Freshwater Fish Diseases

Freshwater fish constitute 41% of the known species of fish. They dwell in freshwaters like lakes and rivers where the salinity is as less as 0.05%. Most of them make good aquarium fish. But these fish are quite prone to diseases. Fish care is an important activity when breeding fish in aquariums or fish tanks.

Fish Health Issues
Most of the tropical fish diseases are due to bacterial, fungal, protozoan or parasitic infections. External factors like lack of oxygen or chemical poisoning and physical wounds can also result in infections.

Freshwater Fish Diseases	Infection Type	Symptoms	Treatment
Fish Fungus	Fungal	Gray colored or white colored growths appear on the scales of the fish. This fungal infection is caused by water molds. The most common water mold that affects fish is a filamentous fungi known as saprolegnia. This infects the fish by secreting digestive enzymes on the tissue of the body thereby absorbing all the nutrients of the fish.	Medications like Jungle Labs Binox Crystal can be used to protect fish from such fungal afflictions. Cleaning and recycling the aquarium water is advised.
Ichthyophtirius/White spot/Ich	Protozoan	This is a protozoan infection caused by protozoa Ichtyopthirius. Symptoms can be identified by the development of small white spots on the fins and on skin of the body. This gives an appearance of salt coating on the body of fish. The protozoan primarily starts feeding on the epithelial tissue of the fish gills. It rapidly multiplies by binary division. Betta fish are most susceptible to this protozoan infection.	To prevent any further multiplication of Ich protozoan, it is important to maintain the aquarium water at a temperature 25-82 F. The increase in temperature speeds up the life cycle of the protozoan thereby mitigating its multiplication. Medications containing copper and malachite green are recommended to cure the fish suffering from Ich. Water treatments like Aquarisol are also given to eliminate protozoans causing infections.
Fin Rot	Bacterial	Symptoms like loss of appetite, inactivity and rotting fins can lead to believe that the fish is suffering the infection of fin rot (caused by Pseudomonas fluorescens).	The main reason for this infection is smutty water conditions. Clean the water regularly and remove any carbon content before using any kind of medication as carbon absorbs the medication. Antibiotics like tetracycline, penicillin, amoxicillin or erythromycin can be used for fish treatment.
Malawi Bloat/Dropsy	Bacterial	This bacterial infection is diagnosed by signs of swollen abdomen, lethargy and discoloration of fish.	Proper fish food is an important part of your fish care because Malawi bloat is often caused by malnutrition as well. To prevent further bacterial infection, water change must be done on a regular basis.
Pop-Eye	Bacterial	As the name suggests, the eyes of the fish bulge out due to fluid accumulation in the eye. If the symptoms are overlooked, the fish may start looking gross. Goldfish are the most common fish to get afflicted with pop eye fish disease.	In such cases, the fish can be quarantined. A natural cure that can slow down the infection is adding Epsom salt to the aquarium water. The ratio must be 1 Tablespoon of Epsom salt for 5 gallons of water. A 50% water change is mandatory to prevent further aggravation of the bacterial infection. Anti bacterial treatments such as maracyn and esha 2000 are also recommended.
Swim Bladder Disease	Parasitic	Swim bladder is an internal organ of the fish that helps it to float in the normal depth without having to swim for long. Basically it promotes the buoyancy factor. When the swim bladder gets infected, the signs of swim bladder disease become apparent with fish not moving much. They usually tend to stay in the bottom of the tank or float on surface.	10% water change a week is recommended. To combat the infection and improve digestion process, fish are fed with peas for treatment.
Head and Lateral Line Erosion - HLLE	Bacterial	The symptoms of this infection can be identified by the appearance of small gray lesions that start around the eye and head and spreads all the way across the lateral line of the body.	Fish must be fed with rich vitamin supplements containing vitamin A, vitamin C and vitamin D. Also the aquarium water must be devoid of carbon particles which can aggravate the lesions by irritating the skin of the fish.
Velvet (caused by oodinium parasite)	Parasitic	This resembles Ich. However the signs of velvet become apparent with the appearance of yellow or gray dusty spots on the skin of the fish. Infected fish usually have the tendency to flap the gills rapidly and rub them against the glass of the tank.	Water should be diluted with copper salt. Aquarisol is recommended for the treatment of this infection.
Oxygen Starvation	External Factors	The fish might frequently swim up to the surface and gulp down the water. This indicates there is not enough oxygen in the tank.	Aeration needs to be increased within the tank. This can be done by adding some aquarium furniture like airstones and powerheads to the tank to increase the flow of the filters. If the temperature of the water is higher than normal, add a few ice cubes to the tank.
Ammonia Poisoning/Nitrate Poisoning	External factors	The first sign of ammonia/nitrate poisoning is the deep red coloration of gills. The gills also might swell due to the poisoning. The fish might exhibit traits of lethargy and might frequently swim up to the surface gasping for oxygen.	Water change is the immediate step to be taken. About 1/3rd water has to be recycled. Cleaning and filtering the aquarium on a regular basis is one of the important tips on aquarium maintenance.

Fish Care
The above mentioned diseases are some of the common aquarium fish diseases. They are curable with proper remedies and treatments as stated above. Whenever a health issue is identified in fish, the first action should be to isolate the fish to prevent a contagion. The infected fish can be put in an isolated hospital tank where the water is diluted with medication salts like Epsom salt or formalin. Once the fish gets better, it can be moved back to the former tank. But before you do that, make a point to disinfect the tank with potassium permanganate. At times, heat therapy is also suggested as an effective treatment for parasitic and fungal infections.

Breeding fish in aquariums and fish tanks is definitely fun but challenging. Fish are delicate creatures and need proper food and care. Otherwise they are highly susceptible to diseases. It is also important to monitor the fish and their daily activities to understand any unusual symptoms in them.