Feeding Habits of Bass
by Herb Allen
According to Fisheries Biologist Rich Cailteux, bass have a greater field of vision than humans and can see in all directions except directly behind or below.
"The distance a bass sees will depend largely on water clarity," Cailteux emphasized. "In low light conditions, they rely on other adaptations that sense sound or vibrations."
Using "inner ear" structures and a highly developed lateral line system which occurs as a series of sensory pores along each side of the fish, a bass will respond to water movement by detecting the vibrations or sounds made by prey.
This is a probable reason why rattling-type lures do so well in lakes where water clarity is poor.
"Largemouth bass can also detect odors, but their use of smell or taste is not understood and probably used less for feeding than other senses," he stated.
Studies have shown that bass feeding habits change as they grow. After absorbing the yolk sac that supplies nourishment to the developing embryo (13 to 15 days after hatching), advanced bass fry begin to feed continuously on zooplankton, microscopic organisms that live suspended in the water.
As they grow larger, aquatic insects and small fish become more prevalent in a bass diet, and by the time a fish reaches two or three inches in length (generally by late summer), they may feed almost exclusively on small fish and such larger crustaceans as grass shrimp and crayfish.
"High mortality can occur during this life-stage due to a shortage of suitably sized prey," Cailteux said. He goes on to add that bass feed predominantly on such things as threadfin shad, gizzard shad, bluegill, shellcrackers, golden shiners, smaller largemouth bass, and a variety of other small fishes.
Being opportunistic feeders that consume whatever is most readily available--frogs, salamanders, snakes, mice, turtles, and even birds are among items occasionally found in bass stomachs.
Bass swallow organisms whole instead of biting off pieces, thus limiting the size of the prey they consume. Any prey having a body depth less than the diameter of the bass's mouth may be consumed.
A bass will grasp its food any way it can, but usually tries to swallow other fish head first, thus forcing the dorsal fin of the prey to lie flat when swallowed.
Cailteux pointed out that bass can be an "ambush predator" which lies in wait for prey to swim by.
"This type of behavior takes place when vegetation or other structure is available," he stressed. "In open water situations, bass become active pursuers and, because of a streamlined shape and muscular body, allows them to outswim their prey."
Although bass are usually considered to be solitary predators, they frequently gather in schools to "round up" such prey as shad.
Feeding behavior of bass can be triggered by hunger or by reflex when something is introduced into its immediate environment. Anglers can trigger this reflex feeding response by presenting a lure within its field of vision.
Adult largemouth bass do not feed continuously, said Cailteux. "Once a meal is ingested, it may not feed again for hours or days depending upon the size of the prey that was eaten. In general, larger bass eat larger prey, so the time span between meals is usually longer."
