Looks like I've been pretty wrong about what's a harmless fast for a fish?

[Viktor Jarikov]

This morning I came across The Fish Doctor on youtube, who has loads of good, informative videos, which is highly commendable. However, in the first video I saw, what struck me is this statement written below the video in the comments:

"From time to time, fish can go off feed, sometimes for unknown reasons. It is important to start giving nutritional support within 1-2 weeks if fish stop eating."

Perhaps ignorantly, I've always thought based on my superficial experience that even a few-months-long fast is acceptable or nothing to worry too much about, while an ill fish's organism is working on its issues.

On the other hand, when weaning fish off live foods, I let them fast for long times too, even up to 4-6 months, as I've done with two 6"-7" juruense catfish.

Thus, when met on PCF and MFK with questions of how long a fish should / can be fasted, I'd not hesitate to tell them my opinion.

Yet, I must assume that The Fish Doctor surely must know incomparably more about this than me and hence I should correct my thinking.

I am wondering what others think of this, especially our resident PCF experts and professionals?

[Bas Pels]

I would think this guy is interested in selling his services. And thus he needs clients

Fish from lakes, which are highly stable, cannot go long without feeding. Mbuna from Lake Malawi will not survive starving for a fortnight. At least, that is what I´ve been told. This would imply catfish from these lakes will aldso be sensitive towards starving (although a bit less, as Mbuna are grazers, they eat the whole day, and the accompying catfish are more predatrory)

But fish from rivers, which are far less stable, find meager tines in nature. The Amazon forest is a dry area for a few months each year, and in this period most fishes will not find much to eat. So they must be able to survive starving for a few months. Or go extinct - and they did not die out

However, for large catfish, living in the River amazon itself, I wonder whether the above applies fully: The Amazon River might, due to its large size and slow flow, be regarded as a very long lake. Predators don´t eat every day, but predators in a very stable environment will eat at least every week or so

However, if experience has tought a mopnth without feeding is acceptable, I think experience is more important than expectations