A few notes about Hybrid striped bass (HSB) and crappie. Also note that this is not an attack on B.Lusk's Nov. 04,2003 post, it is just additional information
that I hope you find useful.
1. Bob, in talking about the 35 acre lake near Lubbock, led me to think that since the lake had thousands of 4" -6" crappie, these sizes would fit into an 8" HSB's mouth. He said, "We calculated the average crappie in this lake would fit into an 8" HSB's mouth..... I assumed he was referring to the thousands of crappie sampled that were 4" - 6" long. Maybe not.
2. Anyway, FYI, I did some fishery science this week and came up with the following info.
8.25" HSB has a mouth opening of 23mm (0.9").
9" HSB has a mouth opening of 25mm (1.0").
13" HSB has a mouth opening of abt 29mm (1.14")
22 " HSB has a mouth opening of 43-46mm (1.7-1.8").
The vertical height(body depth or maximum body depth)of blk crappie in OH is:
4" long crappie is 31mm (1.2")high/wide
6" long crappie is 49mm (1.9")high wide
As can be seen, even a 13" long HSB would have difficulty eating a 4" crappie.
NOTE: fish mouth openings (gape)are somewhat subjective to measure. I did not forcefully stretch the mouth
open to the absolute maximum possible. But I did extend it open as to not damage the live fish and measured what I thought was a normal gape this fish would have in swallowing a fish.
DISCUSSION. I have no doubt that the HSB did do their intended job of getting crappie under control in the 35 acre lake Bob talked about earlier. I think the 8" to 10" HSB initially fed on smaller food items than 4" crappie. This is very feasable in a lake as big as 35 acres which could easily have a large complex food web that produces lots of appropriate sized food items for the 8"-10" size HSB. The HSB may have even fed on lots of crappie smaller than 4" (1"-2"). The HSB obviously grew and grew fast. When the fish were adequate size they could prey on the larger sized problematic crappie population, reduce the competition for food, allow more overall food to be available and remaining crappie&other fish would grow better.
The other feature of HSB and crappie that I think helps make them compatable is crappie (at least the larger ones) often tend to stay more in open water than say bgill. HSB frequent open water thus the two species come in frequent contact.
My point is when stocking a predator to thin a problem prey fish population make sure it will be able to immediately feed on SOMETHING so it can survive, grow and ultimately do the job you intended it for when you stocked it.
Long ago I made the mistake one time stocking fingerling LM bass to hopefully get an overabundant bgill (1.5"-3") population under control in a pond. Fingerling LMB needed to eat fry and 1/2" bgill but these were not present. Overabundant starving bgill were even robbing other bgill nests of eggs and fry. Newly stocked fingerling LMB had to survive on invertebrates which the overabundant bgill had also over eaten that food item. Very few if any of the fingerling LMB survived.
