Stirring up the pot ... Live Food and Parasites?

[JeffreyRichard]

This is coming from a response to my post regarding raising daphnia ... I heard it quite a bit in the past (particularly around Blackworms) ... looking for thoughts/ideas/debate, etc ...

Live food (general) are risky because they (can) carry parasites ...

Now, I understand that Tubifex worms can be risky, but isn't it because the worms themselves come from polluted sources? If so, isn't it more accurate to say these foods are TOXIC to fish, as opposed to carriers of parasites?

OK, how about daphnia ... is it inherently dangerous to feed live daphnia to discus if the daphnia are grown outdoors? I'm not seeing the logic with this ... a carrier of parasites must be exposed to an infected source to become infected themselves. If I grow daphia outside in tubs/barrels, I not seeing where the parasites come from to infect the source. I suppose if a bird were an intermediate carrier of something like tapeworm, and then deficate in the tub/barrel, there is a possible source. But does parasites such as hexamita, spirolnuclosis, etc originate with daphnia and then get passed on thru the food chain? I'm hoping Al or someone with a scientific background can answer this ...

My FEELING (not a factual statement ... please note) is that the fear of live food started and has propogated through the general paranoia of losing fish ... not wanting to chance the "unknown" ... I think the bigger risk is that live food may carry toxins from the environment they come from ... which is quite a bit different from carrying parasites even though the end result may still result in death ...

Fish eat live food in nature ... why not feed them what is natural?

[jeep]

Without much time at the moment, all I could say is the source of the live foods is the main concern. If you grow your own daphnia in an un-controlled environment, chances are they may become infested with parasites. Mosquito's can carry tapeworm larvae. Mosquitos, and other critters will soon find your unprotected daphnia environment a suitable home. If you grow them in a controlled environment, your chances of having a great and pure culture would be good...

[raglanroad]

In the 70's, I fed tubifex to oscars. They grew an amazing number in the gravel, all waving from the gravel. Thousands. Poor tank hygeine, I suppose, allowed the wonderful growth of the worms. I agree, starting with a clean culture, and controlled environment, should logically provide a great source of food. Clean tubifex has been a market item to sell to Japan,in the past. Don't know who provides that now.

[JeffreyRichard]

No other comments or thoughts???

[shaunn]

I use blackworms (dan's)... but I am a hobbyist and not in the business. If I had a lot to lose, I wouldn't risk it.

[ShinShin]

Various pathogens require a vector to fulfull their life cycle. Many copepods and worms serve as intermediate hosts. While tubefex can come from polluted waters, toxins are ingested and absorbed into the cells of the worm. Tubifex can and do, however, abound in pristine waters. Trout hatchery run off waters can be full of tubifex. They eat the waste from the hatchery and also any pathogens found in the waste. They are also "vectors" of such pathogens. So are blackworms, bloodworms,cyclops, and daphnia.

There are many basic parasitolgy books describing in detail the life cycles of these pathogens, and their hosts and intermediate hosts.

I would not recommend collecting live foods to feed discus from local streams, ponds, or lakes, no matter how pristine you may think the water is. Raising them in the backyard is probabally less likely to cause problems, but the possibility does exist.

There are places available selling laboratory grade cultures that are guaranteed parasite free.