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There have been many comments about hybrid bluegills (bluegill X green sunfish) but not a good discussion. These hybrids are normally 80% or more male and are fertile. They are very brightly colored with bright yellow fins.
Many people have said that their young revert to green sunfish. Is that true? In a pond with only hybrid bluegills, I would think that ¼ of the young would be bluegills, ½ would be hybrids and ¼ would be green sunfish. If left alone, I would think that a continuum would form from pure bluegills to pure green sunfish. What are the facts?
If LMB were added to this pond, would they eat the babies that are shaped more like the green sunfish first? If this happens, does this mean that the hybrids would slowly revert to pure bluegills?
Do the hybrids really exhibit hybrid vigor? That is, do they really grow bigger, faster and are more aggressive than pure bluegills? After many generations, do hybrids still exhibit hybrid vigor? Could someone explain this subject?
If in fact hybrids do grow bigger and faster, do these males dominate the spawning grounds of bluegills? If we have both bluegills and hybrids in our lake, what will we end up with?
Hybrids of bluegills, green sunfish, redear sunfish, pumpkinseeds and other members of the sunfish occur in the wild. Would any of these hybrids have any use in our lakes?
Other than the fact that hybrids don’t have many females, are there any other disadvantages to using hybrids in our lake? Are there any other definitive comments about hybrids?
Norm Kopecky
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Norm, the guy that stock my pond talked me into them. they are by far the prettiest fish in the pond. my draw back is they just don't produce enough young. i have very few small gills in the pond. i just stocked 100 6" bluegill to get the population up , probably should went with more. they fight great though. i catch them on small spinners , so that tells me their probably eating my fatheads and shinners too. there mouth is 3 times a bluegill.
i only wanted to have some fun
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Norm: Your "1/4 Bluegill, 1/2 Hybrid, 1/4 Green Sunfish" view of the first generation offspring is a simplification that I believe would be correct if sunfish had only one pair of chromosomes. All the higher animals have multiple pairs, so the offspring would indeed run the gamut from "pure bluegills to pure green sunfish."
At first it seems to me pretty unlikely that the offspring would veer very far from a 50-50 mix of BG-GS, but given the huge numbers of young involved from even a few breeding pairs, they probably would include nearly pure BG, neary pure GS, and a number of intermixes in between these extremes. The fry that were viable and well adapted to live in the pond in question would grow and could end up dominating.
I can see how this could lead to offspring that would eventually seem a great deal like either green sunfish or bluegills, given variation in different ponds' environments and management strategies. I've read from some posts here that green sunfish can be managed into comparative oblivion, and from others on how you can't get rid of them without renovation. So conditions could be correct for the later offspring to thrive as near-GS or as near-BG.
As for "hybrid vigor," all organisms carry "bad genes" which, alone or reinforced, cause traits which may be fatal, a challenge to overcome, or no problem. I carry genes for lopsided ears, nearsightedness, and an enzyme deficiency called Gaucher's Disease. If reinforced, the results are respectively no problem, poor distance vision, and usually fatal. Since my wife is not closely related to me, our kids are attractive (IMHO), alive, and see well. It's hard to get more unrelated than a different species. I think "hybrid vigor" results from near crosses which are viable, where the parents have completely different sets of "bad genes" so very few or none are reinforced. This gives first generation hybrids which truly have the best of both worlds.
"Live like you'll die tomorrow, but manage your grass like you'll live forever." -S. M. Stirling
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The two topics you will never change anybodys mind about is abortion and hybrid bream. I stocked my pond with hybrid bream three years ago, got them from the infamous Ken Holyoak. He sells what he calls Georgia Giants. He says this is not the standard cross, all the pros disagree. The hybrids are at a pound and do IMO have hybrid vigor. They are very aggressive and fast growing. Some(Cecil?) consider hybrids an ugly fish, I disagree. That said I am concerned about what they will revert to, even Ken says you need to drain your pond every five years and start over. I have no plans to drain my pond. Starting year two I have been adding Coppernose bream each spring. In doing so I am hopeing to increase my forage and convert over to Coppernoses. Whatever something is working. My pond is three years old and I am catching four pound cats, two pound hybrid stripers, one pound bream and as of last Saturday(pat on my back) a three and a half pound largemouth. As much as I currently love my hybrid bream if I was starting over I would stock coppernose and redears. www.kens-fishfarm.com
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It depends on your goals. For a person interested in raising catfish and huge bgill, by all means go with the hybrids if you're feeding. If you're like most and want bass, steer clear...you don't want their predatory instints or their breeding characteristics.
