Multiple votes are allowed.
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  1. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    Scientists have successfully crossed the blue cat male with the female channel cat in a laboratory setting.

    The result??

    A cat that is less suseptible to parasites and diseases than blues are...yet grow faster, and more efficiently digests and utilizes the food that it eats than does a channel cat.

    It also is more aggressive than a channel...and is easier to catch than either parent species.

    A more cost effective breeding procedure is the only thing preventing it from becoming the go-to catfish of choice in farms and hatcheries. But it is however more than possible.

    Hybridization in the wild is a whole other ball game.

    What prevents the swapping of genes between similar species in the wild from occuring??

    The fact of the matter is that it does quite commonly occur between similar species.

    Changes to the fish's environment or new fish's introduction where they don't naturally occur is one reason.

    Channelization and manmade dams for example present an un-natural concentration point and impedes the natural/traditional spring spawning migrations of several species...pushing sexually mature fish of similar species to spawn together....either by accident, or by design.

    And then obviously engineered genetic changes in the fish themselves are another form of hybridization. Case in point...the whitebass/striper hybrid...also known as the wiper...and also the afore mentioned channel/blue cat hybrid.

    Over 200 different naturally occuring hybrids have been documentated among North American fishes though.

    For example...it is well known that sunfish commonly cross with various minnow species. As well as the occasional natural reproduction of the saugeye where walleye and sauger overlap.

    But yet other species cannot be crossed even in the most rigourously controlled experiments.

    Blue and channel cats fall somewhere inbetween. Hybrid blue and channel cats dont occur naturally...but they can be crossed in an un-natural setting. By simply stocking like numbers of opposite sexes of channel and blues in a tank together...the abscence of a suitable mate of the same species will be overlooked...as catfish become open minded when the spawning urge peaks.

    This is not the case in the wild....scientists explain that when two similar species occur in the same territory...barriers to hybridization in the wild can be either in the location or the timing of the spawn, differing spawning technique and courtship rituals, or a bio-chemical conflict between the egg and the sperm may also occur. usually a combination of these natural barriers prevent crossing in natural habitats.

    Home ranges and habitats for the catfish do overlap, and blues and channels all spawn in about the same way.

    Spawning for North American catfish all begins at about roughly 70 degree water temps...occurs in nesting cavaties...and often in muddy water...which makes visual identification a non-occurence.

    But yet somehow...blues, flats, and channel are determined to avoid each other in the wild when they spawn...and will go to great lengths to do so.

    Since blues and channel hybrids can in fact be produced under artificial conditions...some factor besides timing and location must account for their genetic purity.

    Many scientists reason that since fish have an acute sense of smell...they must use it to detect pheromones in social interactions such as spawning.

    They go further to theorize that catfish can distinguish one individual fish from another by the odor of their slime coat.

    If this is in fact the case...it would be easy to make the assumption that they can then sense and reject a fish of another species that has entered their spawning area.

    The instinct to reject other species appears to be strong in catfish...unless they just are given no other choice.
     
  2. brinley45cal

    brinley45cal Active Member

    Messages:
    2,606
    State:
    kentucky
    If the cats did it own there own ok,but i dont like the idea of people playing GOD .Trying to make them quote better.If GOD wanted them that way he would have made them that way.I say if its not broke dont fix it.there little experiment might go the wrong way and have results on our cats we dont want.JMO
     

  3. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    This is hardly a "new" concept.

    Genetic engineering has been done with several other species...the wiper...the florida strain largemouth bass...the tiger musky...the jumbo bluegill...the saugeye...ect.

    From my understanding...this channel/blue cat cross was manufactured in the face of an attempted Asian takeover of the farmed catfish market.

    Considering the success of a few other species hybridization...it may not be a totally bad thing.

    But therin lies the rub...we would have no way to know for sure the impact until after the fact. When it's too late.

    Case in point...just ask those who introduced the flathead into places where it is now eating up indigenous species of fish...some of which are on the endangered species list.

    Or the case of the european zander...a jumbo cousin of the walleye. It was introduced into one water shed up north...and the public outcry by walleye fishermen produced the effect of the project being abandoned.

