Springfield — Placed at a buffet of various fishes, the largemouth bass appears to have a surprising preference.
Old ‘big mouth’ likes to dine on old ‘big head.’
This we learn from a unique study led by the Illinois Natural History Survey and the University of Illinois, which tested the bass’ dietary decisions by placing it in experimental pools with shad, bluegills, shiner and two species of Asian carp – the bighead carp and the silver carp.
The bass ate more bighead carp than any of the other species of fish.
INHS graduate student Eric Sanft presented a review of the study, titled “Vulnerability of Juvenile Asian Carp to Predation by Largemouth Bass,” during the Midwest Fish and Wildlife meetings held recently in Indianapolis. Sanft, who did the research while working under Dr. David Wahl of INHS, was particularly interested if largemouth bass had a leaning toward one species of Asian carp or the other. As suggested, he found that bighead carp are more susceptible to predation.
Efforts to stem growing Asian carp populations have led many biologists and scientists to look at predator fish as a source of control. An ongoing study at Western Illinois University has been looking at blue catfish as a possible predator that could feast on Asian carp and help solve the over-population problem.
According to scientists, there are no North American fishes large enough to eat an adult Asian carp. White pelicans and eagles, however, have been seen feeding on juvenile or smaller adult Asian carp.
It had been suggested that largemouth bass have been observed feeding on small juvenile Asian carp, and many other native predators probably also feed on them before they grow too large. However, Asian carp produce many offspring which grow quickly.
INHS surveys have shown that in some stretches of the Illinois River, at least seven native fish are preying on Asian carp. Yet these same stretches have some of the highest densities of silver carp recorded anywhere in the world.
The fact that bass seem to prefer bighead carp to silver carp may help to explain why silver carp have been more successful at colonizing in the Illinois and other Midwest rivers, Sanft pointed out, adding that young silver carp appear to be a bit more “street-smart” than young bighead carp.
Bighead carp and silver carp are also invasive throughout much of the Mississippi River system and are threatening to invade the Great Lakes.