With Dave Willis help we have been chasing this rabbit for 3 years now all the way to checking with the top genetics guys around. Here are some examples.


Evaluation of Male Bluegill X Female Green Sunfish Hybrids for

Stocking Mississippi Farm Ponds 1

MARTIN W. BRUNSON

Rice Research Station, Louisiana Agricultural Experiment Station

Louisiana State University Agricultural Center

Post Office Box 1429, Crowley, Louisiana 70527, USA

H. RANDALL ROBINETTE

Department of Wildlife and Fisheries

Mississippi Agricultural and Forestry Experiment Station

Mississippi State University

Mississippi State, Mississippi 39762, USA





Largemouth bass effectiveness

in controlling F2 hybrid recruitment was evidenced

by the following: in the three drained ponds

containing largemouth bass (two bass/feed, one

bass/no-feed), the mean number of F2 hybrids per

hectare was 35; in the three drained ponds without

largemouth bass (two no-bass/feed, one no-bass/

no-feed), the mean number ofF2 hybrids per hectare

was 2,142. Other studies (Childers and Bennett

1967; Ellison and Heidinger 1978; Schaffer 1979)

also have shown largemouth bass to be effective

in the control off 2 individuals in largemouth basshybrid

sunfish populations.



Reproductive Isolation between a Hybrid Sunfish and

Its Parental Species


Attempts to produce backcrossed generations

both in the laboratory and in ponds were unsuccessful.

The reduced population

fecundity resulting from the low percentage of females

results in low recruitment of F2 hybrids and

consequent avoidance of overcrowded conditions.

Reduced population fecundity combined with

predation by largemouth bass results in essentially

no recruitment of F2 fish. Brunson and Robinette

(1986) found that largemouth bass can effectively

control F2 production in ponds, limiting F2 densities

to 35 fish/hectare. In ponds without largemouth

bass, the average F2 density after 2 years

was 2,142 fish/hectare.



Reproduction of Hybrid Sunfishes in Small Ponds

Percy W. Laarman

Michigan Department of Natural Resources

Institute for Fisheries Research, Ann Arbor, Michigan 48109

ABSTRACT: Reproduction of F1 hybrids of female green sunfish (Lepomis cyanellus) x male bluegill(Lepomis macrochirus) and female green sunfish x male redear sunfish (Lepomis microlophus) was determined in experimental ponds and compared with reproduction of bluegills stocked at similar rates in
the same ponds used in a previous study. The percentages of females among the stocked F1 hybrids were:
green sunfish x bluegill, 13%; green sunfish x redear sunfish, 28%. The green sunfish x bluegill cross produced 105 F2's and the green sunfish x redear sunfish cross produced 1003. Reproduction of bluegills was 279 times greater than that from either hybrid cross.


I can post more if you like. My 2 cents . The parental backcrossing question is uncertain as to a good answer. Very good PhD FS on both sides with mixed results. On the mBG X fGSF being sterile I disagree as a number of studies have resulted in F2s.


Last edited by ewest; 07/24/08 08:13 AM.