So I feel like starting a fight.... *ahem* intelligent discussion about the myth that fish grow to the size of their enclosures.
Now, I know that, as that statement stands, there's no logical backup for the theory. Just because you keep an oscar in a 10 gallon tank, does not mean it will stay 3 inches for the rest of its life.
However, in the wild we do see evidence of animals, mostly fish and reptiles, generally not mammals, adapting to the availability of some limiting resource, a common one being food. I was talking about this with a fellow fishkeeper who has been out of the hobby for some 15 or 20 years, and he is constantly amazed by the advancements that have been made in the hobby (i.e. I keep my betta in a 10gal community setup, and it works great. Apparently 20 years ago, this was unheard of.) He posed an interesting question, that in the wild, how do you suggest solid adult size for a fish? Take a largemouth bass for example. How big is an adult bass? It depends on a lot of things, a big variable being area of the country, among other things. Up here in New England, a 5lb bass is a pretty good catch. I'm no great fisherman, but I call it a successful day if I can land a few over 12-16". Now, a 14" largemouth and a 24" largemouth can probably both be considered adults. Go down south, and you'll see much bigger fish being caught on a regular basis. This could be attributed to a longer growing season, and more time to eat and get big and healthy. Would this be an example of a fish adapting to its surroundings? I would say yes. Fish that don't have as much time or as much available food to grow, stay smaller within a reasonable range. Is that to say that the 14" bass is unhealthy or not thriving? I don't think so.
Now, whether this is carried over to the home aquarium is what is under question. Since most of us keep tropical fish, they eat year round, there are no growing seasons/dormant seasons. However (and I'm not suggesting anyone starve their fish in an effort to stop growth), by paying closer attention to diet in our fish, is it possible that there is a certain limit to how big a fish will grow in the home aquarium? There is a lot of evidence showing that many species of fish grow bigger in the wild than they ever have in captivity. Does this mean we are screwing something up along the way, or is the fish responding and adapting to its conditions?
Just some thoughts I've been having, I'm not advocating drastic changes in fishkeeping for anyone, but I am curious to hear what opinions people have on the matter. Thanks for reading.
Now, I know that, as that statement stands, there's no logical backup for the theory. Just because you keep an oscar in a 10 gallon tank, does not mean it will stay 3 inches for the rest of its life.
However, in the wild we do see evidence of animals, mostly fish and reptiles, generally not mammals, adapting to the availability of some limiting resource, a common one being food. I was talking about this with a fellow fishkeeper who has been out of the hobby for some 15 or 20 years, and he is constantly amazed by the advancements that have been made in the hobby (i.e. I keep my betta in a 10gal community setup, and it works great. Apparently 20 years ago, this was unheard of.) He posed an interesting question, that in the wild, how do you suggest solid adult size for a fish? Take a largemouth bass for example. How big is an adult bass? It depends on a lot of things, a big variable being area of the country, among other things. Up here in New England, a 5lb bass is a pretty good catch. I'm no great fisherman, but I call it a successful day if I can land a few over 12-16". Now, a 14" largemouth and a 24" largemouth can probably both be considered adults. Go down south, and you'll see much bigger fish being caught on a regular basis. This could be attributed to a longer growing season, and more time to eat and get big and healthy. Would this be an example of a fish adapting to its surroundings? I would say yes. Fish that don't have as much time or as much available food to grow, stay smaller within a reasonable range. Is that to say that the 14" bass is unhealthy or not thriving? I don't think so.
Now, whether this is carried over to the home aquarium is what is under question. Since most of us keep tropical fish, they eat year round, there are no growing seasons/dormant seasons. However (and I'm not suggesting anyone starve their fish in an effort to stop growth), by paying closer attention to diet in our fish, is it possible that there is a certain limit to how big a fish will grow in the home aquarium? There is a lot of evidence showing that many species of fish grow bigger in the wild than they ever have in captivity. Does this mean we are screwing something up along the way, or is the fish responding and adapting to its conditions?
Just some thoughts I've been having, I'm not advocating drastic changes in fishkeeping for anyone, but I am curious to hear what opinions people have on the matter. Thanks for reading.