Ive read Mahi Mahi is the fastest growing fish, I would probably say a whale shark is the fastest
what fish grows the FASTEST?
- Thread starter miksha_
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Lol,despite the rather vague title that's the theme that I stuck with in my reply rather than naming off a bunch of fish that are not kept in the hobby.wowbut how about like fish i can keep
I made a quick figure to help out with this discussion.
As a general rule of thumb, fish grow very quickly from fry to sub adult and then their growth rate slows down. This is an adaptation that most fish possess in order to rapidly attain a size that makes it tougher for predators to catch/eat them (black line in figure below). I've drawn this growth curve with a slow start... the slow-start is characteristic of fry raised in a fish tank... they really take off once they can easily eat the offered food, which for most hobbyists isn't right out of the gate. This slow-onset would disappear for most fish if appropriate sized food/forage is readily available.
There is also a pattern whereby the larger the adult size of the fish, the faster it grows (red line). This is assuming that the fish is fed a balanced diet/feed and that water parameters (e.g. temperature) are kept within an appropriate range for the species.
Keep in mind this is a generalization across >27k species. Exceptions exist.
As a general rule of thumb, fish grow very quickly from fry to sub adult and then their growth rate slows down. This is an adaptation that most fish possess in order to rapidly attain a size that makes it tougher for predators to catch/eat them (black line in figure below). I've drawn this growth curve with a slow start... the slow-start is characteristic of fry raised in a fish tank... they really take off once they can easily eat the offered food, which for most hobbyists isn't right out of the gate. This slow-onset would disappear for most fish if appropriate sized food/forage is readily available.
There is also a pattern whereby the larger the adult size of the fish, the faster it grows (red line). This is assuming that the fish is fed a balanced diet/feed and that water parameters (e.g. temperature) are kept within an appropriate range for the species.
Keep in mind this is a generalization across >27k species. Exceptions exist.
This is not just for fish, but almost all complex living things. It is called the "s-curve of life". It is caused by many things, from the need to reach a size were you cannot be eaten and can reproduce, the complexity of getting all those weird parts to work when you're young, the fact that after a certain point, growing is difficult and harmful - a being twice as long will weigh 8 times as much because of the law of cubes, and it will need to eat 8 times as much. Look at trees, a year or so to go from a seed to a handful of leaves, and then BAM 15 ft in 2 years, and finally another 100 years to grow to 50 ft. It is just the way things are.
The fastest grower you can keep is probably RCS, as I am assuming you have a 75 gallon tank, and, as we all know, it is cruel to keep any fish in there.
I have never heard a growth curve called the "s-curve of life", but that doesn't mean someone didn't say it once! What I drew is a logistic curve. Most fish (and most animals for that matter) follow a positive asymptotic curve from birth -> maturity. Plants grow differently, as do humans.
This is only true of altricial species, like humans (and other mammals and birds).
Surface area to volume ratio does not strictly follow the formula you've outlined. You are on the right track though
Kleiber's Law is probably more applicable here. Simply put, the bigger the organism the higher its metabolic demand, which tends to put an upper limit on the size an organism in a given habitat can achieve. Growth in trees is limited by a number of factors (e.g. nutrients and water), but most importantly, by light due to competition. When competition for light is removed, rapid growth ensues. With trees, this often mean a growth spurt into the upper canopy of the forest after a couple of years of slow growth in the shade.
LOL...
