Tilapia Vs. Catfish in Central Kenya

catfush · Post by **catfush** » 16 Oct 2006, 16:49

Hi There,

My name is Casey. I am part of a developing community center near Kisumu and Kakamega in western/central Kenya (in case anyone knows it) and I need some, no wait, a lot of adivce from the experts...eh heh...that's you guys, right?

So we want to raise some kind of fish as part of a self sustaining situation but we are undecided about which kind to raise. We are totally new to this so there will probably be a lot of experimenting to do which means some fish dying, but we want to keep it to a minimum! I hope to get some advice about which of the two would be more suitable for beginners and which of the two would do better in an intensive environment. Since we are growing them for food we want lots of them, but the space is extremely limited. The pond itself will probably be round and about 10 feet from on side to the other. The depth is variable based on what is required for the fish.

I have a website address with lots of info about the fish themselves (http://aquanic.org/beginer/catfish/catfish.htm) but I am not so sure there is much info about the mechanics of necessary plumbing in a pond. However, before I go off getting a degree in catfish biology or Tilapia, I would like to know before hand which one sounds more appropriate to begin with.

Also, If anyone can point out a page with good explanations about how to construct an efficient pond, with instructions on how all the plumbing works, please let me know.

Thanks for taking the time to read my post.

Casey

MatsP · Post by **MatsP** » 16 Oct 2006, 17:39

I can't point to a web-site explaining the plumbing, but I can hopefully help a little bit with the basic idea of the plumbing (which isn't particularly hard, by the way).

The principle of pond filtration is the same as for any other aquatic system: You need to mak the waste-products of the fish as harmless as possible and you need to oxygenate the water so that the fish has some oxygen to breathe.

For the first part, you need a "biological filter", which converts ammonia and nitrite to nitrate - the latter being about 1000 times less poisonous to fish than the two former. The biological filter can be pretty low-tech, a "tub" of some sort that is water-tight and filled with small to medium stones of an inert type (i.e. they shouldn't be lime-stone or contain dissolvable minerals - stones found at the bottom of a river would be good in most cases, or ceramic material such as proper building bricks - coarsley crushed). A pump and some pipes to take the water out of the tank and pump it back in again is all you need. A filter to prevent any "big stuff" to get into the pump impeller would probably be a good investment.

There are more high-tech filters - but basic is better here, I think.

The second, you need some method to stir up the surface of the water and move the water around in the pond.

Luckily, you can pretty much do both with one single pump. Just let the water from the pump hit the water such that it causes the water to "move around" a lot. Or you could have a separate pump to pump air into the water.

For both purposes, the pump should be running 24hours per day [or as near as you can - stopping it for any long period of time will kill the filter bacteria and stop the oxygenation of the water].

Finally, the water will eventually be very rich in nitrate, whatever filter you build - there are two ways to solve that: Plants or "water changing" - the latter meaning removal of water and replacing it with "clean" water. The Plants method would involve having some plants either in the pond itself, or adding another pond through which the water flows that have plants that "suck up" the nitrate (which is a good plant fertilizer). I'm not sure what would be a good plant for this purpose, but local river/lake-plants would be best for the same reason as below...

I have one other comment: When choosing a fish, it would be a GOOD THING(tm) if you choose a fish that is already native in Kenya, rather than introducing a foreign one - some fish may escape and make their way into the local fauna, and although you're certainly doing this with the best intention, adding a potential predator to the local fauna is definitely a bad thing. [Think Australian rabits].

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Mats

racoll · Post by **racoll** » 16 Oct 2006, 17:48

Hi Casey.

The catfish in the link were the American channel catfish ().

It would be a big ecological no no to import and breed these fish in africa. The potential risks to native species would be enormous.

Native catfish species such as the barbel () would be more appropriate.

I imagine this species would have a lower fecundity than the tilapia, but would probably be able to tolerate poorer water quality (as they can breathe air).

I couldn't tell which is better though.

Sorry I can't help you any further.

Good luck with the project though

MatsP · Post by **MatsP** » 16 Oct 2006, 18:02

There is a link for C. gariepinus breeding on the original posts link too - it takes you to this one:

http://cdserver2.ru.ac.za/cd/catfish/catfish/

It has a section on pond design too:
http://cdserver2.ru.ac.za/cd/catfish/catfish/cat82a.htm

Other sections describe water quality and other such things to think about.

Note that Clarias are light-sensitive, so you may need a shade/roof (or trees) over the pond to make them "happy".

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Mats

MatsP · Post by **MatsP** » 16 Oct 2006, 18:07

One further aspect: Food - what do the fish eat, how do you get that food to them, and what are the conditions that are needed to store the food.

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Mats

Post by **Marc van Arc** » 16 Oct 2006, 18:25

A long time ago I heard a story from someone who regularly came in Africa. This person said that some religions forbid native people to eat scaleless fishes, which would be catfishes. He told that people were starving while a few 100 metres away Clarias spp. were abundant. Perhaps it's just a tale; I've never been there.
This person now lives in Brazil and I can't contact him anymore. But you might want to check it before you start breeding catfishes.

Post by **corybreed** » 17 Oct 2006, 01:04

Marc,

I the Jewish faith fish must have scales in order to be Kosher.

Mark

sidguppy · Post by **sidguppy** » 17 Oct 2006, 08:52

if that's the case, expect the Muslim faith to have the same rule, except that it's called 'Halal' (the same as kosher).

if catfish are 'Haram' you can expect Muslims to refuse them; and Africa's population is about half Muslim and growing......

catfush · Post by **catfush** » 20 Oct 2006, 12:07

Hello again,

Thanks for the reply to my message and for the links. I went to the one about african catfish and copied over the information. Now I have to try to sort through it all.

I'll let you all know how it goes. It seems a deffinite benefit over Tilapia that catfish are able to breath air. This morning someone raised the idea of possibly using carp but I have not even begun to look into that kind of fish yet. Guess I'll get to it sometime.

Thanks again.

Casey

MatsP · Post by **MatsP** » 20 Oct 2006, 12:45

Yes, catfish can breath athmospheric oxygen, which for example Tilapia are unable to.

Carp is a good alternative as they are tolerant of great variety of temperature and also low oxygen levels caused by high temperature and still water. See http://filaman.ifm-geomar.de/Summary/Sp ... .php?id=79 for some more info. There are some drawbacks with this species as well as any others... One being it's verocious apetite for submerged vegetation...

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Mats