    Luckily...apparently...it didnt blow up in their face...but the jury is still out on that one.
     
  4. curdog

    curdog New Member

    Messages:
    896
    State:
    Sheridan, Arkansas
    I voted no because from what I read none of the scientist put them in a area where thay could be monitered to see if thay would clean an area out of the other type of fish.
    There are people are up in arms against the Flathead catfish because thay are devastating the fish in that area. And these hybred catfish is supose to be more aggresive.
    The scientists are going to keep on messing with nature till thay open a pandora's box that thay can't put the lid back on.
     
  5. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    Actually this has been going on far longer (Since 1966) than the article I initially read indicated (I didnt notice it indicating)...but on further research...I found another news report from 2006 that detailed the operation of a seperate group that is selling these same engineered fish to fish tanks across the US by the millions of fingerlings.

    The other source also detailed an alternate...and disturbing...actually VERY disturbing...to me at least...breeding program. (Read it below and you'll see what I mean)

    I wonder how many blue cat males they have killed with a "thwack" (As they describe it)...to engineer these hybrid fish?

    And more importantly...where did they get them?


    http://www.nwanews.com/adg/national/167708/
     
  6. Ketch

    Ketch New Member

    Messages:
    469
    State:
    Minnesota
    Are these hybrids sterile? How well will they reproduce naturally? What are the differences in habitat from the parent species? Does this aggressiveness cause cannibalism (some failed hybrids this has been the case)?

    Because of the the aggresiveness, does the make them an "invasive" or "nuisance" fish as the flathead is sometimes considered?

    Now if we only allow these in private lakes, you know good and wel that sooner or later a flood will occur, and they will get transported into the river. That or someone who thinks they know better than anyone else will manually transplant these fish.

    I think until much more can be learned, they should be considered an illegal fish and not acceptable for sale.
     
  7. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    If you think it may not be acceptable now...wait until you read that link I just posted a few minutes ago!
     
  8. Ketch

    Ketch New Member

    Messages:
    469
    State:
    Minnesota
    I've read similar stuff before. I just read the link, kinda sounds like a big head carp waiting to happen.
     
  9. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    I gotta agree there. The introduction of bighead carp (Aka: Asian Carp) was a well intentioned endeavor to help improve water quality at sewage treatment plants...until they inevitably escaped into the Mississippi river basin.

    The rest is history...which continues to unfold before our very eyes.

    Have you seen the tournaments where they manuever their boats on plane...and then use nets to catch the carp as they jump out of the water?

    I read an article about that here awhile back...and some were weighing in hundreds of pounds of these carp during these tournaments.

    I guess the problem has gotten that bad.
     
  10. Ketch

    Ketch New Member

    Messages:
    469
    State:
    Minnesota
    Yeah, just another way that someone knew better without doing enough research first. That's why I am so opposed to it.
     
  11. Pfunk

    Pfunk New Member

    Messages:
    141
    State:
    Lake Fork - Texas
    Yea unless there is a huge advantage to all of this, I'll say leave em be.. But it does appears as if there may be at least some advatage, maybe a little too soon to go introducing them to our ecosystem though....

    Very interesting article... I assume they know what they are doing..

    I can't help but wonder how they taste ;)
     
  12. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    I don't know the answer to that one.

    What I do know (Or at least thats what we're told) is that the hybrid wiper cannot spawn...even though they do in fact run up the Neosho river every spring...and they do in fact carry eggs.

    Does anybody know if there are other hybrids that actually do spawn?
     
  13. Ketch

    Ketch New Member

    Messages:
    469
    State:
    Minnesota
    Saugeyes have been shown to reproduce with very low reproduction rates. Also, the only recorded reproductions have occurred between walleye and saugeye or saugeye and sauger. For some reason they can't identify a successful reproduction of saugeye and saugeye.
     
  14. curdog

    curdog New Member

    Messages:
    896
    State:
    Sheridan, Arkansas
    If this has been going on since 1966 here in Arkansas thay are probably already in the waterways. Now that you mention it people around here called what I called a channel cat a blue channel cat. I just figured it was a local thing. So it must be a Hybred. I never made the connection till this thread. Learn something new every day.
     
