Observations on the Biology of the Variegated Darter, Etheostoma Variatum (Kirtland)

Author Institution: Ohio State UniversityBetween June, 1964, and October, 1965, field and laboratory studies were conducted on the reproductive biology and larval development of variegated darters inhabiting Big Darby Creek, Pickaway County, approximately 25 miles southwest of Columbus, Ohio. These studies lead to the following conclusions. Prior to spawning, the darters migrate upstream from their wintering areas in the pools to the spawning riffles. The majority of the males become ripe when the water temperature reaches 40°F, whereas most females do not ripen until water temperature approaches 50°F. Spawning activity is confined mainly to the period from April 15 to May 10 when the water temperature is between 50°F and 70°F. Integration of field and laboratory data indicates that the eggs are deposited in the sand that accumulates behind rocks and boulders in the upper parts of riffles. Males, in a laboratory environment, exhibit both intra- and inter-specific territorial defense. The spawning behavior includes the typical darter ritual of following, nosing, and quivering movements, with the female choosing the spawning site. Eggs deposited in sand behind and between rocks and in fine gravel hatch in approximately 14 days at the prevailing temperatures. Fry, fed a diet of brine shrimp larvae, attain the juvenile stage within six weeks after hatching