Tetrahymena ciliates were probably the first unicellular organisms to be observed and identified. Anton Leeuwenhoek accomplished this more than 300 years ago; he was the one who started to deliberately study the microworld around us. Leuwenhoek discovered a whole world in a drop of water with the aid of the finest, most powerful magnifying glasses available at the time he learned to make them. Furthermore, it required tetrahymena to function. However, this isn’t currently what has made them famous. They are well known for their rapid reproduction and killing speed. They are now increasingly frequently discovered on aquarium fish.
 |
| Photo 2. Tetrahymena settled at the base of the caudal fin of this apistogram. They like to delve into muscle tissue along the rays of the fins. The affected area is marked with an arrow. |
For a long time, only one species of tetrahymen was mentioned in the literature on fish diseases – Tetrahymena pyriformis. And not in every book, and then only in passing, since it was believed that tetrahymena themselves are quite harmless and are found exclusively on very weakened, almost dying fish. Tetrahymena were considered more likely to be "scavengers", than parasites. And since they are very easily cultivated, rapidly increasing their numbers, it was often suggested to even feed them to fish fry. However, isn"t this playing with fire? Guppy lovers have already encountered a cruel killer, Tetrahymena corlissi (Tetrahymena corlissi), which causes a severe guppy disease (Guppy Disease). But guppies, and many other aquarium and non-aquarium fish, can also be killed by Tetrahymena pyriformis ( FISH DISEASE. Diagnosis and Treatment, 2010 Edward J.Noga) .
Tetrahymena are one of the favorite objects for scientific research of molecular biologists. They, in particular, study the mechanisms of immortality. As a result of studies of the structure of nucleic acids of tetrahymena and the features of their structure using an electron microscope, it turned out that in addition to the biological species Tetrahymena pyriformis there are several more very similar relatives to it. The term "T" appeared Tetrahymena pyriformis-complex " by which they mean a group that includes at least 14 still very close, but rapidly evolving species.
A graphic depicting the evolutionary relationships between closely related ciliates from other genera and the various Tetrahymena species. A spot for the ichthyophthirius pathogen can also be seen in the upper left corner of the image.
The ability to switch from feeding on bacteria to feeding on the tissues of higher organisms has arisen more than once in various members of this group. It is noteworthy that tetrahymena can parasitize not only on the surface of the fish body. They penetrate the muscles, abdominal cavity and even the brain. They can eat fish fry from the inside alive and almost completely! Somehow this does not look like facultative parasitism. But that"s not all! According to recent studies, the range of "food interests" of guppy killers turned out to be quite wide: tetrahymena can parasitize not only on fish, but also on leeches, mosquito larvae, snails, tadpoles, newts and even in the bladder of dogs and the brain of children! In short, the evolutionary potential of this group of ciliates is enormous. And now there is a place to realize it. In warm-water farms in tropical countries specializing in the mass cultivation of aquarium fish, tetrahymens have found more than favorable conditions for themselves and have not failed to take advantage of them: at present, they can be found on every sixth imported guppy. On other freshwater ornamental fish they are found somewhat less frequently – only on every tenth. However, this is not a small amount – the tetrahymen reproduce at an incredible rate. You only have to bring them into an aquarium, and you will suffer a lot.
It is important for an aquarist to be able to identify fish infected with tetrahymen as early as possible. If these harmful ciliates manage to penetrate the muscles, abdominal cavity and internal organs, then it will be impossible to save the fish.
I hope that the materials presented in this work can serve as a good guide for fighting these killers. now not only guppies.
You need to know your enemy by sight. So first, let"s get to know him better:
Under extreme magnification, Tetrahymena (Tetrahymena pyriformis) is seen (from: Naim Saglam and Mustafa Sarieyyupoglu, 2002); scale: 15 µm. N stands for macronucleus, M for micronucleus, dv for digestive vacuole, and с for cytostome, or "mouth" of the ciliate.
