Fish rely on their senses to get around their world and to tell them what they should eat and what they should run away from. They don’t perceive their surroundings quite the same way we do, though, and that can make it a little more of a challenge to trick them into biting our hooks. A better understanding of how fish work will give us a little more of an edge.
Fish vision is different from ours. In order for them to see well underwater, their eyes don’t function like mammal eyes — but they do function quite well.
Most fish see a lot better than we think. And they don’t just look at things under the water; they also look at things above the surface. A crab on a mangrove limb, a bird flying overhead, a person standing on the bow of a boat — they see it all.
Fish are also very tuned in to small differences in their prey. When they’re heavily focused on a certain size of baitfish or shrimp, they may ignore any that don’t fit the mold. Spanish mackerel that are mowing through a school of inch-long whitebait fry won’t even look at a half-ounce spoon. Snook that are crushing three-inch shrimp around a light on an outgoing tide will just watch a five-incher drift past.
There has been a huge increase in the number of ultra-realistic lures on the market recently. You can buy a plastic shrimp, crab or baitfish that looks exactly like what it’s imitating — to us. What does a fish see? Most likely, a chunk of lifeless plastic. Until it moves right and triggers a strike reflex, it probably doesn’t look at all like food from their perspective.
Do fish see color? Of course they do. How much does it influence their decision in whether to eat something? That’s hard to say. Does a fish eat a fire tiger lure because it looks deliciously edible, or because he can see it better against the dim background and it’s just more noticeable?
What we can say for sure is that fish react to color and to motion, and the combination of those things can make them eat your bait or just watch it swim past. However, vision is not the most important sense to a fish. That makes sense in a world where suspended silt can suddenly reduce your sight to zero.
Hearing is nothing more than the detection of vibrations in air or water. Sound moves much faster through water. Did you realize fish have ears? Not like Dumbo, but inner ears. In some fish, such as catfish and carp, these inner ears are connected to the swim bladder. The air in the swim bladder amplifies the vibrations coming through the water. Sharks may also rely on hearing to locate prey. But overall, ears are less important to fish than lateral lines.
Vibration & pressure
For most fish, this is the go-method for detecting what’s happening. Water is an incredible conductor of vibrations, and the lateral line is an excellent system for detecting them.
From a fishing perspective, being able to trick a fish’s sense of vibration is more important than tricking its eyes. That means that how an artificial lure moves in the water matters more than what it looks like. Any lure you use — a soft plastic, a spoon, a topwater plug, a spinnerbait — sends out vibrations as you move it through the water. Fish feel those vibrations and decide whether or not they’re interested long before they ever see or smell it.
Choose carefully what kind of vibrations you’re sending out into the water. It’s easy to make too much of a ruckus and scare fish with lures that make as much noise as a predator. That’s why a Rat-L-Trap or spinnerbait is not usually the best choice for fishing calm and shallow water. Save those for deeper, murkier water.
But you do want fish to be able to feel something out there, so something like a thumping paddletail provides it and gives a fish something to track down. If a lure makes too little sound, it won’t draw fish from a distance. Too quiet is better than too loud, but neither is great.
Smell & taste
For some fish, this is a minor sense. Seatrout are a good example. They can smell, but they find food primarily by sensing vibration and then using sight to hone in their attack. That’s why a soft plastic lure under a popping cork is so effective on them.
But other fish use scent far more. Redfish are in the drum family just like seatrout, but their techniques for stuffing their bellies are very different. Reds have an acute sense of smell and often rely on more than their other senses. When you think about their diet, which is heavy on quiet burrowers like worms, the reasons for a powerful sniffer are clear.
All fish can taste, and some of them are mega-tasters. Catfish, for example, have taste buds scattered all over their bodies and heavily concentrated on their whiskers. Something that tastes like food works better because it gives you more reaction time. If a bait tastes like plastic, fish will spit it out quickly. But if it tastes like it might be real food, they’ll at least hold it longer.
For fishing, think about it this way: If your lure smells or tastes like food, it’s not guaranteed to help — but it will never hurt. Thus the popularity of Pro-Cure and other scents.
While this is hardly enough information to satisfy a true ichthyological curiosity, it’s probably more than sufficient for most of our readers, who are more interested in fishing than fish. But it’s never a bad thing to know a little more about your quarry — it will make you a better hunter.
Robert Lugiewicz is the manager of Fishin’ Frank’s Bait & Tackle, located at 4425-D Tamiami Trail in Charlotte Harbor, and a co-host of Radio WaterLine every Saturday from 7 to 9 a.m. on KIX 92.9 FM. Call 941-625-3888 for more information about the shop or for local fishing tips, or visit them online at FishinFranks.com.