http://www.lakescientist.com/lake-facts/fish/muskellunge/
" Muskellunge BiologyMuskellunge and northern pike many times inhabit similar habitats, and research in Minnesota revealed a few interesting findings. Muskie, in the absence of northern pike, tend to reproduce in the same shallow, weedy areas that would normally be dominated by northern pike spawning during the spring. However, in the presence of northern pike the muskellunge tend to spawn in slightly deeper water, yielding the more preferred habitat to the northern pike. The presence or absence of northern pike also appears to impact ultimate growth of muskellunge. Muskie inhabiting waters without northern pike rarely reach total lengths of more than 40 inches, while muskie in the presence of northern pike occasionally surpass 60 inches. Muskie spawning generally occurs when water temperatures are in the 50s (°F), and a 40-pound female can produce about 200,000 eggs. Muskie larvae eat plankton after absorption of their yolk sac and soon switch to a diet of strictly fish. Peak feeding periods for muskellunge usually occur when water temperatures are in the mid-60s. "