  15. Pfunk

    Pfunk New Member

    Messages:
    141
    State:
    Lake Fork - Texas
    Hope this isnt dup info. But i thought this might be helpfull...



    In the production of straight channel catfish, the most commonly grown catfish, fish are allowed to spawn naturally in ponds. Fertilized eggs are removed from ponds and incubated in indoor tanks; fish fry are raised indoors until they are large enough to release back into ponds as fingerlings. In the artificial technique, female channel catfish are injected with a natural hormone to induce them to produce eggs. The eggs are removed from each fish and mixed with blue catfish sperm; fertilized eggs are incubated in indoor tanks.
    "Typically, only half the brood channel catfish may spawn naturally in ponds," Phelps said. "Using the artificial technique, about 90 percent of the females ovulate, resulting in a significant increase in the number of fry produced per acre of brood fish."
    From the time they hatch to the time they are harvested, overall survival is about 30 percent better in the hybrid fish, Dunham said.
    In his study of the economics of hybrid production, Phelps evaluated the process from spawning to harvest. He found that hybrid fingerlings can be produced at the same price as channel catfish fingerlings. Fingerlings are generally produced at a specialized breeding facility and sold to fish farmers. Phelps found that fingerling producers can ask a higher price for the hybrid fish, and farmers can still increase their profits.

    Source http://www.ag.auburn.edu/aaes/webpress/1995/catfish.htm
     
  16. catfishjohn

    catfishjohn New Member

    Messages:
    10,217
    State:
    Greenup Co. KY
    I think if they do it on their own,why not. Probably doesn't happen often at all and it seems to work fine.
    I don't see much reason in us messing with nature to possibly have a disaster on our fisheries and waterways. Just my .02:wink:
     
  17. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    Here is an article I found about hybrid fish relating briefly about their spawning habits.

    It states that a small percentage of hybrid fish are in fact able to reproduce.

    Guess it depends upon who you ask...a Kansas fisheries biologist once told me that wiper are incapable of reproduction. I have also read the same response in an article in an outdoor magazine a few years back.

    http://www.fish.state.pa.us/images/pages/qa/fish/hybrid_breeding.htm
     
  18. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    Well Santa...bring us a few big air tankers full of Mark Twain 'esque blue cats and flathead...arrange a drop in the big muddy...and we'll deal with this problem!! :wink:
     
  19. kat in the hat

    kat in the hat New Member

    Messages:
    4,875
    State:
    Missouri
    My GUESS as to why hybridization in the wild is rare...Nuances in their breeding habits. Their habits are very similar in many instances, but not identical. For one, channel cats become sexually mature at a smaller physical size. They are able to utilize smaller crevices than blues, or flats for their nests, often spawning under the edge of a rock, or in cavities too small for even the smallest of breeding size flats. I think that generally, and I'm not an expert or biologist, but flats and channels spawn mostly in sandy/muddy areas, in rootwads, hollow logs, or holes in the bank. I think that blues prefer more rocky areas to spawn. I think that even minute differences in their habits would make cross-breeding in the wild very rare. They could also have very different "courtship" rituals that could be unknown to science, or behavior not conducive to cross breeding. Flats often feed on blues and channels, so wouldn't it be natural that they have fear of them, and avoid them whenever possible?

    I know a guy that had a large irrigation lake that he caught a 67# catfish from. He thought he had caught a world record channelcat, so he contacted MDC. The agent couldn't possitivly identify the fish, so he took tissue samples, and it turned out to be a blue/channel hybrid. His family built the lake, and only channels were supposed to be stocked. Either the fish was mixed with the fingerlings 30 years ago, or it was caught somewhere else, and put in the lake. I know they hybridized blues and channels for commercial food production in the south, but don't know when, and it's not a common thing in Mo. It's still a mystery whether this happened naturally, or commercially because MDC did the stocking, and they don't raise hybrids.

    [based solely on opimion]
     
  20. Catcaller

    Catcaller New Member

    Messages:
    1,511
    State:
    SoutheastKansas
    According to the article...the hybrid blue/channel tastes like channel cat.

    As a matter of fact...these fish are probably already stocked in the seafood section of a grocery store near you.