Will LMG and BG cross/inter-breed?

My BIL says I have some crosses in my pond. They the mouth of a LMB but the body/colors of a BG.

It's been done artificially but the offspring rarely survive. Very, very unlikely in a natural setting. Someone is pulling your leg or isn't very knowledgable.

Most likely the large mouth on these fish can be attributed to a sunfish with a larger mouth crossing with your bluegills i.e. green sunfish. Hybrid sunfish can be very common if the conditions are right and species are present.

What's a BIL? Oh brother-in-law?

Like CB1 sez, no.

IIRC BG & LMB, when force crossed in the lab or hatchery, exhibit some success as far as eggs being fertilized, but very little success at producing viable hatchlings and virtually none grow to adulthood. I have a copy of the paper showing this at home, and ewest may be able to post the link.

IMO (like Cecil's) what you have is a SunfishXSunfish hybrid, quite possibly the classic BluegillxGreen Sunfish. GSF are frequently described as having a "bass mouth" as are the hybrids. It could just be GSF.

See HBG Pic/Question for pics of hybrids and GSF.

sounds like a warmouth(stump-knocker as we know them) to me....big mouth like a bass but a small body like a bream..where are you located at?

There is a pic but I can't get it to copy and post

Micropterus salmoides X Lepomis macrochirus 66 %


When Micropterus and Lepomis were
crossed two offspring were produced. When
Micropterus eggs were used 81.67% were fertilized,
30.3% hatched,a nd 0.2% (2) survived.
The two offspring that survived were different in appearance (Figures 3 and 4) and behavior.
The smaller fish had several noticeable
abnormalities. h was apparently blind
in one e)e and was much darker in appearance
than the larger one. Some times the small hybrid
would swim the circmnference of the
plastic pool at the surface with its dorsal fin
out of the water. At other times it would assume
a vertical position in the water rather
than a horizontal one. These abnormalities
of vision, pigmentation, and equilibrium
would appear to indicate neural deformity.
When Lepomis females were crossed with
Micropterus males, 85.0% of the eggs were
fertilized and $.0% hatched. Those fry that
hatchedd ied shortlya fter•,ards.N oner eached
a free-swimmings tage. In this crossa nd in
its reciprocal fertilization rate was high;
however, it was quite difficult to obtain viable
offspring.