Diagram of tetrachimen (from: USSR, 1984, Determinant of parasites of freshwater fish fauna). 1. ON; 2. Micro- and macronuclei; 3. Digestion vacuoles; 4.
In the ciliatesia life cycle, the trophon stage is one of active feeding and growth.
Tetrachimen accumulations in the muscles and under the epithelium of fish larvae are 1, 3.
2. Large trombone located beneath the epithelium.
Let’s now discuss the useful portion:
 |
| Photo 3. Understand that this fish is not difficult. The sinking of scales (however without edema of the body – dropsy) is very noticeable very well. Arrows show what to pay special attention to: "disheveled" scales, loss of individual scales and the destruction of the tail fin. |
The end of the scales itself manifests in a variety of illnesses. Additionally, it is not accompanied here. This is a defining quality. Now that you’ve noticed it, you should take a closer look at the tail. A guppy with tetrahymena has a rather distinctive appearance on its caudal fin:
 |
Photo 4. It is better to examine the tail with a magnifying glass. You can see local redness of the affected edge of the caudal fin, inflammation at its base. Ruffled scales on the caudal peduncle The rays of the tail appear whitish – they die off along the entire length (necrosis). Please note: there is practically no mucus on the body and fins |
Tetrahymena most commonly affects guppies. particularly if they are compromised by long-distance transit or the aquarium’s inability to maintain ideal hydrochemical conditions. Instead of squeezing its fins, the sick fish’s rays lighten and eventually stop. The best course of action is to perform a microscopic examination of the scraping from the fish’s body and tail so as to confirm the diagnosis:
I’ll provide more instances of sick fish. These will now be the disease’s early stages, which are treatable:
 |
| Photo 13. Initial stage of tetrahymenosis in moon gourami. Arrows point to whitish-matte areas on the fins – clusters of tetrahymena. |
 |
| Click on the photo to enlarge. Photo 14. In addition to the extensive matte areas on the fins and body of the fish (large arrows), you can see local areas of damage to the fish"s integument by tetrahymena (small arrows). |
 |
| Photo 15. Yellow tetraodon affected by tetrahymena. Early stage of the disease. A sign of the disease is the destroyed edge of the caudal fin. The fish can be saved if you start treatment immediately. |
Tetrahymena can be totally eradicated in the early stages of the illness if treatment is given to the fish right away. However, the fate of the sick fish will not be good if you put off treatment.
 |
|
| Photo 16. It all started with an almost imperceptible erosion on the body of the fish, with a matte spot, but without timely treatment, such a terrible ulcer can form at the site of the erosion in just two or three days. Of course, the role of bacteria (secondary bacterial infections) in the formation of ulcers should also be taken into account, which is important when prescribing an effective treatment regimen, but still the main culprits here are tetrahymena. They distinguish proteolytic enzymes that destroy fish tissue. The resulting "soup" Tetrachimenes are absorbed using a specialized rotary apparatus. | |
| Tetrahymena pyriformis. Drawing from a drug impregnated with silver. (from: determinant of parasites of freshwater fish fauna of the USSR, 1984). | |
A ciliary apparatus known as cyliature, or kinette, is made up of rows of cilia on the body of ciliates. Kinetosam is located at each cilia’s base. Kinetosomes are visible after coloring and are connected by a network of fibrils. Furthermore, silvering enables you to closely observe the percentes system, which is made up of merged cilia. It is made up of three memranells and an arcuate, wavy membrane. This entire oral ciliary system was referred to as a "tetrachimenium."
Tetrachimeni in spawning grounds are very dangerous. Initially, their reproduction is facilitated by decaying sex products – caviar and milk. And then they start on developing larvae. We have already seen how this happens. That is why, if after spawning the water in the spawning tank has become cloudy, and there are a lot of undeveloped eggs left on the bottom, then it is necessary to remove the dead eggs and change a sufficient amount of water to reduce organic pollution to a minimum and remove unfertilized eggs.
