early fish observations

[Deep Lurker]

Lets say you live somewhere that does not have a subtropical climate suitable for tilapia and haven't the inclination or money it takes to build a climate controlled system to house them. There is comparatively little info available on temperate climate fish for aquaponics. Much of it is musings and hypothetical, better than nothing but it leaves the topic pretty murky. It can be difficult or impossible to get these fish from a dealer as well. So what does one do? You do things the old fashioned way and go catch them yourself. As a kid I remember quite a few people would keep catfish or bass whatever they had caught recently in old bathtubs or stock tanks until they were ready to eat them, sometimes for extended periods. I see no practical reason why this can’t be done for aquaponics. I should note that there may be laws about this sort of thing in some places, so its up to you to find this stuff out and decide if you want to go this route.

First things first, decide on what kind of fish you want. Catching something local means that it ought to be adapted to your climate conditions. You should also consider where you are going to keep them vs. where they live on their own. Rainbow trout for example like clean moving water to do well and may not like a small relatively still tank (not to say it won’t work, it’s just not optimal). Some fish are easier to feed than others. It may be harder to pellet train an ambush predator than an opportunistic omnivore. There are many other factors to consider but one I don’t see often is do you actually like to eat the fish in question. If you don’t, the other stuff really doesn’t matter.

I won’t go into how to actually catch the fish in question, you can figure that out on your own. What I will say is you need to minimise the stress on the fish. Obviously a barbless hook is a good idea, maybe one that is a bit big to help prevent it from getting swallowed. If they do swallow it, well, you have dinner. Handle them as little as possible and have a bucket full of water to keep them in until you get them home. You will need, not want, NEED a way to aerate the water in the bucket or they won’t last an hour. A battery power air pump with a weighted airstone is a fairly inexpensive and effective way to do this. It’s a good idea to keep the temp in the bucket stable so keep it out of the sun. Once you have your fish take them home and quarantine.

There is plenty out there about quarantining but I have a few observations. Yellow perch, for instance, are very flighty and startle easy. To help counter this try quarantining them inside where they can see motion regularly to help desensitize them. When quarantined outside they would startle at the slightest noise or vibration sending them darting frantically around the tank and hitting the sides at full speed (some actually killed themselves this way). Even inside they still stress easy and will get infections easily. Just assume they will get an infection and take steps accordingly. Obviously frequent water changes. I also treat the water with salt, pimafix, melafix, and acriflavin and continue to do so for a week or so. I do this from day one, they are fairly mild remedies and act as a simple prophylactic to most stress induced infections with little negative impact on the fish.

Quarantine is also an excellent place to pellet train. In the big tank it’s hard to tell if they are actually eating of just biting and spitting the food out. Yellow perch seem to be a bit particular about pellets. They hang out near the bottom so they don’t like to eat from the surface. They also don’t seem to like to eat directly from the bottom. It’s been weeks and mine still have to be really hungry to go for the pellets but they are at least biting on them. Soaking the pellets helps, as does mixing them with something they love like worm pieces or pillbugs. Yellows seem a bit cautious as eaters; they like to watch and observe a potential meal. Bluegill on the other hand are not picky or cautious, they see motion anywhere and they go for it and decide if they like it once they bite. They take to pellets with only a little encouragement. I would like to mention at this point that mixing bluegill and yellow perch may not be a great idea. Bluegill are very aggressive eaters and will eat every bit of food they can before it gets down to the more tentative yellow perch.

[Lloyd Booth]

Catfish are well studied, and commented on here in the AP community. They are Omnivores, and available for shipping to all 50 states. If you wish to catch your own, they are also available in almost all states. I am planning on using catfish, and my state (WA) does require a permit to ship them. However my local farm store carries fingerlings as well, and they will be my source.

Catfish can handle cool to cold weather, but like all fish that can, they don't grow in cold water, they just exist. In hot weather, the water temp needs to be below 80 degrees F or the water will not hold sufficient oxygen even with a massive air stone [just physics, but well studied].

Another fish that tolerates cold weather is carp, whether you want high end carp like Koi, or average carp like goldfish, both will tolerate the cold temps of winter, but not freezing. At a recent conference, Sylvia pointed out that good Koi sell for more than a $1000 a pound when they are over a foot in length, but not for eating, and I have no idea how small or inbred the market is for big Koi.

>>Bottom Line: there are lots of cold tolerant fish, that do not require babying, ask on the forums for more advice.

[Keith Rowan]

i've seen quite a few posts on this forum referencing chemicals for treating ap systems, most that you find at your local petsmart are NOT intended for fish you plan on eating...

there are only a few "approved" medications for aquaculture (raising fish for food!), and i'd even be hesitant about using most of those..some require a license to hande

in many states it's illegal to transport live fish without a license, or to transfer from one (public) body of water to another..(even if the other bow is your own pond)