A study of the reproduction of Ezicymba buccata Cope in Vigo County, Indiana is based on changes in tuberculation in males, condition of the ovary, size and number of ova, and length frequencies of young-of-the-year. Levels of tuberculation are described and prove to be reliable indices of reproductive maturity. Temporal changes in the degree of tuberculation and condition of the ovary as well as changes in number of ova indicate a spawning period from the end of April to at least the end of July. Early in the spawning season both age group II and III males and females contribute most to the breeding population and the larger specimens spawn earlier. Projection of the growth in initially moderate sized ova and lack of abrupt differences in ova size in spring suggest that individual females in age group II spawn more than once within the spawning season. Most age group III males and females die shortly after spawning. Later in the summer (July) large age group I males and females probably breed. Study of ova size and number as well as ovary condition indicates two major spawnings, one in early May and the other in late June or early July. Monthly length frequency distributions of young also indicate two spawning peaks. Long breeding season, fractional spawning of age group II and the late summer spawn of age group I all are adaptive to streams with a shifting sand bottom.