Oscar77
27-04-2006, 06:49 PM
Below just some parts abstract from an article, please refer to the full article for further reading. Here is the link : http://www.cichlid-forum.com/articles/spironucleus.php#i.%20%20Foreword
1. Introduction
The majority of us will have heard of, or in many cases, have had fish that have suffered from the following symptoms:
A darkening in colours
A tendency to 'hang' in corners, or to remain in isolation from other fish,even at feeding
A tendency to stare at food but without eating it, or if it does take a
sample it immediately spits it out again
The decline in food acceptance, is often accompanied or followed by lethargy, and a reduction in muscle tissue which gives the fish a 'pinched'
appearance behind the head and the skin 'texture' may take on a roughened appearance
White, jelly like excreta can often be seen trailing from the anal vent, on the floor of bare bottom aquaria, or sometimes white, stingy 'rotted plant-like material' is 'adrift' in the aquarium
The wasted fish may develop a bloated stomach region
Skin lesions may start to appear, especially on the body and the head, in the region of the lateralis system - these holes may eventually expand and connect to from considerable size 'craters'
Over the years there have been many names attributed with the above symptoms. Some of these include:
• Hole in the head disease - HITH
• Head and Lateral Line Erosion - HLLE
• Hex
• Flagellate Infestation
• Holes disease
• Hexamitiasis
• Wasting Disease
• Spironucleus
• Malawi Bloat
• Dropsy
The list is almost as endless at the range of causative phenomena and cures that have been attributed to the above symptoms. My aim in writing this paper is to introduce to the discus hobbyists some of the recent developments that have been made in the identification of the causative organism, for what I will refer to, from here on in, as 'Spironucleus'; and also to consider some of the methods and implications for treating a Spironucleus infestation in Discus Symphysodon species.
In discus, the prime organism responsible for much of the woe described above has been identified as Spironucleus vortens (an organism that also affects other cichlids e.g. Angels, Pterophyllum scalare, P. Altum etc (Paull and Matthews, 2001). S. vortens has an elongated body that is approximately 8 to 14 µm long & 3 to 6 µm wide. It has 6 anterior and 2 posterior flagella and possesses 2 sigmoid shaped, elongated nuclei.
2. Where are flagellates found in discus
Paull and Matthews (2001) were able to isolate S. vortens from the intestine, kidney, liver, spleen, and head lesions of discus; and also from the intestine and head lesions of angelfish. In addition, studies by Somboon (2002) found S. vortens in the blood, stomach, intestine, spleen, gall bladder, and ovaries of angel fish. Somboon also found S. vortens in apparently healthy fish.
Paull and Matthews (2001) note that S. vortens interacts with the gut wall of the discus, attaching itself to the intestinal mucosa. In addition, they suggest that there may well be some form of intracellular interaction within epithelial cells lining the intestine. If the flagellates reach epizootic proportions they suggest that it is via the invasion of the lamina propria (loose connective tissue/mucosa) that systemic entry, and infection of additional organs, especially the liver, may be achieved. Paull and Matthews (2001; and many others) suggest that it is at this point of dissemination that an infestation S. vortens becomes lethal.
In simple terms, in 'healthy discus' S. vortens is commonly found in the flagellated stage in the lumen of the upper intestine, where it remains, controlled by the immune system of the fish. In stressed discus, the immune system is placed under greater strain, and the organism, in theory, multiplies unchecked causing considerable localised damage. Once the damage is severe enough the intestinal lining is penetrated and the S. vortens enters the blood causing systemic and organ infections. In regards to stress, I have stated elsewhere (Stewart, 2001) that stressors can include: low oxygen levels, high nitrite levels, comparatively high (or low) water temperatures, rough handling, mechanical injury, overcrowding, water of inappropriate hardness etc (see Francis-Floyd, 1997; Rottmann, Francis-Floyd, Durborow, 1992 for more information on stress and its effects and management).
3. 'Holes', organ/systemic infection and jelly excreta
As mentioned above, Paull & Matthews (2002) found S. vortens, to some degree, in all of the fish that they studied - including the controls. In addition, S. vortens were isolated from the lateralis lesions of the fish studied, which supports Bassleer's 1983 work. It was suggested that the flagellates either caused the holes through 'direct infection' (least likely); or that, the 'host tissue underneath the skin or indirectly by blocking the tiny blood vessels that supply the sensory system' (most likely). If one, takes into consideration the nutrient deficiencies that are said to occur during severe and systemic infections it is no wonder that the lateralis system begins to disintegrate. Of the cases studied by Paull and Matthews (2001) where the external manifestations of S. vortens were severe, S. vortens had always progressed to the liver, spleen and kidney. In the less severe cases the parasite had yet to progress to the aforementioned organs and 'in these instances the infection appeared to be in a state of remission'.
