Even insect larvae sometimes destroy large numbers of muskellunge fry and fingerling. Age and Growth Growth of muskellunge can be highly variable, even among individual fish within the same water. When conditions for good growth are not present, stunting can occur. Muskellunge populations in Wisconsin have been found comprising fish that are nearly 20 years old and still less than 30 inches in length. As fish approach sexual maturity, differences in growth rates between the sexes become evident.
Females grow faster than males and often have greater potential of becoming much larger.
A generalized age and growth table is shown below, but remember these growth rates can be variable from lake to lake. Typically biologists use a scale sample to determine the age of a muskellunge, but scales can often be unreliable, especially for old fish. Muskellunge have been aged up to 30 years old using this technique. Unfortunately, the fish has be to killed for the cleithra to be removed. Taxidermists are often requested to remove the cleithra from trophy muskellunge they mount and send them to archives in Ontario for age determination.