November 27, Picture this. Maybe you just added some fish from the pet store. Either way, your excitement soon turns to alarm when you notice your fish acting strangely. Even more alarming are the little white spots all over your fish.
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November 27, Picture this. Maybe you just added some fish from the pet store. Either way, your excitement soon turns to alarm when you notice your fish acting strangely. Even more alarming are the little white spots all over your fish. Ichthyophthirius multifiliis or white spot disease is one of the most common and persistent fish diseases. This resource has been created to teach fish keepers everything they need to know about Ich. What Exactly is Ich? Ichthyophthirius multifiliis is a parasitic protozoa that causes Ichthyophthiriasis.
Ich is an obligate parasite, meaning it must have a fish host to survive. Although parts of its lifecycle are spent in the open water. This protozoan has multiple life cycles. The most notable being the phase where it causes visible white cysts. Ich likely originated in Asia and was introduced to Europe in the middle ages. It later spread to North America and the rest of the world through the goldfish trade source. Ich Life Cycle In order to prevent and treat Ich we need to first understand its life cycle.
The three distinct life stages of Ich are the tomont, theront, and trophont. Life Cycle Stages of Ichthyophthirius multifiliis 1. Dividing tomites within cyst on fish Tomont When a trophont leaves an infected fish it becomes a protomont. These protomonts will attach to any available surface and form thin-walled cysts called tomonts. Within the tomonts are tomites.
These are the reproductive start of a new life cycle for Ich. They can be thought of as eggs that will later hatch and start a new life cycle. Within the safety of these cysts the tomite cells will divide multiple times to produce anywhere from to 1, theronts per cyst. Theront The theront is the infectious stage of Ich. Once they are mature in the tomite cyst they bore their way out and are released into the water. At this stage, the theronts are mobile and can swim in search of a host fish.
This swimming is performed with cell appendages called cilia. These motile cilia are hairlike appendages that beat in coordinated waves providing motion. This is accomplished by the theront using its penetrating gland and strong swimming action.
Theronts must find a host within 2 to 3 days. If they are not able to find a host in this time period they will soon die. This is also the stage that Ich is vulnerable to treatments. Trophont Once the theront finds and burrows into its host fish it becomes a trophont. These trophonts will begin to feed on the fish. This feeding causes tissue damage to the fish and will eventually lead to death. These cysts create the visible white spots that Ich is known for.
In this protective cyst, it is protected from all known treatments meant to eradicate Ich. Once it has fully matured it will leave the fish to form a tomont and the cycle repeats.
Life Cycle Timeframe The rate or time it takes Ich to complete this cycle varies. The main factor that determines this life cycle speed is water temperature. This is important to remember as this is one strategy in combating Ich. How does Ich kill fish? But it does cause a host of issues for the fish that leave it in a weakened and stressed state. The gills are especially vulnerable to Ich infestation.
Once infested the gill cells will thicken and deform. This results in a restriction in oxygen uptake by the gills. This suffocation is why fish infected with Ich will often be found by water inlets or bubblers. The fish will seek out these higher oxygen areas in an attempt to breathe. The damage goes beyond the gills. This can leave the fish prone to secondary infections. All of this results in a very stressed fish that is far more susceptible to mortality from a variety of causes.
Identifying Ich Now that we understand Ich, how do we positively identify it? The primary way Ich is identified is by the telltale white spots it leaves on fish. In a full-on outbreak, they will likely have these spots all over their bodies.
Some people say it makes the fish look like they have been sprinkled with salt. Other times, however, there will only be white spots on the gills of the fish.
As the infection takes hold, changes in behavior will also start to become apparent. One of the first behaviors exhibited by a sick fish will be rubbing or scratching against things. This behavior will sometimes look frantic or violent. As the disease progresses further the fish will become sluggish and refuse to eat.
They will often congregate around water filter outlets or airstones. The fish do this because they are having difficulty breathing and these areas have more oxygen. Ich is sometimes confused with Lymphocystis. With this disease, however, the white spots tend to be more clustered around the fins. If there is any doubt the only sure way to identify the disease is for a qualified veterinarian to take a sample and examine it.
The best way to deal with it is to never get it in the first place. Prevention is key! The single best way to prevent Ich in your aquarium is to quarantine all new fish or live plants. This will require an extra aquarium but it need not be large or extravagant.
There are a wide variety of diseases that can hitch a ride on your new fish or plants. For this reason, it is best to quarantine them for at least 4 weeks but longer is better. During this time most diseases should reveal themselves. With live plants its best to buy them from tanks without fish. Other prevention measures are focused on preventing stress. This includes minimizing transport time, not overstocking your tank, regular water changes, and so on.
How to Treat Ich So what do we do once we have identified an Ich outbreak? Treatment is essential for the survival of every fish in the aquarium. As I alluded to earlier when talking about life cycle stages, Ich cannot be treated once it has infected the fish. The cysts that are formed on the fish provide a protective layer for the trophont.
So what do we do once we have identified an Ich outbreak? What needs to be done is to interrupt the life cycle of Ich. Ich can only be effectively killed in the open water theront stage. Because of this, multiple treatments will need to be performed to catch any newly hatched theronts.
There are a variety of ways to interrupt and kill Ich during this vulnerable lifecycle stage. Even with effective treatment, your fish will still be stressed and some may still die. Using heat on its own is generally the easiest and safest way to treat for Ich. But it may not be the most effective. This increased temperature should be maintained for days. After this period the temperature can be gradually reduced back down at the same rate.
Be aware that warmer water holds less dissolved oxygen. To make this worse fish infected with Ich are already having a hard time breathing. With this in mind, you need to add more aeration to the water. If you already have one increase the output or add a second. There is some disagreement about the effectiveness of using heat alone.
Some have had great success with it and some have not. To increase the effectiveness of using heat salt can be added as well. This is explained below. Treating Ich with Salt Using salt in conjunction with heat will increase the effectiveness of the treatment.
This is a harsher treatment however and should not be used with some soft water species such as Cories.
Ich & White Spot Disease – Cause, Prevention, and Cures
All freshwater fish can be infected although species vary in their susceptibility to the disease. Infections have been reported from all regions where fish are cultured and in feral fish populations in all continents. The parasite attacks the epidermis of the skin and fins, the gill filaments and the cornea and can kill fish by interfering with their gill function and osmoregulation. Outbreaks occur when conditions are favourable for rapid multiplication of the parasite.
How to Treat Ich (Ichthyophthirius Multifilis) in Aquarium Fish
Two juvenile clown loaches with ich Scanning electron microscope image of Ichthyophthirius multifiliis theront photo: Ole S. The diagnosis can be confirmed by microscopic examination of skin and gill smears. Scrapings of skin, fins or gill surfaces using a cover slip or scalpel and subsequent mounting on a microscope slide with a few drops of water under a cover slip should be examined under the light microscope x magnification. The trophont is slowly rotating, covered by rapidly beating cilia and has a prominent, horseshoe-shaped macro-nucleus. Ichthyophthirius multifiliis Chemicals and medicines[ edit ] Various chemotherapeutants can be applied for the treatment of infected fish and infected fish farm systems but caution should always be observed during any treatment. Some drugs are toxic to certain fish species and any treatment method must take into account the species of fish some will not tolerate certain medications.