In the disease part of the forum – it comes a lot of advises according handling stringy white poops that often show up when you buy a new fish. The general answer to this is that the fish have internal parasites – treat ASP and it is often recommended to treat with Metronidazole or its derivates. IMO – this is one of the more dangerous myths existing in the reefing community and in this short write up – I try to show why I have this standpoint
In every serious guideline according long-time transports of fishes there is a demand of starvation 1 to 3 days before transport. This because of lowering the stress respond during transport, the metabolism and hence the secretion of NH3/NH4. This means that many fishes (those with short bowel length – often omnivores and carnivores) will arrive with empty digestive tract and when they start to eat – they will have a threadlike thin stringy white poop. This is natural and IMO a sign that the transport has been handled in the right way.
How in heck have this been converted to a holy rule that SW fishes with this stringy white poop have internal parasites and need to be treated with Metronidazole or its derivates? I do not know for sure, but I have a clue of the reason why this dangerous and false rumour have arisen.
In the world of freshwater cichlids there is a very feared disease known in the English-speaking world as African bloat. The disease start with that the fish will be shy, try to eat but spit it out, stop eating, show a stringy white pop and if not the fish will be treated, the belly will swell and the fish die.
Back around 1977 this disease was very common among especially fishes from the Tropheus genera (a Lake Tanganyika cichlid) and fishes normal named Tanganyika clowns (fishes from the genera of Eretmodes, Tanganicodus and Spathodus). In Sweden – these fishes were very popular at that time many attempts were done in order to defeat the disease. Of some reason I was stuck with some information that the agent could be a flagellate of the Hexamita genera. Hexamita was at that time seen as the causative agent for Hole in Head disease among Discus. There was a compound available in the Swedish market that say it was effective against Hole in Head. I tried that with success and I tell a friend of mine that this could be a flagellate caused disease. He was working in a Medical company and have access to pure Metronidazole and directly tell me to test that – but they are not eating I said but because of the lipophilic nature of the drug – he thought that the fish would take it up from the water. I test and it work all the way down to the white stringy pop stage. Because it was impossible to recommend the pure drug – me and a friend did test commercial drugs with Metronidazole or its derivates (flagyl and emtrylevet)
I published an article in a Swedish Cichlid bulletin late 1977 and the problem was solved. Around 1982 – there was some disease outbreak that clearly show that probably a resistant strain of the agent had arisen in Germany or Sweden. It was impossible to treat with the normal medicines. Now another approach was taken – peoples start to work with the food and water quality much more and today it is not a common disease, but the agent is probably in every FW aquarium.
However, for long time the common advice if you had a cichlid of the sensitive species that not eat and have stringy white pop – treat with metronidazole or its derivates. Somehow – it looks like the first criteria (not eat) from this advises have gone away when it was transferred into the reefing community – because that´s exactly what I think this common advises with white stringy pop is – a translation from the fresh water world and the cure is the same metronidazole or its derivates.
I do not really know if these flagellates even exist in SW
OK but it is only what a crazy Swede suspect and in order to be sure (he has been proven wrong before) I treat with metronidazole just in case off.
Fair enough but I want to highlight a few characteristics that metronidazole has.
It is lipophilic – it means it will be taken up from the water by SW fish through diffusion (and bioaccumulate) through mostly the gills and be oral taken by the fact that SW fish drink. It will bioaccumulate in other living organisms too
It is a anti flagellate drug – but for me it is unknown if it affects all types of flagellates (have in mind that the zoox is a type of flagellates)
It have antibacterial activity. Around 1962 metronidazole was discovered by accident to have antibacterial activity – especially against gram-negative anaerobes – with other words many gut bacteria.
It is often used against anaerobic infection after bowel surgery when it is a risk that anaerobic bacteria from digestive track have come out in the stomach cavity.
You get a fish that have starved for a period, hungry and eating but show white pop because of starvation – the first the kind aquarist do is to destroy the whole bacteria community of the digestive tract in fear of a disease that no one knows if it exists at all in saltwater fish. Talk about kindness to death
If a SW fish show up all four indications of African bloat – shy, dark coloured, not eating or even interest of food and showing up a thin, stringy white pop – I would be considering to do a treatment with help of metronidazole – especially if the fish have been normal before. But knowing the effects of metronidazole on gut bacteria. I´ll be very, very carefully to use this drug. Even in low concentrations in the water because of uptake in the fish body.
