Publications

The objectives of these cruises of the research vessel Musky II in 1965 and 1966 were: To determine changes in the fish population and environmental conditions in recent years; to determine if the geographic and depth distributions of certain species of fish in the summer differed from that in the autumn; and, to obtain much-needed information on the selectivity of experimental gill nets

The blue pike (Stizostedion vitreum glaucum) contributed about 12.7 million lb annually to the commercial production of fish in Lake Erie in 1915–59. Production averaged about 27% of the total for all species; in some years it exceeded 50%. The catch fluctuated greatly and was featured by a series of seven "highs" and "lows" during the 45-year period. The landings ranged between 2...

The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the...

No abstract available.

The food and food preferences of sea lamprey ammocoetes have not been investigated. The food of the larval American brook lamprey, Lampetra lamottei, in the Great Lakes region consisted mainly of diatoms and desmids according to Creaser and Hann. Schroll discussed the biology of feeding of ammocoetes of Lampetra planeri and Eudontomyzon danfordi in Europe. This report presents data on...

Experimental plantings of fin-clipped lake trout (Salvelinus namaycush) of various ages have been made in southern Lake Superior since 1952. The catch of planted lake trout by the commercial fishery was used to measure the success of stocking. Estimates of total returns were based on samples of 8.2 to 21.2% of the Wisconsin catches in 1955-62 and 36.4 to 46.8% of the Michigan catches in...

AN INVESTIGATION OF THE LARVAL STAGES OF THE SEA LAMPREY (Petromyzon marinus), which started in 1960, required a trap that could capture lamprey larvae moving downstream, and that would operate efficiently throughout the year. Sub zero temperatures in the winter and flooding during the spring were the most critical operational problems. Part of the trap was based on the principles of an...

Information on the biology of the freshwater drum or sheepshead (Aplodinotus grunniens) was collected in Lake Erie during a fishery and limnological study made by the Bureau of Commercial Fisheries in 1957 and 1958. Growth of the sheepshead in 1958 was slower than in 1927, and slower than the growth in most other waters. Males and females grew at the same rate through the 4th year of...

The large number of measurements needed to describe fully the characteristics of biological specimens and other objects has always been tedious and time consuming. The work can be done much more rapidly and with greater accuracy with a digital caliper recently developed by us. The digital caliper is a new electronic instrument built to measure objects precisely throughout the range of 0...

No abstract available.

Stomach contents were examined for 794 young-of-the-year (0-group) walleyes (Stizostedion vitreum vitreum) captured by trawls at 17 locations in western Lake Erie in June-November 1962. Food organisms were found in 92.5 percent of the stomachs. Food varied with geographic location and season of capture, but within areas and seasons, selection for certain species and sizes of prey was...

The results of tests of the biological activity of certain nitrophenols containing halogen are reported. Some of these are shown to be significantly more toxic to larvae of the sea lamprey (Petromyzon marinus L.) than to fishes. It is proposed that the death of lamprey larvae exposed to these compounds results from an acute hypotension (shock) with concomitant circulatory and respiratory...