Texas Georgia Giant Experiment

Conducted in a small Ľ acre pond designed for kid’s fishing

Initial Conditions:

1) Stocking date: Dec. 3 '05

2) Water conditions

a. Total hardness: 136

b. Total alkalinity: 136

c. Ph 7.5

d. Muddy 62 degrees

3) 200 GG's 4 to 5 inches

4) 40 HSB 3 to 4 inches

5) Ten pounds of fathead minnows

6) 1001 Gambusia

Thesis: Evaluate the growth, aggressiveness, and sustainability of the GG in a small pond designed for Kid fishing.

Growth: Measure fish samples and record weight, length, width, and water temp along with photos on at least a monthly basis. Sample size will be two or three fish each time with the average of them representing the data entry.

Aggressiveness: Measure fish aggressiveness with monthly 10 cast comparisons with nearby CNBG and native BG ponds. The 10 cast test goes like this...make ten casts each with the same fly/lure or whatever in each of the three ponds and record fish caught and fish hits out of ten casts. Flies will be targeted specifically for BG and GG in order to avoid HSB, LMB, etc. Any LMB or other fish caught or hit will not count on the ten casts. The factor will be expressed as a % with each fish caught worth ten points and each hit on a cast worth 5 points.

Sustainability: This will be a subjective measure from the points of view of pond management efforts required and changes in the TGG, i.e. stunting, overpopulating, loss of hybrid vigor in successive generations, etc.

Conclusions (as of June 1, 2007):

1. Superior growth

2. Superior aggressiveness

3. Not sustainable with HSB as the primary predator

1) Growth:

The Data: The primary metric used to assess growth was the ave length of the fish taken from a sample size of 5 with the lowest and highest numbers thrown out and the remaining 3 fish averaged. Twelve such measurements were performed representing 60 fish over the 18 month period. At the 18 month point, the ave. fish came out 9.75 inches.

My comment: My standard for a nice BG is at least 10 inches. The TGG’s have reached that length very early in their second growing season. In comparable ponds, I have not seen 10 inch CNBG until generally the third growing season. Native 10 inch BG are not often found in my ponds. My conclusion is that the TGG growth is indeed superior to that of other BG in my ponds.

2) Aggressiveness:

The Data: The primary metric used to assess aggressiveness was an invented “Aggressiveness Factor” which represented the score of each type of fish during a 10 cast session using the same flies and at virtually the same times. Based on over 200 casts spread over the 18 month period, in all kinds of weather conditions, the TGG consistently scored higher than CNBG and native BG. The TGG proved to be 25% more aggressive than CNBG and 50% more aggressive than native BG.

My comment: The TGG is a super fun fish to catch on just about any tackle but a 10 inch TGG on a 3 wt fly rod is absolute, pure fun. The TGG does not hit typical poppers (e.g. Miss Prissy), in my pond, but prefers Gambusia imitation flies. The fish can be caught over and over again with very minimal conditioning observed.

3) Sustainability:

The Data: This metric, out of necessity, is largely a subjective measure. Trapping and fishing the TGG pond over the 18 month period provided some insight into the sustainability, but at this point it remains an open question. After one year, small Fx offspring began showing up in increasing numbers. Based on trapping results, I concluded that the HSB was a failure as the primary predator. That coupled with the fact that the HSB were completely hook shy made them of no value to me. This spring, when several 5 inch Fx offspring showed up, I decided to “fire” the HSB , remove as many of them as I can, and move to the LMB as the primary predator.

My comment: I believe that if things were left unchanged, i.e. HSB continued as the predator, the small pond would have become overpopulated with Fx offspring and also have an uncatchable predator in the HSB …both of those items are not acceptable to me. I’m confident that the LMB will solve both problems, but they themselves will also tend toward overpopulation. In order to keep a balance and minimize conditioning, LMB will have to be removed regularly. For me, that does not present a problem, rather a fun situation, but for some that may not be the case. Clearly, in the absence of management and with HSB as the predator, the TGG pond would be overpopulated with Fx offspring by the end of the second growing season.

Table 1. TGG Data Results

Date	Length, inches	Wt, ounces	Length GR, in/day Baseline .012	Wt GR, Ounces per day	GG AF, %	CNBG AF, %	Native BG AF, %	Feeding rates, pounds per day	Notes
12-03-05	4.5	.08	-	-	-	-	-		Initial stocking 200 GG, 40 HSB , and 1001 Gambusia
12-24-05	5.5	-	.048	-	-	-	-	Less than .25
02-03-06	7	-	.038	-	-	-	-	.25	Cold period
04-02-06	7.3	4	.005	.032	25	25	40	.25	Used #12 BH Zug Bug for AF, three fish average used for other entries, water very turbid. Coldest temps of the year late in this period.
04-28-06	-	-	-	-	65	35	15	.25	Used small grass shrimp/baby crawfish fly for the AF test; no camera available hence no entries made in the length or weight columns, but fish approaching 8 inches.
06-02-06	8.0	4	.011 (.020 cum)	-	25	50	35	.25	“Pop and drop” tandem flies; Miss Prissy & zug bug
07-31-06	8.0	-	-	-	10	20	15	none	BBBD fly. TGG pond highly turbid. Low activity.
10-01-06	8.8	8	.013 (.015cum)	027 (cum)	40 (ave 33)	10 (ave 24)	10 (ave 23)	none	BH WB. Visibility somewhat improved. Fx of two distinct sizes showing up now in traps.
12_15_06	9	9	.003 (.012cum)		-	-	-	none	Cold period. Water temps about 50 degrees
03_01_07	9.5	12			35	20	15	.25	Started feeding again for the first time since last summers muddy water. Fish respondng to feed. Removed 10 original HSB. Will replace them with equal number of smaller HSB later.
04-01-07	--	--	--	--	65	35	-0-	--	Replaced the 10 HSB that were removed with 10 F1 LMB. In addition, added 3 Pacu and 6 Tilapia to the pond. Note: Some 4 to 5 inch Fx showing up in the catches now.
05_29_07	9.75	12	.012 cum		38 cum ave	28 cum ave	19 cum ave	.25	SUMMARY

Notes: Each measurement is the average of two fish unless otherwise noted. Each measurement is documented by photos, which are available at the following link: http:www.meadowlakeponds.com/TGG.htm

GR= growth rate, inches per day

AF= aggressiveness factor expressed as a % based on 10 cast comparative sample (each fish caught = 10 points, each hit w/o catch = 5 points)

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