IMO it is very seldom there is real internal parasite infections in our SW fish even if some state an infection rate of nearly 100 %. White poops is many times used as prove. When I suspect internal parasites is when the fish eat a lot, not gain weight and the part between the eyes and dorsal fin looks like a razor blade.
Sincerely Lasse
In every serious guideline according long-time transports of fishes there is a demand of starvation 1 to 3 days before transport. This because of lowering the stress respond during transport, the metabolism and hence the secretion of NH3/NH4. This means that many fishes (those with short bowel length – often omnivores and carnivores) will arrive with empty digestive tract and when they start to eat – they will have a threadlike thin stringy white poop. This is natural and IMO a sign that the transport has been handled in the right way.
How in heck have this been converted to a holy rule that SW fishes with this stringy white poop have internal parasites and need to be treated with Metronidazole or its derivates? I do not know for sure, but I have a clue of the reason why this dangerous and false rumour have arisen.
In the world of freshwater cichlids there is a very feared disease known in the English-speaking world as African bloat. The disease start with that the fish will be shy, try to eat but spit it out, stop eating, show a stringy white pop and if not the fish will be treated, the belly will swell and the fish die.
Back around 1977 this disease was very common among especially fishes from the Tropheus genera (a Lake Tanganyika cichlid) and fishes normal named Tanganyika clowns (fishes from the genera of Eretmodes, Tanganicodus and Spathodus). In Sweden – these fishes were very popular at that time many attempts were done in order to defeat the disease. Of some reason I was stuck with some information that the agent could be a flagellate of the Hexamita genera. Hexamita was at that time seen as the causative agent for Hole in Head disease among Discus. There was a compound available in the Swedish market that say it was effective against Hole in Head. I tried that with success and I tell a friend of mine that this could be a flagellate caused disease. He was working in a Medical company and have access to pure Metronidazole and directly tell me to test that – but they are not eating I said but because of the lipophilic nature of the drug – he thought that the fish would take it up from the water. I test and it work all the way down to the white stringy pop stage. Because it was impossible to recommend the pure drug – me and a friend did test commercial drugs with Metronidazole or its derivates (flagyl and emtrylevet)
I published an article in a Swedish Cichlid bulletin late 1977 and the problem was solved. Around 1982 – there was some disease outbreak that clearly show that probably a resistant strain of the agent had arisen in Germany or Sweden. It was impossible to treat with the normal medicines. Now another approach was taken – peoples start to work with the food and water quality much more and today it is not a common disease, but the agent is probably in every FW aquarium.
However, for long time the common advice if you had a cichlid of the sensitive species that not eat and have stringy white pop – treat with metronidazole or its derivates. Somehow – it looks like the first criteria (not eat) from this advises have gone away when it was transferred into the reefing community – because that´s exactly what I think this common advises with white stringy pop is – a translation from the fresh water world and the cure is the same metronidazole or its derivates.
I do not really know if these flagellates even exist in SW
OK but it is only what a crazy Swede suspect and in order to be sure (he has been proven wrong before) I treat with metronidazole just in case off.
Fair enough but I want to highlight a few characteristics that metronidazole has.
It is lipophilic – it means it will be taken up from the water by SW fish through diffusion (and bioaccumulate) through mostly the gills and be oral taken by the fact that SW fish drink. It will bioaccumulate in other living organisms too
It is a anti flagellate drug – but for me it is unknown if it affects all types of flagellates (have in mind that the zoox is a type of flagellates)
It have antibacterial activity. Around 1962 metronidazole was discovered by accident to have antibacterial activity – especially against gram-negative anaerobes – with other words many gut bacteria.
It is often used against anaerobic infection after bowel surgery when it is a risk that anaerobic bacteria from digestive track have come out in the stomach cavity.
You get a fish that have starved for a period, hungry and eating but show white pop because of starvation – the first the kind aquarist do is to destroy the whole bacteria community of the digestive tract in fear of a disease that no one knows if it exists at all in saltwater fish. Talk about kindness to death
If a SW fish show up all four indications of African bloat – shy, dark coloured, not eating or even interest of food and showing up a thin, stringy white pop – I would be considering to do a treatment with help of metronidazole – especially if the fish have been normal before. But knowing the effects of metronidazole on gut bacteria. I´ll be very, very carefully to use this drug. Even in low concentrations in the water because of uptake in the fish body.
IMO it is very seldom there is real internal parasite infections in our SW fish even if some state an infection rate of nearly 100 %. White poops is many times used as prove. When I suspect internal parasites is when the fish eat a lot, not gain weight and the part between the eyes and dorsal fin looks like a razor blade.
Sincerely Lasse
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