There seems to be a lot of confusion with regards to bloat, and how it can effect beani, haits etc. I've seen this topic has come up a number of times recently so I decided to re-post this as its own topic.
Hopefully the info below will help clarify some of the common misconceptions surrounding this condition.
Protein in & of itself does not cause bloat. Most excess amino acids are excreted - even by fish classified as strict herbivores, and while excessive amounts of protein can put extra stress on a fishes liver, as those excess amino acids have to be deaminated by the liver before they are excreted, this process does not cause bloat. Excessive amounts of protein can also lead to fat accumulation in the liver, and over time can cause serious health issues, even death in extreme cases - but again, this does not cause "bloat".
Most authorities on this subject now agree that it's intestinal flagellates that typically cause "bloat" conditions in fish, and most certainly not excess protein.
I think that it's important to understand that "bloat" is a
symptom of a disease, not a disease on its own. Intestinal flagellates are common in most freshwater species, and typically these intestinal parasites will not have any serious affect on their host. But, place that same fish under enough stress, enough to weaken its immune system, and within the blink of an eye those same parasites can multiply to numbers that the fish simply can't cope with. If/when those numbers reach epidemic proportions, they can & often will cause damage to the intestinal tract of a fish, and in severe/advanced cases their organs, eventually creating what is commonly referred to as "bloat".
Having said that, excessive overfeeding of any food can on its own cause blockage, and constipation, and the end result is also a "bloat" like condition.
IMO the vast majority of bloat cases have little or nothing to do with the diet, especially in juvenile fish. One does NOT want to limit amino acid (protein) intake with a fry/juvenile. To do so will simply limit growth & overall health in the fish. But that doesn't mean that you feed your fish until it's abdomen is extended like a balloon!
I have raised some of the most bloat prone species of fish on the planet (Tropheus sp., Tropheops macrophthalmus, etc) on diets of 50+% protein, 10% fat (small juvies), and never lost a fish to bloat. There are many other stress factors that can take place in a glass tank, and it is typically those stress factors that trigger an outbreak of internal pathogens, usually Spironucleus vortens, that ultimately result in bloat conditions.
Hexamita Intestinalis is another catch all term to describe the various protozoa that trigger bloat conditions in tropical fish. In the vast majority of cases, those where clinical studies have identified the actual flagellates involved (specifically in cichlids), it has been Spironucleus vortens, not Hexamita or Octomitus species as previously believed. While it appears that much of the earlier identifications in ornamental species of fish may be erroneous, the overall treatment is pretty much identical. Some detailed reading on the subject of treating these flagellates in a very safe, cheap, & effective manner can be found in the link below.
http://www.monsterfishkeepers.com/f...879-Treating-quot-Bloat-quot-aka-Spironucleus
IMO the vast majority of bloat cases with cichlids has nothing to do with the diet, but with other stressful factors, such as aggression from tankmates, lack of shelter, water quality such as dissolved organic compound levels, 02 levels, etc-etc., which in turn can cause a 'normal' amount of intestinal pathogens to proliferate to harmful numbers. In some cases it may be nothing more than survival of the fittest, which is what takes place in wild every day. A fish with a weak immune system will obviously be the first fish to succumb to illness if/when stress becomes a factor, no matter what you feed them.
If/when bloat is caused by diet, it's often the result of fish being overfed by MASSIVE amounts, and/or using a food that contains a large inclusion rate of terrestrial based grains & grain byproducts. In the case of the latter, high grain content is known to cause intestinal blockage due to its poor digestibility, which in turn results in "bloat". The whole protein thing is nothing more than a myth that has been perpetuated in this hobby by those that don't have a clear understanding of how a fish assimilates protein. The only time that I limit protein intake is when the fish begins to gain size. Then I shift them over to more of a maintenance diet, just as one would with a puppy as they begin to mature. Young fry & juvies have high metabolic rates, which require high energy fuel on a constant basis. If you limit that, you will limit growth. Hence feeding a high volume of "greens" to a juvenile fish known to be prone to bloat isn't the answer at all.
When feeding low cost generic foods with excessive grain content, if too much is consumed at once these types of feeds can indeed cause serious gastrointestinal issues in some species, such as those that are prone to bloat. (eg. beani's, hait's, etc)
Also, there is a BIG difference between terrestrial based plant matter (such as soybeans, corn, wheat middlings etc) and plant matter from aquatic sources, such as algae meal, spirulina, and various micro-algae. The former is what many hobbyists have come to refer as "cheap fillers".
A classic example of how/why bloat can take place in a tank of juvenile fish; In an attempt to get massive (monster) gains a hobbyist power feeds their juvenile fish, in doing so bacteria, organic waste, etc builds up quickly in the system, and as fish gain size stress levels in the tank increase from aggression/hierarchy issues. Alos as the fry begin to gain size over a few months sometimes those massive regular water changes begin to slide, and now you have a breeding ground of bacteria, and stress levels that are climbing every day. The perfect scenario for an outbreak of spironucleus aka bloat.