Tetrahymena are very little sensitive to methylene blue, so the generally accepted practice of adding it to a container with developing eggs will not prevent invasion. Tetrahymena can bring a lot of disappointment to the breeder, leaving only a few dozen, or even none, alive out of several thousand larvae.
Free-living tetrahymena feed on bacteria, which are abundant in water heavily polluted with organic matter (systematic overfeeding of fish also leads to an explosion in the number of bacteria and promotes the reproduction of tetrahymena). Absorbing bacteria one by one is not profitable. Therefore, tetrahymena are distinguished in water has a special secret that glues bacteria into small lumps. The ciliate with the help of tetrahymenium drives them to the cytostome.
It is quite reasonable to assume that the composition of the secreted secretion can be modified so that it begins to destroy the surrounding tissues of the host fish. Bacteria find a very favorable environment for themselves here and multiply rapidly, which leads to rapid progression of erosion and the appearance of deep ulcers, and tetrahymen feed on a mixture of bacteria and lysed fish tissues.
- Treatment of fish from tetrahymenosis
- Treatment of fish for tetrahymenosis in an aquarium with plants
- Video on the topic
- Mycobacteriosis or tuberculosis in aquarium fish.
- Tetrahymen from the hindgut of a discus. Microscopy at different magnifications.
- WHY GUPPIES DON"T BREED? + New Dumbo line!
- Already unbearable! Added antibiotic to the aquarium with guppies
- WHY GUPPIES GET SICK AND DIE
Treatment of fish from tetrahymenosis
Methods of combating tetrahymen are complex and include not only the destruction of the ciliates themselves, but also the suppression of concomitant bacterial infection. An excellent remedy for tetrahymen is FMS. Of the commercial products, the analogue of FMS is NILPA Aquaform, the composition is close to FMC in Kostapur by Sera, Antipar from Agrovetzashchita and AQUAYER Aquamed. Since it is necessary to fight bacteria at the same time, the combined use of such drugs as NILPA Aquaform, NILPA Acriflavin and NILPA Helamed with the simultaneous addition of furazolidone is indicated – this is in severe cases of tetrahymenosis (Alternative combination of drugs SERA costapur and SERA mycopur) . At the initial stage of the disease, NILPA Aquaform + NILPA Acriflavin can be recommended, as well as a combination of costapur and SERA baktopur in accordance with the manufacturer"s instructions.
In my practice, to combat tetrahymena, I use homemade FMS or Aquaform in combination with furazolidone and biseptol: FMS – 1 ml, furazolidone 0.5-1 g, biseptol 480 – 2 tablets – all this per 100 liters, a long bath with a replacement of at least half the volume of water at least every other day and the introduction of a full dose of all drugs. It is highly advisable to change the water and introduce drugs daily. Usually, the course of treatment lasts about a week, sometimes longer. Biseptol is a universal antibacterial agent and is well tolerated by fish without causing complications. And furazolidone should be mentioned especially. This particular medicine allows you to fight Tetrahymena living in ulcers, protected by mucus and decaying fish tissues and, possibly, those that have settled in the abdominal cavity. In such cases, dyes and formalin cannot "get" to the parasites, and furazolidone penetrates into the fish tissue. It acts similarly against ichthyophthirius . The latter, by the way, are relatives of tetrahymena – both of these groups of fish parasites belong to the class of film-stomed ciliates ( Hymenostomata ), the order Tetrahymenida (according to the classification adopted in the Identifier of parasites of freshwater fish fauna of the USSR, 1984). Furazolidone also has an antimicrobial effect, which is also important for the successful fight against tetrahymena.
