Ichthyophthirius multifiliis

Ichthyophthirius, also white spot disease spot disease or semolina grain disease is a widespread parasitic disease in freshwater fish. The Ichthyophthirius is one of the most common diseases in fresh water aquariums and fish farming.

Pathogen

Trigger of Ichthyophthirius is the ciliate Ichthyophthirius multifiliis. This world occurring ectoparasite achieved in its vegetative form a size up to 1 mm. The salient features are a large horseshoe-shaped nucleus and a small round nucleus.

The parasite lives in the epidermis or the epithelium of the gills of its host in outwardly closed cavities. Is he matured into reproductive capacity he breaks the skin and leaves the host, which suffers this serious skin injury. In the water Ichthyophthirius multifiliis sinks to the bottom, settles there and begins with the formation of cysts. In these divisions see repeated in up to 1,000 so-called fanatics instead ( Tomiten ) of 50 to 70 micron size. The swarm is again capable of invasion for fish, but must find a host within 70 hours. The duration of the proliferation process is temperature-dependent, at four degrees Celsius it takes about six days at 25 to 28 degrees centigrade only ten to twelve hours. Especially in tropical aquariums can then give rise to an explosive growth with corresponding prevalences.

Symptoms

Infected fish have to pinhead-sized, white nodules all over the body, the fins and the gills. In severe cases, nodules may combine to gray areas. The affected fish often show difficulty in breathing, " clamped fins " and violent scouring movements. As a result, the fish is increasingly apathetic and becomes emaciated.

Therapy

During its growth phase in the skin of the host, the parasite is to not fight directly. The treatment is thus directed against the free-swimming enthusiast and must be repeated two to three times. In aquariums can supportive the water temperature increased slightly to shorten the development phase as protected cyst. As a medicine for aquarium fish is suitable the malachite green very effective, farmed fish can be treated with formalin and potassium permanganate. Fish that survive Ichthyophthirius, develop a stable immunity.