Between 66 % and 99% male depending on the study. Most around 95%. it is thought that the one study with 66% males was due to non pure GSF stock. The real interesting part is the % male depending on the type of lepomis cross. The seminal study was done by Childers.


HYBRIDIZATION OF FISHES IN NORTH AMERICA
(FAMILY CENTRARCHIDAE)
by

W.F. CHILDERS
Illinois Natural History Survey
Urbana, Illinois
U.S.A.


4.1 Sex Ratios of F1 hybrids
Sexually mature F1 hybrids were collected from each population and sexed. Of the 10 kinds of viable F1 hybrids, seven were predominately males (RB, BR, and BG were 97 percent males; WG were 84 percent males; and RG, GB, and BW were approximately 70 percent males), two were approximately 50 percent males (GR and RW), and one was predominately female (GW was 16 percent males). Ricker (1948) determined the sex of 428 BR F1 hybrids in Indiana and found them to be 97.7 percent males.

In this paper R refers to red-ear sunfish, B to bluegill, G to green sunfish, and W to warmouth. Matings between individuals of different species are designated to P1 crosses and the resultant hybrids are designated as F1 hybrids. F2 hybrids are those produced by mating an F1 male with an F1 female. The P1 cross of a male bluegill with a female green sunfish is designated B × G and the resultant hybrids are designated BG F1 hybrids; GB F1 designates the reciprocal hybrids.


4.2 Reproductive success of hybrids
The reproductive success of each of the 10 kinds of viable F1 hybrids was investigated in one or more ponds. The occurrence and abundance of F2 hybrids were determined by seining, trapping, shocking, poisoning or draining the ponds after the F1 hybrids were one or more years of age. RB, BR, and BG failed to produce abundant F2 generations when in ponds which contained no other species of fishes. In contrast to these results, BR F1 hybrids produced abundant F2 generations in two ponds in Indiana (Ricker 1948). The other seven kinds of F1 hybrids produced abundant F2 populations when stocked in ponds containing no other fishes. Three of the seven kinds of F1 hybrids which produced large F2 populations when stocked in ponds containing no other fishes were also stocked in ponds with largemouth bass. RG F1 hybrids and GB F1 hybrids, when stocked with largemouth bass, produced only a few F2 hybrids. No F2 hybrids were found in the pond stocked with BW F1 hybrids and largemouth bass. WG F2 hybrids and GW F2 hybrids were stocked in ponds containing no other fishes. Both of these F2 hybrids produced large F3 populations.
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Last edited by ewest; 04/24/11 07:15 PM.