Saprolegnia: causes and treatment.
Cold water fish are prone to Saprolegniasis Commonly known as mycotic diseases or mycoses, they are actually infections caused by the presence of aquatic fungi, mainly Saprolegniales (Saprolegniasis), as it is the most common among ornamental fish and their spawns. without ruling out other types such as Achlya and Aphanomyces.
Although many of the species of fungi feed on dead organic matter, contributing to its decomposition, there are species such as those mentioned that are parasites of other organisms. In the case of the Saprolegnia, they produce the infection by parasitizing the fish and entering its tissues through open wounds.
The disease known as cotton disease is usually treated and known as a parasitic fungal invasion when the causative organism is actually a bacterium called Flexibacter.
The presence of fungi parasitizing a host is relatively easy to determine due to the white or grayish cottony excretions present in the affected areas. At first, the invasion occurs in limited areas to later invade, if no remedy is found, the rest of the victim’s body. These pathologies are common in freshwater ornamental fish and are not so common in marine aquariums, since salt itself is an excellent fungicide.
The presence of fungi parasitizing a host is relatively easy to determine due to the white or grayish cottony excretions present in the affected areas. At first, the invasion occurs in limited areas to later invade, if no remedy is found, the rest of the victim’s body. These pathologies are common in freshwater ornamental fish and are not so common in marine aquariums, since salt itself is an excellent fungicide. Cold water fish are prone to Saprolegniasis
Causes of Saprolegnia
While Saprolegnia may be present in your aquarium water at any given time and not cause problems among your healthy fish, there are predisposing factors that increase the likelihood of infection. These include:
Poor Water Quality: Fish swimming in contaminated water (from algae and debris) are more vulnerable to many illnesses. The chronic stress caused by trying to maintain homeostasis in poor-quality water leads to decreased immune function, making it much easier for bacteria, other fungi, and parasites to take hold and cause disease.
Inappropriate Temperature: A tropical tank that is kept too cool or experiences a sudden drop in temperature can cause an increased incidence of Saprolegnia infections.
Immunosuppressed Fish: Some fish do not have the robust immune capabilities of their counterparts and are more susceptible to different diseases. By noting individual fish differences in disease susceptibility, you can catch early signs of disease by monitoring “weaker” fish. These fish with compromised immune systems may be more susceptible to opportunistic pathogens such as Saprolegnia.
The mucosa, in perfect condition, that covers the skin of the fish is a barrier to fungal spores that roam freely in the water permanently. Situations that alter this protection result in an entry route for invasion. For example poor maintenance conditions, bacterial infections or injuries from fights are common causes.
Among the species most likely to suffer from this type of condition are the so-called cold water species.
The infestation produces ulcerations and tissue destruction due to the necrotic action carried out by the fungi prior to assimilating them as a food source. Mild infections do not usually cause death in the affected animal, however generalized infections become dangerous by destroying the external tissues and altering the internal osmoregulation of the animal.
The presence of fungi is one of the main causes of the loss of complete clutches of eggs as they are highly contagious. In these cases, except for those supervised by the parents who will eliminate the affected eggs, the fancier must take measures so that the rest of the laying is not affected. We can detect affected eggs by their opaque appearance.
The first action we must take is to determine the alteration that is causing the loss of the animal’s defense capacity. Once the source of the problem has been determined and corrected, it is time to treat the affected animals.
In those cases with a serious infection it is advisable to treat in a separate aquarium. The products to be used in the specialized market are varied and effective. However, special care must be taken and the prospectus must be read before applying it, since there are numerous species that do not tolerate the chemical components of these drugs well.
Methylene blue: This compound is used as an antiseptic, but it has low effectiveness, it is used as a preventive when an injury occurs, it is also used to protect eggs from saprolegnia at a rate of 1 drop per 0.27 gallons, with methylene blue at a concentration of 2%, to have optimal results in laying it is essential to have an adequate concentration of oxygen, usually a diffuser is placed near the eggs at saturation.
Formaldehyde: It is a compound that is not used frequently due to problems with overdoses, the best way to use this product is in baths carried out with adequate time and concentration precautions, usually 30% or 40% formaldehyde is used. at a rate of 2 ml per 0.27 gallons of water, the time that the affected fish is kept is 5 minutes, if the fish shows signs of intolerance, the bath must be interrupted immediately.
Salt: This element has to be as natural as possible, it does not have to contain iodine, this compound is used in baths made with an adequate precaution of time and concentration, an adequate concentration is 10 grams per 0.27 gallons of water, the same time that the formalin will be 5 minutes, this concentration can be tolerated by a wide variety of fish including those intolerant, but you must always be watching the fish, at any sign of discomfort.
Nystatin: It is an antifungal used in humans, it can be used without problems in tropical fish, it can be added in the main aquarium since it does not eliminate beneficial bacteria, but the best way to apply it is in the hospital aquarium, it is sold in the pharmacy As tablets or ovules, the tablets contain 500,000 IU (international units) of nystatin and the ovules contain 100,000 IU of nystatin. You have to pay attention when buying the medicine if it comes in tablets or ovules, since the tablets have 5 times the nystatin concentration. The dose to use is 100,000 IU per 5.28 gallons of aquarium water, if you buy the ovules you will not have a problem, you just have to dissolve one in a little aquarium water and apply it to each ovule for the 2.64 gallons.
Ketoconazole: It is also a very good antifungal Ketoconazole Aquatic Antibiotics (Fish Fungus) 200MG – 30 Capsules and can be used without problem in tropical fish, it is sold in pharmacies in 200 mg tablets, the dose to use is one tablet (200 mg) per 8 gallons of water, it can also be take 50 mg per 0.27 gallons of water in baths, making things a little easier, it is one tablet per 1 gallon of water, the bath time will be 5 to 10 minutes, we have to be aware of any intolerance that may occur the affected fish.
Naxogin compositum: This medicine is three in one, it is a powerful antifungal, antibacterial and antiprotozoal, this medicine is very useful since saprolegnia is always associated with both bacteria and protozoa. It is sold in pharmacies in tablets, each package treats 6, the way to apply it, (that is, always in the hospital aquarium since this medicine contains chloramphenicol that eliminates bacteria) is one tablet per 6.60 gallons of aquarium water, the tablets They are dissolved in a little water and then added.