A laterally compressed, slab-sided, spiny-rayed fish, it has a yellow-olive to silvery-yellow coloration along the back and sides that shades to yellowish-white along the belly and pelvic fins. Six to seven prominent, dark horizontal stripes along the sides are broken and offset above the front of the anal fin. The dorsal fin has two slightly connected lobes. Nine spines make up the first lobe and one spine and 12 soft rays are found in the second. The anal fin usually has 9 soft rays and 3 spines that are unevenly graduated. The first spine is much shorter than the other two, which are nearly equal in length. The mouth is scarcely oblique and the lower jaw projects slightly beyond the upper jaw.
Mississippi River, Maquoketa River, North Twin and Clear Lakes, Lake Manawa
Fish, insects, and crustaceans
1 pounds, 9 ounces - Lake Manawa, Pottawatamie County, April 1991 - Bill Campbell, Council Bluffs, Iowa
Yellow Bass live in natural lakes, reservoirs and the backwaters of large rivers. It prefers clear to slightly turbid water and a firm bottom substrate of sand, gravel, rock rubble and mud. It is uncommon in abundance, but widespread in the Mississippi River. It is abundant in Hartwick Lake, an impoundment of the Maquoketa River. At one time it was one of the most numerous game fish in North Twin and Clear lakes and may be in other natural lakes. Yellow Bass are found in Lake Manawa. This fish has historically been distributed in the many man-made lakes and water-supply impoundments in southern Iowa. Their origin in these waters is unknown, but probably resulted from fish transported from the Mississippi River.
Yellow Bass looks like White Bass, but it differs in many physical features. In Yellow Bass, the dorsal fin lobes are not completely separated, the first stripe below the lateral line is distinct and complete to the tail, and the base of tongue is lacking a tooth patch.
Yellow Bass reproduction in Iowa usually takes place in May when the water temperature is 60 degrees. Like White Bass, Yellow Bass move into tributary streams for spawning, but otherwise spawns over rock reefs and gravel bars in lakes. Spawning occurs in 2 to 3 feet of water and starts when a male and female pair off, swimming slowly about, releasing eggs and milt. Yellow Bass eggs are small, averaging about .031 inch in diameter, and are semi-buoyant. Fertilized eggs sink slowly to the bottom where they hatch in 4 to 6 days at a water temperature of 70 degrees. No care is given the eggs or sac-fry.
In Iowa, Yellow Bass grow fast, reaching an average of 4-inches in the first year, 7-inches the second, 9-inches the third and 10-inches at the end of the fourth year of life. Both sexes mature at age 3 and few adults live beyond 4 or 5 years. Being the smallest fish in the temperate bass family in Iowa, Yellow Bass rarely exceed three-fourths pound.
Adults are known to eat large numbers of their own larval-fry. Yellow Bass, like White Bass, feed in mid-water or near the surface during evening and early morning hours when natural light is at low intensity.
Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.