In regards to the 'jelly' excreta found in aquaria, one often reads comments such as 'it is only the stomach lining of the fish - and is perfectly harmless'. This needs addressing. The stomach lining or for that matter, the whole of the epithelial cells of the digestive tract undergo constant replacement, day in day out. For sufficient to be shed to be fully visible and of considerable dimensions, either the fish has been turned inside out, or there is a problem. At this point it should be noted that feeding meat-mixes based on gelatine can result in the discus passing 'a sheet of membrane like whitish material' and this should not be confused with what is being discussed. Importantly, in discus the final protein uptake occurs in the intestine, not the stomach. It is in the intestine that the 'protein digesters' of: trypsin, chymotrypsin and metalloproteases are found (Chong et al., 2002). Their location and the findings by Paull & Matthews (2001) is indicative that if, and this is a big if, the sheet of whitish material being passed is 'lining', it is intestinal lining ,and may well be the product of protein digesters, and flagellate damage to the lumen and mucosa. In addition, their evidence helps explain why 'hole closure' occurs post nutritional supplementation.
4. The transmission of Spironucleus
Whilst there is little known at the moment on the complete lifecycle and transmission of Spironucleus vortens it is reasonable to expect that it is very similar to other Spironucleus species. One way that Spironucleus may be transmitted is via contaminated faecal material. That is the adult trophozoite undergoes longitudinal binary fission in the intestine, the trophozoites are then passed in faeces. It may also be possible that cysts are produced and evacuated in a similar manner, though this is yet to be demonstrated; however other diplomonads have reproduced in this manner under laboratory conditions (Poynton, Sterud, 2002). In this way, discus 'pecking' at the base of the aquarium are likely to ingest S. vortens. Post ingestion excystment would occur, if cysts are involved; and/or the newly ingested trophozoites would start to colonise the mucosal surface and mucus layer of the small intestinal lumen - and so the cycle continues.
5. Treatments
Today the most common treatments propounded are 'vitamins and minerals - that is all you need this will cure everything’, 'heat treatment - crank the temps and kill all bugs', 'metronidazole the fish - chuck it in the tank and in 3 days your fish will be breeding babies by the millions and be laughing and smiling', or 'it's a wire, it's a wire, your fish has eaten halfway through the heater cable and is being blasted by stray voltage', and finally I suspect that there are those that think S. vortens is in fact a killer bug devised by some discus super power (which happens to be the only person with a cure) and is simply one step in global discus domination.
Therefore I will try to treat this section fairly and rationally in the hope that people will see that 1 factor in isolation - does not a cure make and that the problem often needs a more holistic approach.
5.1 Metronidazole
When one recommends the use of metronidazole in the treatment of fish on many of the 'popular' forums - there is often a cry of 'be warned it is mutagenic and carcinogenic and your fish will die a thousands deaths'. Whilst I am firm believer in 'warnings' on the overuse of drugs, I do feel that at times their expedient use may well be appropriate and safe.
In respect to the mutagenic and carcinogenic warnings, often those postings refer to information extracted from 'clinical statistical results' and quote the results as statistical certainties for 'normal' dosing levels of the drug involved. The trouble with this is if you look in a Physician's Desk Reference (PDR), what tends to catch the eye is the glaring warnings on 'chronic, high dose', and it often takes 20 minutes or more of detailed reading to realise that what is in fact being referred to is a dose that is taken orally at 5X the recommended dose, for 30 days or you IV the drug for 3 days at 3X the recommended dose. It is this information that is the foundation of the 'statistical' results on mutagenic activity, and often takes the form of an 'assay' - i.e. not in a mammal, (in chemicals, as opposed to live animals).
Taking the above into account, current 'recommended' dosage, and the half life of metronidazole I consider the risk that our discus are going to develop three heads or become riddled with cancer a week later, reasonably minimal.
Dosage
Please refer to the link by clicking - DOSAGE (http://www.cichlid-forum.com/articles/spironucleus.php#4.1.2.1***%20%20Dosage%20in%20wat er)
Come across one of the method in treating hole in the head (HITH). Pics taken from : http://bbs.cnfish.com/dispbbs.asp?b...D=121283&page=1. Personally I find it amazing, therefore, posted here to share with others.
After checking with the Thread Starter (Mod of that site), for normal case, it need 1 routine in order to cure. For serious case, might need 2-3 routine. Fish will show sign of recovery after 3 days.
Hope you find this beneficial to you.