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Are there any problems with having both bluegills and hybrid bluegills in the same lake?
Norm Kopecky
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Norm, on this board, you'll run into resistance stocking both, here's my experience. Some older ponds already have established fish populations where draining isn't an option, you simply manage what's there. Many Texas ponds have an abundance of bgill, often it's time to fry up the big ones, and toss the little guys out. I can say that the hybrid bluegill do get larger than the natives when fed. They also agressively hit spinner baits as well. They cross breed with the native bgill and throw offspring with brilliant colors, it wouldn't suprise me if a green sunfish is produced somewhere along the way, I have caught pure green sunfish in these ponds as well. But, in the cross bred bgill populations, while the green sunfish is a predator, it's also preferred eating over the native bgill by both bass and catfish, they make excellent bait. In a 2 acre pond, I do not have a problem with hybrids or green sunfish. I have friends who "live" for catching/eating large bgill, the negative impact of having hybrid bgill is minimal and easily managed in a small pond that is managed. While I don't have 10 lb bass, I do have 6lb bass, 4 lb cats, crappie that don't reproduce, and huge bgill and redear. I'm in the process of "trying" to duplicate this environment in a 5 acre pond + adding wipers. I'm spending the 1st year getting a heavy native bgill population in place first. Note : My management tactics aren't viewed as "by the book", I believe in selectively stocking mature "tape measure" adults with superior genitics to produce offspring for bass, bgill (both kinds), and redear's. I only buy catfish and crappie to replenish what I take out and eat.
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Eastland,
I'm curious...how is it you have "crappie that don't reproduce"?
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Eastland , where you hook up with the crappie and your positive they don't reproduce? black or white? thank you
i only wanted to have some fun
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They are black crappie and have been purchased from several sources...Dunns & Overtons. We only stock 100 per season, we have never seen/caught anything smaller than what we stock. Water visibility ranges but is generally about 16-24". We have a very fertile pond in Fayette County (about an hour east of Austin) Generous watershed area and around 37" annual rainfall. Zillions of bgill, not uncommon to catch a lot of bass too. My guess is that the crappie do reproduce, but the fry don't stand a chance. This is only my observation, but there is a LOT of gravel along the shoreline, roughly 2/3rds. Bgill nests are dotted along the bank year round with abundant reproduction. I believe the rock structure and the water visibility are the keys to eliminating crappie reproduction.
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Thanks for all of the comments. We actually stocked more green sunfish in the beginning (2000) than bluegill and hybrids. So far this year, we've only caught one green sunfish even though they are much easier to catch than anything else.
Theo, from your comments, I see that I really don't understand hybrid vigor. Hybrids of various sunfish species are common in the wild. If these fish are more fit because of the supression of deleterious genes, why don't these hybrids quickly dominate the population and drive the parent species to extinction?
Dave Willis, Bill Cody, Greg Grimes (*****, my vote) and other professionals, I would love to hear your comments on this subject.
Norm Kopecky
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While the various sunfish hybrids CAN reproduce, they probably all have lower effective fertility than the parent species (lower reproduction and/or retention). Lots of near-species crosses are completely sterile, mules being the classic example.
Alternatively, it's like my 13 year old says - if hybrids were all that great, we'd eat all our meals with sporks, fnives, and knifoons, not just school lunches.
"Live like you'll die tomorrow, but manage your grass like you'll live forever." -S. M. Stirling
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Hi Norm.
I didn't answer earlier, primarily because I haven't worked too much with hybrid sunfish. We did "make" some bluegill-green sunfish hybrids quite a few years back by stocking male bluegill and female green sunfish into an otherwise empty pond. I recall that we had to cut the big black "tab" off the gill flap of the male bluegills for the female green sunfish to accept them for spawning. I've had other people tell me this is NOT necessary, but my old prof (Steve Flickinger) taught me this, and he was good at this business.
