Causative agent: Trichodina spp. — disc-shaped mobile ciliate protozoan
Trichodina is a disc-shaped ciliate protozoan that can be found in most aquariums in small numbers without causing problems — it is when stress, poor water quality, or overcrowding allows the population to explode that Trichodina becomes a disease. The parasite uses a ring of tiny hooks to attach to and glide across the fish's skin and gills, feeding on bacteria and organic matter but causing irritation, mucus overproduction, and in heavy infestations, significant tissue damage. In Australian aquariums, Trichodina is most often diagnosed in goldfish, koi, and juvenile fish that are kept in suboptimal conditions. The treatment approach is twofold: address the water quality and stocking issues that allowed the outbreak, and treat with salt baths or Aquasonic Bactonex to reduce the parasite load. Trichodina is an indicator that something is wrong with the tank environment, and simply medicating without fixing the underlying conditions will result in rapid reinfestation.
Symptoms
- •Scratching and flashing
- •clamped fins
- •excess mucus on skin
- •rapid breathing
- •greyish or white patches on skin
- •lethargy
- •loss of appetite
- •fin erosion
Treatment
- •Salt baths
- •formalin
- •malachite green
- •improve water quality and reduce stocking density
- •treat full tank
Australian Medications
- •Aquasonic Bactonex
- •Aquasonic Ichonex
- •Aquasonic Methylene Blue
Commonly Affected Fish
- •All freshwater fish
- •goldfish, koi, and young fish are commonly affected
Important Notes
Trichodina outbreaks are a symptom of poor water conditions. Fixing the environment is as important as medication.