Are there any fish that are easy to catch?

In “Do fish remember being caught with a hook ?” we looked at “Beukema’s learning theory” which states that fish remember being caught with a hook. This time, we will look at “Martin’s hypothesis” which states that there are certain fish that are good at being caught with a hook.

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The so-called “Martin’s hypothesis” was first proposed by American oceanographer John Martin, and states that there are some individuals that are naturally less cautious but more curious, making them good fish to catch.

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To verify Martin’s hypothesis, an experiment was conducted in Japan in 1992, in which Mozambique tilapia were placed in an experimental pond and fished.

Mozambique tilapia

The total number of Mozambique tilapia used in the experiment was 144. If the hypothesis that there are individuals that are easy to catch by fishing is true, then even if only the Mozambique tilapia caught by fishing are collected and fished again, a certain percentage must continue to be caught for the hypothesis to be established. The subject of the experiment was.

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So the researchers placed 144 Mozambique tilapia in a halved pond, caught half (72 fish) and placed them in a new pond, fished them a second time, and collected the fish from there and caught them a third time. They observed whether a certain ratio would be maintained.

However, contrary to expectations, the experimental results showed that out of the 72 fish caught in the first fishing trip, 51 were caught in the second fishing trip, and out of the 72 fish not caught in the first fishing trip, 51 were not caught in the second fishing trip either.

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The results of the third fishing trip showed the difference more clearly, that is, it was confirmed that Mozambique tilapia that were caught once were easily caught the second time as well, but those that were not caught in the first fishing trip were not caught well in the second and third fishing trips either. The number of individuals that were not caught well in fishing trips predicted before the experiment to be 18 individuals (12.5% ​​of the total) actually exceeded the number, which was 41 individuals (49% of the total), confirming that there are definitely individuals that are difficult to catch by fishing.

Finally, the researchers observed individuals easily caught by fishing and discovered that they reacted more strongly to food than other individuals. This suggests that individuals with a stronger appetite were more likely to catch fish. This once again demonstrates that greed is the root of all evil.

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However,  “Beukema’s learning theory” and “Martin’s hypothesis” had inherent limitations: the experiments were conducted in an artificial experimental environment without other fish competing for food  .

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Accordingly, in 2002, neighboring Japan conducted a rather crude experiment in which they selected four sections of 500 to 700 meters deep in a mountain valley in Hokkaido, which is rarely visited by anglers, and caught trout by fishing from sunrise to noon. They then shocked the remaining trout with electricity, caught them all, tagged them, and released them. After 50 days, they conducted a second experiment.

And 50 days later, when the researchers investigated the trout caught by fishing again, they found that the ones that were caught by fishing for the first time, tagged, and released were caught in similar ways to the ones that were not caught by fishing for the first time. This showed that both “Beukema’s learning theory”, which states that fish caught by fishing remember that experience and are therefore less likely to be caught, and “Martin’s hypothesis”, which states that some fish are inherently more likely to be caught, were not correct. Therefore, they concluded that observations in artificial experimental facilities are different from the actual state in nature, and that the habits of fish cannot yet be scientifically explained.

Of course, I, the author of this article, have no background in oceanography or ichthyology, just an individual who enjoys fishing. I also know that there is no perfect technique for achieving success in fishing.

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While most fishing experiences are a result of a coincidence of various conditions, often in different weather and environments, catching a fish is a matter of luck. I believe that the true joy of fishing lies in analyzing why a catch occurred, interpreting it in your own way, developing your own new hypothesis, and then testing it.

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Finally, let me share the main points of this article, which I’ve written in two parts. In my previous  article, ” Can Fish That Swallowed Hooks Survive If You Release Them ?” , I examined the results of releasing 77 trout that had swallowed hooks. The hooks decayed and were released from their bodies, and nearly 70% of them were re-caught.

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In other words, if “Beukema’s learning theory” and “Martin’s hypothesis” are correct, then it would be wiser to release fish so that they can grow properly in order to catch the big fish that anglers hope for. Even if the two theories are wrong, released fish can be caught again in the wild, so I expressed it this way to say that it would be good for us anglers to at least practice the standards for closed fishing periods and body lengths.