To paraphrase Inskip and Magnuson:

The primary determing factors for Muskie growth in a system with Nothern Pike was availability of Yellow Perch and were positively associated with July average temperatures. Yearling growth was negatively associated with abundance of Northern Pike. Relative condition of both speciaes remained high when both Northern Pike and prey species were plentiful after the first year.

This was a study on Escanaba Lake in Wisconsin. it would appear that the later (year 2 to 4) growth was related more to availability of prey. "Relative condition of large esocids was more positively associated with the harvest/effort measure of yellow perch abundance than was the relative growth of yearlings."

The temp in July data is limited, but by inference shows that there was only one year where higher water temps in July correlated with a slow gorth rate ( poor population of the right sized perch that year), and NO preiods where lower than average temps did NOT slow growth. Some good evidence, but not rock solid for sure. All the inferences above were population wide.

Best as I can relay the info, hope this helps.

fish on,
As a general population, no. There will be some variance obviously, but not a huge amount according to what I have read. The obvious genetic differences in strains has effect on the overall growth cap and rate (as is the inferior strain that was stocked in a few lakes around here) but the rate of overall growth is environmental in nature. Do Great Lakes strain muskies grow more rapidly? Not from the data I have seen, no. A 12 year old fish with good balance in the system will be about 47 to 48", just like the barred fish from this area. Will the Great Lakes Strain get larger? Also primarily an environmental question from what I have seen. Most of the muskies from Mille Lacs that I have seen are barred, and the growth rate and overall size of the fish there rival the Leech Lake fish, I think.

This is a good question for a fisheries manager. I will have my son ask his boss next week, and see what he says!

To clarify what I was trying to say:

'Natural selection' in fishes (if you accept this sort of thing) doesn't usually tend to follow the same lines as whitetailed deer, for example, where brute size/strength and superior combat skills/hardware as a result will determine what Buck's genetics are passed along if the herd size is at an ideal, or close to ideal level.

Fishes tend to lean toward survival rates of the spawn/young of the year, longevity, disease resistance, and other factors, as there is not the same competition for mates. Several males can accompany one female at the time she drops the spawn.

The AFS Special Publication 15 suggests that the first two years of a muskie's life will determing the growth rate impacted then and later by external factors such as prey availability, water quality and temps, competition with Northern Pike, etc.

If a spotted strain is stocked in a system where the primary forage is cisco, there are no rock solid indications the fish will grow longer or for that matter any faster than a barred strain in a perch based system; if both provide the number of prey class fish needed for good growth. There is some indication that the cisco based prey will allow for  heavier fish.

If  fish stocked at the same time have good availability of prey of either type, both at about 13 to 14 years should reach about 47 to 48".

Question:

If one is looking at a stocked CPR system with nearly no harvest (say 90 to 95% )  the biggest fish from there ever caught/fyke netted/boom shocked being is a spotted 52". The DNR determines that the limit on that water should be 52", does that necessarily increase the numbers of 52" 'cap' fish there?  If 95% of all the fish are released, shouldn't there have been at least a few representative supertankers caught if the system would support them? If the 52" year class was strong at say, 45", is now 20 years old, and harvest is minimal, why are not more 52inchers there? Why didn't that year class reach 56"?

Pelican Lake is a good example. When I first started fishing that lake in the early 70's, there was little stocking, and the strain was 'clear'. I caught a few really nice fish, in the 40# class, up to 54.5, and saw others in that class caught. Numbers were not all that great, but a solid fishable population. Clubs, the DNR, and others then stocked the bejeebers out of the lake during the 80's. Numbers increased overall to the point where I was able to put 32 legals in the boat there in 16 days in, most stockers.

Stocking has slowed there, and natural reproduction still is fair to good. The overall population is strong, with, IMHO, more mid 40" class fish by a long shot than there were in the 70's. BUT!

I don't see as many fish in the low 50" class. There are several other factors that need to be examined, like Native American spearing, the introduction of serious CPR, pike population balance, competition between bass, pike, and muskies for the prey there, and the decline of the bullhead population to near crash levels a few years ago. I would like to see a 50" limit on the lake just to see what happens, but am not at ALL convinced the fishing will actually get noticably better, or that the preponderance of the fish there that were in the heavily stocked year classes will ever reach that mark.

So many questions...

Isn't there a huge difference if the population is natural, the predator/prey balance nearly perfect, was not stocked, and isn't maintained?

What implications are there for put and take waters under this scenario, does the effective regulation simply make the lake CPR only without improving the overall numbers and size of the muskies? There are many more factors influencing the overall 'cap', or maximum size of adult muskies than just harvest.

Can we genetically engineer fishes? Sure. University of Michigan type 'hybrid' gills were stocked in a lake here, and rapidly took off. The fish are reaching 10" now, with way more body mass and depth than the native gills. Is that a good thing? Sure, as those fish are desirable for harvest. What would that answer be if bluegills were CPR only? Could the system sustain the population, without harvest, and remain healthy?

Hey Jlong or Doug J do you know of any work genetically engineering muskies in process now?

SO many questions..:)

The last work I've seen was by the Ohio DNR folks. The idea was to manipulate the X and Y chromosomes within the egg shortly after fertilization so the off spring would all be female. I think the effort was stopped because of lack of funds. Lack of funding is probably the biggest problem that studies like this have. Unless the fish have a direct commercial value (trout, salmon, etc.) it's hard to get much funding.

Lots of different variables in growth rates. Genetics, type of forage, abundance of forage, health of the fish, (would include the riggors of catch and release), length of growing seasons, water temperatures (not to hot and not to cold), water chemistry, various physical properities of the lake itself (cover, clarity, etc.), population densities, lake type, lake size, lake depth, relationships between shallow water and deep water, and who know what all else will effect growth rates. Lots of different factors, and no doubt many of these things change from year to year, and from lake to lake.

I doubt that we would ever know the answer to your question, if the fish would live long enough, and be in good health either could get big.

Doug Johnson