The direct cause of the bloat wasn't the food, it was a case of operator error. Feeding fish is part art, and part science, feed a high quality easily digestible food, throw as much clean water at your fish as humanly possible, and keep them in an overall stress free environment and bloat will usually become a non issue.
IMO almost all ailments in fish are triggered by
stress, and one needs to learn early on what each set ups limitations are. If/when we attempt to go beyond those limitations, we risk the health of everything within our system. Some hobbyists seem to learn this straight away, others never seem to catch on & when things go south they look for something to blame, instead of taking responsibility for their own actions. Human nature I guess. Most experienced beani keepers will recommend that this species does best on its own, just as many other cichlid species that are bloat magnets. Generally speaking these species do not do well (long term) in community settings as there is always a struggle for hierarchy within the tank. This constant struggle for dominance causes stress, and often this stress eventually triggers bloat in species that are more sensitive to this condition.
Sometimes when these ailments surface it seems to appear that there is no reason at all. IMO the reason for this is due to the fact that all fish are individuals, and while they can have individual behaviors & temperaments, I also believe that each fish can only tolerate individual levels of stress before they weaken enough to become susceptible to these stressors. You'll typically find that the same holds true for most organisms on our planet, including humans.
Just as one can have genetic runts, I also believe that one can end up with fish that have genetically weak immune systems, or at least weaker than normal. This would explain why one fish in a tank full of (any species), can end up with fungus, or pop eye, or HITH, or whatever, while other fish in the same tank have no health issues whatsoever. Or why some fish survive an ammonia spike, while others drop like flies. Or why only one female in a tank full of breeders ends up egg bound, while no other females ever exhibit this problem. IMO the same applies to bloat.
In the wild Mother Nature has a way of dealing with fish such as this, but what if some of these fish are collected, and exported? How many people cull WC fish? Most breeders will do almost anything to save a prized egg bound female, yet in the wild that fish would either pull through on its own, or else .....
Overuse of medication can also cause an immune system to become severely compromised. Many exporters & importers dose the fish with meds shortly after they are collected or received, again with tranqs when the fish are shipped, while many hobbyists dose the fish yet again with meds when they arrive to their new home. (as a precautionary step) Already the fish have the odds stacked against them, and all it takes is one single weak link to start a snowball effect in ones tank.
Perhaps in some cases, even when we do everything right, it ultimately all boils down to nothing more than a roll of the dice with certain individual fish. The bottom line is, quality protein is not the enemy.
My apologies for being long winded in this post, but this is a topic that seems to repeat iteself on a weekly basis on this forum & many others, especially the connection between bloat & protein. There is absolutely no credible evidence to suggest that protein causes bloat in any species of fish, unless that protein is from low quality sources that are difficult for certain fish to digest. The notion that protein is to blame goes back 25+ years ago when most commercial foods did in fact contain vast amounts of terrestrial based grains, which did in fact cause gastrointestinal issues (especially when overfed) in some species of fish. Unfortunately this outdated misconception still lingers in the hobby today.
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I posted the following in another discussion today, and might as well add it here as well.
While I have posted the following link a number of times, I'm guessing most people haven't taken the time to read this entire paper. It's a long read (200+ pages) but well worth the time for anyone that wants to really understand what the root cause is for most cases of "bloat" in cichlids.
I've taken the time to compile some key portions of this paper which should help explain how bloat comes about, exactly what causes it in ornamental warm water tropical species of fish, and how young fish are more susceptible to severe cases of bloat vs larger fish.
http://scholar.lib.vt.edu/theses/available/etd-120399-140825/unrestricted/ANGEL.PDF
From this paper we know that these parasitic protozoa can be found in the intestinal tracts of healthy fish. We also know that STRESS, which weakens a fishes immune system, allows these flagellates to multiply in numbers to the point of causing systemic infections, which left unchecked will typically result in the death of the fish.
We also know that smaller fish are more susceptible to these flagellates compared to larger fish (such as juvie beanis), NOT because of an undeveloped stomach as previously suggested in another thread, but due to an undeveloped immune system. Just like in humans, juveniles and elderly specimens are typically at far greater risk from disease, bacteria, etc, than a healthy specimen in their prime with a fully developed & well functioning immune system.
This is precisely why many people have difficulty with young immature bloat prone species, compared to when these species reach semi-adult stages.
This paper supplies the most in-depth research that I think one can currently find on this subject, and is well worth the read for anyone that wants to better understand "bloat", beyond what you will typically read on the various fish forum chat rooms.
HTH