Pic # 1 - The fish with HITH
Pic # 2 - Medicine - Metronidazole
Pic # 3 - Cotton Bud
Pic # 4 - Make the Metronidazole into powder form
Pic # 5 - Cleaning the hole in the head with cotton bud
Pic # 6 - Cleaning the hole in the head with cotton bud
Pic # 7 - Cleaning the hole in the head with cotton bud
Pic # 8 - Apply the Metronidazole powder on the hold in the head
Pic # 9 - Fish recover from HITH
1. Introduction
The majority of us will have heard of, or in many cases, have had fish that have suffered from the following symptoms:
A darkening in colours
A tendency to 'hang' in corners, or to remain in isolation from other fish,even at feeding
A tendency to stare at food but without eating it, or if it does take a
sample it immediately spits it out again
The decline in food acceptance, is often accompanied or followed by lethargy, and a reduction in muscle tissue which gives the fish a 'pinched'
appearance behind the head and the skin 'texture' may take on a roughened appearance
White, jelly like excreta can often be seen trailing from the anal vent, on the floor of bare bottom aquaria, or sometimes white, stingy 'rotted plant-like material' is 'adrift' in the aquarium
The wasted fish may develop a bloated stomach region
Skin lesions may start to appear, especially on the body and the head, in the region of the lateralis system - these holes may eventually expand and connect to from considerable size 'craters'
Over the years there have been many names attributed with the above symptoms. Some of these include:
• Hole in the head disease - HITH
• Head and Lateral Line Erosion - HLLE
• Hex
• Flagellate Infestation
• Holes disease
• Hexamitiasis
• Wasting Disease
• Spironucleus
• Malawi Bloat
• Dropsy
The list is almost as endless at the range of causative phenomena and cures that have been attributed to the above symptoms. My aim in writing this paper is to introduce to the discus hobbyists some of the recent developments that have been made in the identification of the causative organism, for what I will refer to, from here on in, as 'Spironucleus'; and also to consider some of the methods and implications for treating a Spironucleus infestation in Discus Symphysodon species.
In discus, the prime organism responsible for much of the woe described above has been identified as Spironucleus vortens (an organism that also affects other cichlids e.g. Angels, Pterophyllum scalare, P. Altum etc (Paull and Matthews, 2001). S. vortens has an elongated body that is approximately 8 to 14 µm long & 3 to 6 µm wide. It has 6 anterior and 2 posterior flagella and possesses 2 sigmoid shaped, elongated nuclei.
2. Where are flagellates found in discus
Paull and Matthews (2001) were able to isolate S. vortens from the intestine, kidney, liver, spleen, and head lesions of discus; and also from the intestine and head lesions of angelfish. In addition, studies by Somboon (2002) found S. vortens in the blood, stomach, intestine, spleen, gall bladder, and ovaries of angel fish. Somboon also found S. vortens in apparently healthy fish.
Paull and Matthews (2001) note that S. vortens interacts with the gut wall of the discus, attaching itself to the intestinal mucosa. In addition, they suggest that there may well be some form of intracellular interaction within epithelial cells lining the intestine. If the flagellates reach epizootic proportions they suggest that it is via the invasion of the lamina propria (loose connective tissue/mucosa) that systemic entry, and infection of additional organs, especially the liver, may be achieved. Paull and Matthews (2001; and many others) suggest that it is at this point of dissemination that an infestation S. vortens becomes lethal.
In simple terms, in 'healthy discus' S. vortens is commonly found in the flagellated stage in the lumen of the upper intestine, where it remains, controlled by the immune system of the fish. In stressed discus, the immune system is placed under greater strain, and the organism, in theory, multiplies unchecked causing considerable localised damage. Once the damage is severe enough the intestinal lining is penetrated and the S. vortens enters the blood causing systemic and organ infections. In regards to stress, I have stated elsewhere (Stewart, 2001) that stressors can include: low oxygen levels, high nitrite levels, comparatively high (or low) water temperatures, rough handling, mechanical injury, overcrowding, water of inappropriate hardness etc (see Francis-Floyd, 1997; Rottmann, Francis-Floyd, Durborow, 1992 for more information on stress and its effects and management).
3. 'Holes', organ/systemic infection and jelly excreta
As mentioned above, Paull & Matthews (2002) found S. vortens, to some degree, in all of the fish that they studied - including the controls. In addition, S. vortens were isolated from the lateralis lesions of the fish studied, which supports Bassleer's 1983 work. It was suggested that the flagellates either caused the holes through 'direct infection' (least likely); or that, the 'host tissue underneath the skin or indirectly by blocking the tiny blood vessels that supply the sensory system' (most likely). If one, takes into consideration the nutrient deficiencies that are said to occur during severe and systemic infections it is no wonder that the lateralis system begins to disintegrate. Of the cases studied by Paull and Matthews (2001) where the external manifestations of S. vortens were severe, S. vortens had always progressed to the liver, spleen and kidney. In the less severe cases the parasite had yet to progress to the aforementioned organs and 'in these instances the infection appeared to be in a state of remission'.
