Food and Feeding Habits of Gizzard Shad in Pool 19, Mississippi River

Abstract

Examination of 344 of 1,368 gizzard shad captured mainly with gill nets during 1966–67 showed that intensive feeding began in April or early May and ended by early September. There appeared to be little correlation between diurnal activity and food consumption. Fingernail clams (Sphaeriidae), sand and unidentified material were the most abundant items found in larger gizzard shad. Larger shad captured in open waters consumed a larger percentage of bottom organisms, particularly fingernail clams, than did smaller shad. Comparison of numbers of fingernail clams (less than 5 mm long) in bottom samples versus volume of sphaeriids consumed by shad in the same areas revealed greater consumption in open water habitat where clam populations were highest. A significant weight difference at a given length was found between shad captured during summer from shallow water versus those from open water habitat, presumedly correlated with feeding habits.