Latin name: Other names: Gas Bubble Disease Pathogen: Symptoms:
An autopsy of relatively big fish shows blood froth coming from blood vessels,
High sensitivity to mechanical irritants,
Brightening (lighting) of body colors,
Darkening of body color (Black discoloration),
Opacification of the cornea (keratoleukoma, nebula),
Separation of fin rays
Fish show signs of anxiety, actively react to external irritants (knock against the aquarium walls, react to the approaching net). Affected fish lose equilibrium, shake and tremble. They turn a dark color, sometimes color will fade. Gill covers will move slowly and eventually stop moving. Another sign to look out for is scale protrusion which will start in the caudal peduncle and will gradually spread thought the whole body. Affected fish may show darkening of the cornea, pop-eye that will cause blindness, fin erosion (only fin rays will remain). Bubbles on the aquarium walls may be indicative of embolism. An autopsy of relatively big fish will show frothy blood coming from blood vessels, parenchymatous organs (visceral organs that have no cavities and that consist only of parenchyma Ц liver, spleen, kidneys), and gills. This is caused by the build-up of bubbles in them.
Sometimes gas embolism or gas bubble disease will occur in the aquarium. It is caused by the active production of oxygen by plants and at the same insufficient artificial aeration as well as by the use of unsettled tap water. Disease develops if oxygen and nitrogen levels in the water are excessively high.
Disease is caused by oxygen oversaturation: a large number of small bubbles of oxygen form within the circulatory system and block blood flow as they are bigger in diameter than the capillaries (the smallest type of blood vessel in the body). The blockage occurs because the cardiac impulse is not strong enough to push the gas through the capillaries. Diagnosis is made on the basis of clinical signs, pathologicoanatomic changes which are revealed during the autopsy, and by measuring the level of dissolved oxygen in the water
Tests carried out with Guppies, Mollienesia, black Mollienesia, Tetra-von-rio, and cardinals, showed that if the concentration of oxygen in the water is between 28 and 30 mg/L, fish die within 1.5 Ц 2 hours of symptoms onset.
How to cure:
Fish should be placed into the aquarium where the concentration of oxygen in the water does not exceed 10-15 mg/L, for example, into chilled boiled water or settled water (that stood for 2-5 days).
To prevent the disease avoid intensive water aeration of the aquarium which contains a lot of plants and with lightening is very bright.