As you already know, all of these sunfishes can interbreed. Most sunfish species use visual cues to recognize the right species (that’s what keeps them separate species). So, when there is overabundant aquatic vegetation, the visual cues are more likely to be obscured, the females may accept a male of a different species, and we get more natural hybrids. Also, we get more natural hybrids when one species is VERY low in abundance compared to the other.
This natural hybridization is, I think, what causes some of the consternation over the highly male offspring that supposedly come from this cross. If you have a pure male bluegill and a pure green sunfish, then the offspring of that cross are supposed to be something like 97% males. However, if one of the parents has a little hybridization in their background, then the percent males in the offspring will be lower. So, people making the original crosses need to be very careful about their sources of parents.
Now, let me change topics to what I THINK that I know about hybrid vigor. Apparently, the hybrid vigor is a "true" occurrence, and creates a fish that is aggressive and fast growing, but this only applies to that first generation (the F1 hybrids in the term used by geneticists; in this case, the offspring of that initial cross between the male bluegill and female green sunfish). In subsequent generations, or in backcrosses with either of the parent species, the vigor does not occur. I don’t have much experience with this, but folks who do know (including Steve Flickinger) are pretty adamant that growth will be slower with these inter-mixed future generations of hybrids.
Hope this helps.
I just got back from some field work at Angostura Reservoir on the south edge of the Black Hills. Have you been down there? My, what a wonderful resource!!
Finally, can we give Greg 6 stars, and balance out his overall rating to a 5?? :-)
Dave
Subscribe to Pond Boss MagazineFrom Bob Lusk: Dr. Dave Willis passed away January 13, 2014. He continues to be a key part of our Pond Boss family...and always will be.
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Norm - I cannot add any more specifics to your hybrid topic than Dr. Dave has provided.
Here is one experience about one of your questions. Ref: LMB eating babies shaped like gsunfish first & do hybrids slowly revert to bgill. I have had some expeience with this in a small 1/4ac pond with natural production of hybrids (bluegill - gsunfish cross). Initially there was a spawn that produced numerous hybrid bgills. I will call this spawn F1. This F1 group grew pretty fast compared to the same age (year class) bgills (guessing 15%-30% faster). When F1's were about 2 yrs old the LMB population was supplimented with 10-13 fish 8"-10". Harvest of some hybrids for table use began when they were 8"-8.5".
All green sunfish whenever caught were removed. After ten yrs now, most panfish caught appear to be bgill. Rarely are greenies caught and 5%-10% of the panfish caught are what look like to have some hybrid markings.
Keep in mind: pond is small rectangle shaped 1/4 ac., one end slopes to shallow, sides steep 3:1, 8 ft deep, low weed growth due to white amur, 8 -12 channel cats also present now 18"-24", bass never harvested (unless bleeding). Predators seemed to have heavily cropped the greenies thus lowering production of future F1's. Selective harvest of hybrids lowered frequency of backcrossing. All Young panfish get pretty heavy predation. Bgill "SEEM" to have a tendency to often breed true ie bgill to bgill. Reproductive isolation due to behavior probably plays a big role here. Panfishes in this pond with some human management or intervention seem to be reverting to a bluegill dominated pond.
Note: I think the hybrid fish capable of reproduction only belong in private waters with no overflow to streams or in waters not connected to streams or rivers. Hybrids capable of reproducing when mixed in with our natural fish populations of public water will cause the fishery resource and gene pool to deteriorate and compromise the quality of our natural fishes. Thus when "science" needs purebreed fish for some reason they become difficult if not impossible to locate.
Nature has numerous built in features that prevent hybrids in nature. BUT, nature is not perfect. Natural production of fish hybrids in nature usually results when two different species happen to be spawning in close proximity and sperm from one species drifts into the area of another species' spawning site. Very rarely do two different species in the wild intentially interbreed. Often if they do the genetics of egg and sperm are not compatable and embryo does not form or it soon dies or is deformed and survival is very short in the wild. Survival of the fittest.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
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by PAfarmPondPGH69, October 22
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