How Well Do Bass See Color ? How Does A Bass Lateral Line Work?

How well do Bass see? Bass are sight feeders, so water clarity and keen eye senses are critical for efficient feeding and normal development.

Interesting data from Chris Horton at Bassmasters explains bass have a large ocular lobe.  Big, protruding eyes provide broad peripheral vision.  Their only blind spots are directly below and behind. Bass experience excellent night vision by collecting more light than human eyes.  Since they’re ambush feeders, nighttime hours are productive foraging periods.  Vision is predominantly monocular.  To focus on an object, both eyes must see it simultaneously.  Bass may detect motion on one side, but to clearly identify the object, they must position themselves so both eyes peer in the same direction.

The most common question biologist receive regards a bass’ ability to distinguish color.  Without a doubt, they do! Retinas have cones and rods.  Rods help process black, gray, and white.  Cones interpret color and bass eyes contain numerous cones. Color is a product of light. Water clarity influences color spectrums.  If there’s a strong algae bloom or recent rain created murky conditions, light responds differently.  At night, bass rely on rods to see shadows and movements.  During new moons, increased ambient light in water dissipates quickly with depth.  In these conditions, darker lures have more contrast and are seen better.  On bright, moonlit nights, light penetrates deeper increasing recognition of colors.

Bass have great eyesight.  If water is exceptionally clear, they can see you in a boat.  I’ve had a fishing buddy joke about my bright colored shirt. Couple excellent vision with a radar-likelateral line that senses vibration and you see why bass are the top predator in your pond.

A bass’ lateral line is a row of pores that run along each side from the gills to the tail.  These lines are filled with water and nerve endings that are finely tuned to any water displacement (disturbance or changes in water motion). They help determine if vibration comes from prey or a predator, how close it is, how big it is, and which direction it’s moving; depending on how close the movement is to the bass.

Burns Phillips at bassfishingandcatching.com explains the lateral line is tuned naturally to detect subtle low-frequency (1-80 cycles) vibrations created by small prey such as minnows.  It’s an ear of sorts that detects vibrations resulting from water displacement.  This detection can occur at a significant distance if background noise is at a minimum. Bass associate specific sound wave patterns with specific prey.  A bass would not confuse water movement of your cell phone falling from your shirt into the water with that of a school of shad or even a single jumping shad.

Vibration is most important when water conditions limit visibility. After all, a bass is first and foremost a sight feeder.  Beyond four or five feet, bass hearing is much more important.  However, a vibration occurring five body lengths away may well arouse its attention and move it to investigate the source as a potential meal.  From such a short distance, the lateral line is deadly accurate and partly explains why even blind bass are able to feed and survive.

So it can be said that a lateral line, while playing an important role in feeding, is rarely the single determining factor for a bass striking fishing lures or prey beyond an area close to its body.  The lateral line aids in detection of water movement, arouses the bass’ attention, helps guide it closer to movement so it can see if the movement is food, and strike.

The lateral line sensory system is directional.  The inner ear is not. Both make it easy for a bass to pick up vibrations from lures like crankbaits.  For example, a rattle bait moving toward a bass from 40-50 feet away emits high frequency sound waves from its rattling shot and hooks.  The bass’ inner ear receives these sound waves, but is unable to determine the exact direction of travel.  Lower frequency vibrations from the lure wobble.  Pressure wavesare felt (heard) by its lateral line, thereby providing the bass a source of direction.

Even quiet water movement, like that emitted by soft plastic baits bumping rocks or stumps, can ping the lateral line and alert bass to the possibility of a meal.  Such soft lures probably more closely resemble sounds and vibrations made by natural prey than crankbaits or other hard plastic lures. In both cases, the bass will be aware something is out there, but may not consider it significant.  As vibrating or quiet lures come closer, vibration and sound reach a transition stage where both are strongly received.  The fish then combines its sight, hearing, and lateral line to determine location, direction, and identity of the lure.