What is Hexamita? “Synonym Octomitus” is a very small flagellate whose length is approximately 7 to 13 microns. Under the microscope it seems to sway, back an forth. Hexamita invades the gall bladder and sometime the intestines. In severely infected animals the gall bladder becomes enlarged. Hexamita rarely occurs in ornamental aquarium fish. Therapy: medications containing Metronidazole.
Spironucleus on the other hand is commonly carried by Angelfish. These fish don’t as a rule show any ill effects from the infection, unless the protozoa leaves the intestine and attacks other organs. Then the prognosis is usually death.
However other members of the Cichlid family are a different story! Discus, Uaru and African Cichlids generally die very quickly from an infestation of Spironucleus. Some recent articles have concluded that the dreaded Angelfish Aids can be contributed to the infestation.
Spironucleus and Hexamita are spread by cross contamination of tank water. Ie: common use of infected dip nets from tank to tank. Pet shop tanks that house different species from week to week, also are a major contributor.
In Discus, Hole in the Head disease is often associated with an infection of spironucleus/hexamita as they are common at the wound site. However they are not considered the cause, only an after injury infestation.
Symptoms that you can recognize, are white thread like feces that adhere to the fish for a long time. In the case of discus and others that the disease is fatal to treatment is paramount. It can be easily controlled until it invades the internal organs. At this point the fish will most certainly die.
Medications containing Metronidazole will handle the protozoa.