Pond Boss Forums STOCKING A NEW POND Types of fish to choose Hybrid bluegills

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