| Zusammenfassung: | Left pectoral spines were collected from 1,478 channel catfish (Ictalurus punctatus) taken in western Lake Erie during 1957, 1958, and 1959. Projected images of thin cross sections of the spines were utilized for age assessment and growth calculations. Spine radius measurements were found to correlate very closely with total lengths (r = 0.996) in a linear relationship. Calculated average total lengths in inches corresponding to each annulus were I--2.5, II--6.5, III--8.9, IV--10.6, V--11.7, VI--13.0, VII--14.3. At least 50 percent of the Lake Erie catfish are mature by the time they reach total lengths ranging from 10 to 12 inches. Data suggest that females mature at a somewhat smaller size than do males. Fifty percent or more of both sexes are mature by the end of their fifth year of life. No difference is evident between the length--weight relationships of the two sexes, nor does there appear to be any significant difference between the rate of length increase in the two sexes until the age of maturity is reached. After the fourth year of life, growth rates seem to decrease, with the male rate declining less than that of the female. Catfish from Lake Erie appear to be heavier per inch of total length than fish from either Oklahoma or the upper Mississippi River, but fish from the latter two areas seem to exhibit a somewhat greater annual weight increment after the second year of growth.
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