I was fishing a bit today and caught an 8 inch largemouth. The only bass I stocked were 3" LMB approximately 2 months ago. I have, however discovered that there are some mystery fish in the 3 year old pond. In June, I had a 16" LMB actually jump into my rowboat (I wasn't fishing...just rowing)!!! The only thing I had previously stocked (about a year prior) were YP and fatheads. This is a rain-filled earth pond with no inlet or outlet. 2 hours later, I caught a 12" bullhead. I removed the bullhead from the pond, but with the bass, I was so surprised that I had it (and that it jumped in the boat) that I quickly threw it in the water without thinking about how it might chow on future stockings...and I stocked several hundred small fish a couple weeks later. I am sure he is thankful and eating very expensive dinners.

Long story aside, my question is:
Should my 3" bass now be pushing 8" after 2 months if there was plenty to eat (fatheads, gambusia, tadpoles, bugs, etc)?

Or is this another mystery bass that is going to eat my fingerlings panfish?

3" to 8" in 2 months is possible with great forage available but pushing it, especially for Michigan. It is perplexing how a 16" LMB and a 12" got into your pond if it has no inlet out outlet of water connecting up to it... Perhaps you have a neighbor who thinks they are being helpful? This is all speculation, as we'll never know for sure... It may very well be your 8" bass is just a fast grower of your 3" bass or it may be offspring of your 16" bass and other unknown bass that spawned previous year without your knowledge. How large is your pond? Do you have a reasonable sized area that is flat without obstruction? If so, you may be able to do a good seine survey and get a better idea as to just what you have going on in your pond...

1.5 acres. I do have a large 6ft deep (currently 5ft deep) swimming area that might be good for seining at some point, but I doubt I'll mess with it this season.

My best guess on the 16" bass is that maybe it snuck in with the first batch of fatheads that I put in 2+ years ago. The place I got them was a trout farm (bring your kids to fish) and only sold fatheads on the side. At the time I puchased them, they no longer sold LMB for stocking, but they used to. I did notice one small rainbow trout in that first batch, and it promptly died in the warm water. A small LMB (or a few) would have a much easier time hiding among large numbers of FH minnows, and I probably wouldn't have noticed them. They no longer sell FH there. Yellow bullhead, who knows. There's the old "eggs on birds' feet" scenario, but I always thought the chances would have to be slim on such a small scale and short time period. Construction on the pond was completed a little less than 3 years ago, and this is the first year it's actually full. I don't have any neighbors with ponds and only one that is even close to me...I doubt he'd do anything like that anyway.

My original plan was to go with SMB/YP/RES, so I was certainly a bit disapointed to see a big lmb in there. Luckily (I guess) SMB were too hard to get, RES seem to have some trouble surviving, and my goals have a changed a bit, so I changed plans to go with LMB/BG/YP and I may have some RES and pumpkinseeds as extras to eat snails.

Bullheads often ride in with FHM as well. Even if the place doesn't sell or raise them, they still find a way to mix in with the FHM.

LMB/BG/YP is a good combination with a pond your size. Mix in a few PS or RES and you'll have a great little fishing pond. Are you shooting for a balance or more of trophies for bass or panfish?

Big, trophy fish would be really nice, but at this point, I think the most important thing is that when I find time to fish, I want to actually catch some fish. If I can go out for a few hours and catch dinner periodically throughout the summer, I'll be very happy.

Plus, my kids are young (4 yr old and 4 month old), so being able to easily catch stuff will be important for quite some time.

I may be building a small 1/5 acre pond this year or next. Depending on what I do with that project, it may place some role in the big scheme as well.

A smaller pond idea is great. Just load it up with tons of hungry fish. Youngsters don't need to catch fish to be happy, just lots of fish... Often times you can place all the cull fish from your bigger pond into it that you don't want to eat.

Break it down for me, what did you stock, how big were they, how many and when?

Yes, I use fatheads for catfishing and quite often you find little bullheads in them. As for the bass I don't know.