Spawning Behavior and Fecundity of Lampreys from the Upper Three Great Lakes
Five species of lampreys are found in the upper three Great Lakes. All species require certain physical factors for successful spawning such as suitable bottom substrates, water velocities, and temperatures. Nest construction (usually started by males) and spawning behavior are similar although some differences exist. In sea lamprey an average spawning act lasts about 2–5 s and is repeated every 4–5 min; generally nesting is monogamous with little polyandrous nesting (1.2–5.0%); average egg production is about 60 000 eggs. An estimated 86% of the eggs of sea lamprey are not deposited in the nests; however, the fertilization and survival of eggs deposited in the nest is high and may approach 90%.Key words: Petromyzon marinus, Ichthyomyzon unicuspis, I. castaneus, I. fossor, Lampetra lamottei, spawning requirement, nest construction, fecundity, nest productivity, water temperature