Cichlid diet

[Lawlboom]

I was listening to a petliferadio podcast at work and they had a guest on Don Conkel who was one of the first people involved in central american cichlids. Anyway he mentioned that in his facilities they mix cichlid staple foods which are high in protein with koi food which is high in fiber. Mentioned that when they observed the contents of the fishes stomachs in the wild, well over half was detritus.

I feel like in all of my reading I have never seen the fiber necessity pop up. Maybe I missed it, but what are your thoughts on this? Mr. Conkel alluded that ensuring they get fiber was vital to the long term health of the fish.

 

[RD.]

The vast majority of commercial operations, including Don's, cannot afford to feed what most hobbyists feed their fish, so they compromise. His logic for feeding koi food is old school, and certainly not based on science. Fish don't need to crap excessively to keep their gut in check.


With regards to fiber .....

All plant ingredients contain a certain amount of fiber in the form of cellulose, hemicellulose, lignin along with other complex carbohydrates, that are generally indigestible to fish. Fiber adds physical bulk to the feeds, and a certain amount of fiber in food permits better binding and possibly with some diets helps move food through the alimentary canal. It has been noted (De Silva and Anderson (1995) that it was not desirable to have a fiber content above 8-12% in diets designed for any species of fish, as the increase in fiber content would consequently result in the decrease of the quality of an unusable nutrient in the diet. When fiber content is excessive, it results in lower digestibility of nutrients, and an increase in fecal matter. Therefore fiber content should be limited in order to improve overall digestibility of the food. If food moves too quickly through the digestive tract, nutrients may not be fully absorbed. Most commercial feed formulations designed for tropical species of fish contain 3-5% fiber content.

The following quote is from an article by Frank A. Chapman, associate professor and Extension aquaculture specialist, Program in Fisheries and Aquatic Sciences; and Richard Miles, professor, Department of Animal Sciences, University of Florida.

https://edis.ifas.ufl.edu/fa159


“Typical values for crude protein in fish production feeds normally range from 36% to 42%, for lipid 6% to 15%, and for crude fiber 3% to 5%. Feeds with high protein and lipid content coupled with low fiber are generally considered to be of higher quality than those with a high fiber content. Fish have no specific requirement for fiber, and feeds with high fiber content (higher than 8%) are of low feeding value simply because of the diluting effect of fiber in the diet.”

 

[Lawlboom]

Thanks for very detailed answer! That would probably be why I have not read anything about high fiber foods.

 

[RD.]

There are herbivorous species that can benefit from higher then normal levels of fiber, but IMO that fiber shouldn't come from terrestrial based plant matter, that is typically found in most koi food. Better to come from raw ingredients more suited to finfish, such as the chitin found in krill/shrimp shells, or from aquatic plant matter, such as kelp or algae meal.

 

[Lawlboom]

I've been a bad aquarist and never really spent much time reading about diet. I do supplement my Uaru with frozen "emerald cuisine" or other algae type foods. Aside from that it's just been dump hikari gold and walk away.

The good news is now I have something new to read up on.

 

[Pomatomus]

High protein is more necessary for young fish, as they need it to grow muscle and other tissues. Older fish convert less of the feed consumed to body mass, so in theory I agree with Don when it comes to adult fish, but not juveniles. I have seen his farm and he told me the same thing when I was fresh out of college.

If you need me to ask any of those professors at the University of Florida about this, I can do that for you. I am currently enrolled in their Master's program. I took the Fish Nutrition course last year and 100% agree with everything RD said. That was a great post!

 

[duanes]

I have been to Don's breeding facility in Fl, and have seen his breeders. The colors, health and sizes were magnificent, so I'd have a hard time arguing with his methods. And many of the species he offers are detritivores, and/or primarily vegetable and fruit eaters in nature (Vieja, or the Cincelichthys (newly created pearsei/bocourti genus).
I found feeding those cichlids, and other non-predatory species high vitamin koi foods and leafy greens worked well for me too.


as an aside
I just read an interesting study about the way Parjachromis dovii feed in nature, while as juveniles the main portion of stomach contents found were small fish, as adults a majority of stomach contents were insects.
http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442000000200019

 

[neutrino]

Considering all the possible variables, my primary add to some of the good info above would be there's a big difference between aquatic algae and plants, or some of the leafy veggies some might feed fresh and in small amounts to certain types of fish, or the seeds, fruits, or whatever other vegetable matter that may be found in a fish's natural habitat vs. the commerical corn or soy based ingredients (or some of the other commercial food and beverage production by products) used in some fish foods to prop up protein numbers or for 'fiber', some of these ingredients being ones that science and aquaculture studies have been showing can cause problems in fish, such as intestinal inflammation and immunity issues. (Tolerance of some of these ingredients varies somewhat by species.) Some of these ingredients are problematic in themselves (soy) or especially problematic in combination with other items (soy and peas).

Just a couple of references if you'd like to do some of your own reading on it:
https://www.sciencedaily.com/releases/2008/12/081205095954.htm

https://www.sciencedaily.com/releases/2013/12/131203090706.htm
Articles are primarily focused on salmon production, so just in case this leads someone to believe it doesn't apply to other fish-- from the above article:

The increased use of plant materials results in many cases to less growth and presents a hazard to the digestive health of many fish species, including salmon.

 

[neutrino]

...and to continue with one added thought-- I've often wondered how many times someone who feeds a fish food heavy in soybean meal or similar ingredients and regularly adds peas or something similar as a treat, finds that his fish develop digestive based health issues, and then, without knowing the problems with some of the ingredients, especially in combination, attributes any resulting health issues to something irrelevant for most fish, like floating vs. sinking pellets.

 

[RD.]

IME, the vast majority of koi foods on the market consist of what I would personally consider excessive amounts of terrestrial based plant matter. That corn, soybean, wheat, etc may be acceptable for a fish such as a koi, that has no stomach, and that can typically assimilate various raw ingredients, and carbohydrate levels, that many tropical species of fish cannot. But not acceptable to me, personally, and the fish I keep.

But there is a massive difference in what may or may not work on a commercial farm, or what is going to be most cost effective, on a commercial farm, vs 3 or 4 tanks in the average hobbyists basement.

I had this discussion with Pablo Tepoot, the owner of New Life Spectrum, several years ago when we were talking about what he fed his fish back in the day. Back when he had several millions of gallons worth of ponds, and concrete vats. This is a man who had his own line of food, but couldn't afford to feed it to his own fish! It just wasn't cost effective to feed 10's of thousands of pond fish, primo food. Now that he is producing the food himself, with his own equipment, on site at his farm in FL, that no longer is true. But for many many years he fed bulk farm feed, just like Don.

So a guy like Don, with the size of his operation, isn't going to be feeding NLS, or Northfin, or Omega, or anything close. He's feeding a "high protein" food, most likely designed for trout, mixed with a bulk commercial koi food. That makes perfect business sense, and the fish would also be consuming natural pond algae, insects, larvae, etc, as a supplement.

Waste isn't near the factor in a large vat, or natural pond setting, but is certainly a concern to most hobbyists, and the larger the fiber content, the more solid waste that will be produced. The key in feeding fish beyond just nutrient levels, is digestibility. Higher quality allows one to feed less, which means less waste, less bacteria, and less of a bio load on the entire system.
In large aquaculture facilities the feed conversion ratio is constantly scrutinized, getting it right can mean the difference in hundreds of thousands of dollars spent, or saved, in feed.

I have no issue adding fiber to the diet of species that require additional fiber, I'm just saying that there are better ways to do it than feeding your typical grain loaded koi food.