Treatment of fish for tetrahymenosis in an aquarium with plants
The fight against tetrahymena in amateur aquariums with plants is particularly difficult. Furazolidone and formalin strongly inhibit higher aquatic vegetation (although also Vietnamese), so in this case it is undesirable to use these drugs. Here you can use NILPA Protocide or JBL Puntol in combination with analgin-quinine or delagyl (common drugs from the "human" pharmacies). Delagil – 4 tablets per 100 l, analgin-quinine 5 tablets per 100 l. Every other day or every two days on the third (depending on your mood to work for the benefit of the fish), after a partial water change, you need to add full doses of these drugs. Fish with ulcers and other signs of severe damage by tetrahymena should be removed and treated with levomycetin (2 g per 100 l), quinine-containing drugs and Protocide (Punktol).
About the reproduction of tetrahymena
In conclusion of the story about tetrahymena, it is necessary to explain the amazing rapidity of reproduction of these ciliates. Relatives of tetrahymena – ichthyophthirius reproduce by multiple division in the reproduction cyst. This method allows you to increase the population size faster than simple division in two. It is known that tetrahymena can reproduce also. I even suspect that for tetrahymena parasitizing fish this is the main way. Let"s look at the picture of a bream fry affected by Tetrahymena. It was made with a drawing apparatus and is a document that accurately conveys the actual observed picture. Is there at least one cell dividing in two? No! Among tetrahymena parasitizing fish, dividing individuals are very rare. On the other hand, among tetrahymena swarming in the affected tissues of fish, you can always find individuals of different sizes: small, medium and large. Small ones often have a round shape and swim slowly, medium ones are oblong and fast, large ones can also move quickly and have a typical tetrahymena appearance, but there are also large, very slowly moving ciliates that are literally stuffed with numerous spherical inclusions. Probably these are reproduction cysts. I was unable to find photographs of these cysts in the literature, so I used the word "probably" here.
 |
| Photo 17. Large, very slow moving tetrahymena from the ulcer of the moon gourami. Perhaps this is the terachimena reproduction cyst. |
When tetrahymena parasitize fish through reproduction cysts or multiple internal budding, small individuals that have recently "been born" should occasionally be found among the larger trophonts. And it is true that this. It was easy to record them on camera:
Video 3: Tetrahymena with varying dimensions, forms, and motion. 40x magnification.
I am fully aware that further research is needed on a number of topics, including tetrahymenosis diagnosis, tetrahymena biology characteristics, and strategies for controlling tetrahymena in aquariums and breeding tanks. I will therefore be happy to talk about this subject. Send a message to our forum!
Identifier of freshwater fish parasites found in USSR’s fauna. Professor O.N. Bauer served as editor. First Volume. PARASITIC PROTOZOA "Science" Leningrad, 1984.
Yu.I. Polyansky, A.A. Strelkov, and A.V. Ivanov. a comprehensive practical course on invertebrate zoology. M.: High school.
P. Bauer. Aquarium fish diseases: prevention, diagnosis, and treatment. GIPPV, "AQUARIUM," 2002.
"Bassler Biofish" published "The New Illustrated Guide to Fish Diseases" by Gerald Bassler in 2004.
"Handbook of Fish Diseases," Dieter Untergasser, t.f.H., 1989.
Saglam Naim and Sarieyupoglu Mustafa. An investigation of the holotrichous Tetrahymena pyriformis and the peritrichous Epistylis sp. found on freshwater leeches, Nephelopsis obscura. Asian Network for Scientific Information 2002 © Pakistan Journal of Biological Sciences 5 (4): 497-498, 2002.
Cherel a Jerome, André-Denis G. Wright, Michala C. Strüder-Kypke, and Denis H. Lynn. Comparative Development of Histophagy in Tetrahymena-Genus Ciliates. (www.biomedcentral.com/1471-2148/1/5). BMC Evolutionary Biology 2001, 1:5.
Tetrahymena are microscopic parasites that can infect aquarium fish of different kinds, including guppies, and cause fatal infections. For tetrahymenosis to be effectively treated and to stop the disease from spreading throughout your aquarium, it is essential to recognize the symptoms and identify the condition early through careful observation.
Fish disease: diagnosis and treatment (EDWARD J. NOGA). Press, Iowa State University, 2000.
