July 14, 2011
By Doug Stange
One concept we have long used to get anglers to consider what they're doing when they're fishing a lure or a bait is this: The presentation moves we make have two parts, each with different purposes. First, we work our presentation to attract attention in order to get pike and muskie to move in close to check it out. Secondly, we manipulate the lure to trigger fish to bite.
Say we're working a jerkbait. We snap the lure then let it settle and stop. The snap is the attracting maneuver, while the pause usually triggers the fish. We might add twitches to the pause to further tempt (trigger) fish that have been called in.
At times attracting maneuvers also serve as triggering maneuvers. Say you're fishing a crankbait like the new Storm Kickin' Stik. Another option I have supreme confidence in is any of the thrumper-tail plastic swimbaits rigged on a jighead — or a prerigged model like the Storm WildEye Swim Shad. The realistic swimming movements of these lures attract fish that overtake the lure from behind and eat it — attraction becomes triggering. At other times, it takes a little hitch or pause in the straight swim to get fish to bite. Or, it might take pausing the lure to let it fall to get fish to finally react.
Vision is important, but anglers often overlook the importance of vibration in this process. My search for answers about how vital vibration can be lead me to Bluegills — Biology and Behavior, by Stephen Spotte. An in-depth and enlightening look at the biology of the bluegill proved a good place to find answers about how bigger fish respond to the vibrations that come from the things that live around them as well as vibrations from the lures and baits we use to fool them. In no other scientific discussion have I seen such detailed analysis of swimming movements and how those movements are sensed by fish with their lateral line.
Spotte talks about the hydrodynamic vortices generated by fish as they swim. He says: "The wake left by a swimming fish or other aquatic animal slowly attenuates (dies: my word), but not without alerting intercepting predators or prey of its owner's location and distance. These hydrodynamic 'trails' have been playfully called 'fish footprints.' The size of a wake depends on the size of the fish, but its morphology varies by species. If 'fish footprints' are indeed unique to species, and if they can be recognized and used to advantage by conspecifics or predators, they might better be named 'fish fingerprints.'"
Spotte says that trails remain distinguishable from the background noise for several minutes and may, in still water, remain detectable after 5 minutes. He mentions the process by which a muskie goes about finally feeding on a prey species — after saying that fish, without any visual cues can continue to feed effectively using only their lateral line, but they can not continue to feed effectively when the lateral line sense is blocked.
Spotte reports that a muskie feeds in two phases: "it skulks stealthfully toward its prey using the pectoral and caudal fins, then strikes quickly. The process involves vision for initial target detection, but the lateral line assumes dominance during the strike."
So, look at what we've learned. Fish happening through the "trail" of another fish can tell what fish species it is (fingerprint it) and perhaps even tell if it's swimming badly — wounded or injured. Likewise, predatory fish also don't have any trouble tracking a school of preyfish, sensing the school in larger context as it moves.
Surely this explains why some fish in deep water or where vision is limited suspend motionless for long periods. Like the starship Enterprise in space, sensors on alert, they're waiting for their lateral line sense to pick up the movements of prey species. Even without adequate vision, once the prey is moving they can track and strike.
Surely this is an explanation of what's at work when fish see and then track and strike a lure like a swimbait or a crankbait — or even a curlytail plastic. We know the lateral line sense is for close-quarters sensory perception having to do with low-frequency vibrations.
Once a fish sees something interesting it swims steadily toward the offering, gets behind it, and tracks it — or just swims up and stops. Once the lure or baitfish is in a zone a foot to inches in front of the fish, vision is important, but so too has the lateral line sense kicked in. Often the fish almost goes on autopilot, relying on the lateral line to make the final judgment about whether or not to eat the thing. Again, at times it's the lateral line, not vision that tells a fish to break off the chase and avoid the lure at the last second — or to go ahead and eat it.
The reason certain lures often so completely fool fish must be because the lateral line is getting feedback from something that feels perfectly natural as the fish closes in, traveling in or holding in the vortex of the lure. It has to look alive — and it better also feel alive.
Editor's Note: Bluegills — Biology and Behavior, by Stephen Spotte, is a publication of the American Fisheries Society, fisheries.org