In regards to the 'jelly' excreta found in aquaria, one often reads comments such as 'it is only the stomach lining of the fish - and is perfectly harmless'. This needs addressing. The stomach lining or for that matter, the whole of the epithelial cells of the digestive tract undergo constant replacement, day in day out. For sufficient to be shed to be fully visible and of considerable dimensions, either the fish has been turned inside out, or there is a problem. At this point it should be noted that feeding meat-mixes based on gelatine can result in the discus passing 'a sheet of membrane like whitish material' and this should not be confused with what is being discussed. Importantly, in discus the final protein uptake occurs in the intestine, not the stomach. It is in the intestine that the 'protein digesters' of: trypsin, chymotrypsin and metalloproteases are found (Chong et al., 2002). Their location and the findings by Paull & Matthews (2001) is indicative that if, and this is a big if, the sheet of whitish material being passed is 'lining', it is intestinal lining ,and may well be the product of protein digesters, and flagellate damage to the lumen and mucosa. In addition, their evidence helps explain why 'hole closure' occurs post nutritional supplementation.
4. The transmission of Spironucleus
Whilst there is little known at the moment on the complete lifecycle and transmission of Spironucleus vortens it is reasonable to expect that it is very similar to other Spironucleus species. One way that Spironucleus may be transmitted is via contaminated faecal material. That is the adult trophozoite undergoes longitudinal binary fission in the intestine, the trophozoites are then passed in faeces. It may also be possible that cysts are produced and evacuated in a similar manner, though this is yet to be demonstrated; however other diplomonads have reproduced in this manner under laboratory conditions (Poynton, Sterud, 2002). In this way, discus 'pecking' at the base of the aquarium are likely to ingest S. vortens. Post ingestion excystment would occur, if cysts are involved; and/or the newly ingested trophozoites would start to colonise the mucosal surface and mucus layer of the small intestinal lumen - and so the cycle continues.
5. Treatments
Today the most common treatments propounded are 'vitamins and minerals - that is all you need this will cure everything’, 'heat treatment - crank the temps and kill all bugs', 'metronidazole the fish - chuck it in the tank and in 3 days your fish will be breeding babies by the millions and be laughing and smiling', or 'it's a wire, it's a wire, your fish has eaten halfway through the heater cable and is being blasted by stray voltage', and finally I suspect that there are those that think S. vortens is in fact a killer bug devised by some discus super power (which happens to be the only person with a cure) and is simply one step in global discus domination.
Therefore I will try to treat this section fairly and rationally in the hope that people will see that 1 factor in isolation - does not a cure make and that the problem often needs a more holistic approach.
5.1 Metronidazole
When one recommends the use of metronidazole in the treatment of fish on many of the 'popular' forums - there is often a cry of 'be warned it is mutagenic and carcinogenic and your fish will die a thousands deaths'. Whilst I am firm believer in 'warnings' on the overuse of drugs, I do feel that at times their expedient use may well be appropriate and safe.
In respect to the mutagenic and carcinogenic warnings, often those postings refer to information extracted from 'clinical statistical results' and quote the results as statistical certainties for 'normal' dosing levels of the drug involved. The trouble with this is if you look in a Physician's Desk Reference (PDR), what tends to catch the eye is the glaring warnings on 'chronic, high dose', and it often takes 20 minutes or more of detailed reading to realise that what is in fact being referred to is a dose that is taken orally at 5X the recommended dose, for 30 days or you IV the drug for 3 days at 3X the recommended dose. It is this information that is the foundation of the 'statistical' results on mutagenic activity, and often takes the form of an 'assay' - i.e. not in a mammal, (in chemicals, as opposed to live animals).
Taking the above into account, current 'recommended' dosage, and the half life of metronidazole I consider the risk that our discus are going to develop three heads or become riddled with cancer a week later, reasonably minimal.
Dosage
Please refer to the link by clicking - DOSAGE (http://www.cichlid-forum.com/articles/spironucleus.php#4.1.2.1***%20%20Dosage%20in%20wat er)
Come across one of the method in treating hole in the head (HITH). Pics taken from : http://bbs.cnfish.com/dispbbs.asp?b...D=121283&page=1. Personally I find it amazing, therefore, posted here to share with others.
After checking with the Thread Starter (Mod of that site), for normal case, it need 1 routine in order to cure. For serious case, might need 2-3 routine. Fish will show sign of recovery after 3 days.
Hope you find this beneficial to you.
Pic # 1 - The fish with HITH
Pic # 2 - Medicine - Metronidazole
Pic # 3 - Cotton Bud
Pic # 4 - Make the Metronidazole into powder form
Pic # 5 - Cleaning the hole in the head with cotton bud
Pic # 6 - Cleaning the hole in the head with cotton bud
Pic # 7 - Cleaning the hole in the head with cotton bud
Pic # 8 - Apply the Metronidazole powder on the hold in the head
Pic # 9 - Fish recover from HITH