Observations on the Spawning Habits of the Northern Pike, Esox lucius, in Northwestern Ohio

Abstract

THE location of large spawning runs of northern pike, Esox lucius Linnaeus, in streams tributary to Lake Erie, and the increased demand for predatory fish in Ohio's fisheries program, have awakened an interest in this species in Ohio. The pike was known in northwestern Ohio prior to 1900 and was present in great numbers, according to older residents. Many were taken in those days by means of spears, seines and pitch forks. Throughout this area their presence, only during the spawning runs, resulted in a lack of interest in the fish on the part of present-day sport fishermen. In the spring of 1949, 229 northern pike were netted from tributaries of Lake Erie and placed in a 5.33-acre pond at the St. Marys State Fish Farm. Also, 821 breeder pike from these streams were stocked in Nettle Lake, Williams County, Ohio, during the 3 years 1947-1949. Observations on spawning were made at the hatchery pond, at Nettle Lake, and at several streams in northwestern Ohio. Data on the incubation of eggs were obtained from eggs held in aquaria, in bell jars at the hatchery at the Toledo Zoo Aquarium, and in special screen hatchery troughs suspended in the abovementioned hatchery pond. Observations on the spawning runs of northern pike and on actual spawning seem to indicate that the object of the migration is to find marsh-like conditions for spawning. In Nettle Lake, and in East Harbor which is a bay of Lake Erie, northern pike spawned in marsh-like areas within the lakes even though tributary streams were readily accessible. No migration was noted in Nettle Lake except into and out of the marshes. Nine spawning groups were observed in the act of spawning in a marsh at Nettle Lake within 75 feet of the mouth of a tributary stream. Spawning runs up numerous streams of northwestern Ohio are observed every spring, many of them by Mr. Harold Wascko, Curator of the Toledo Zoo Aquarium. The facts obtained indicate that the chief factor in the control of this migration is the ice cover on the stream riffles. The open winter of 1948-1949 permitted free passage of the adults throughout the streams, and breeders were observed in early February in small tributaries of Lake Erie. No ditches seemed too small for the pike, provided that some vegetation or debris, with enough water to partially cover the breeders, was present. Males predominated in the early upstream movements, as shown by test nets, and females were more prevalent in the latter part of the run. Carbine (1942) found a similar difference in the migration dates for the sexes. Net catches on spawning runs indicated that the greatest movement of breeders occurred at night. All spawning groups were observed to spawn at a depth of 20 inches or less, with a majority of the spawning taking place in less than 10 inches of water-as compared to 6 to 18 inches found by Williamson (1942). Many large females were observed to spawn with their backs out of water. In most instances where spawning was seen, the water was clear and the eggs could