Oodinium
Encyclopedia
Microscopic
The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:...
parasitic dinoflagellates. They live off salt
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...
and fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, causing a type of fish velvet disease (also called gold dust disease). One species has also been recorded on various cnidaria
Cnidaria
Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...
ns http://www.int-res.com/articles/dao/10/d010p211.pdf.
The host typically develops small yellow or gold dust scattered on its head, fins and body. At this stage, the infestation is already severe. The attack usually starts at the gills at which stage it is difficult to notice. The host is irritated and often swims in fuzziness while rubbing itself against rocks. The yellowish spots are more vivid under sunlight or flashlight. It is very similar to Ichthyophthirius
Ichthyophthirius
Ichthyophthirius multifiliis is a common disease of freshwater fish. It is caused by the protozoa Ichtyopthirius. Ich is one of the most common and persistent diseases.The protozoan is an ectoparasite...
, though the oodinium spots are yellowish and smaller.
The life cycle
Biological life cycle
A life cycle is a period involving all different generations of a species succeeding each other through means of reproduction, whether through asexual reproduction or sexual reproduction...
of oodinium starts as a dinospore that swims in the water to look for a suitable host. As it attaches itself onto the host skin, it forms a hard shell protecting itself against the outside environment while it is eating the fish skin cells. This is the cyst stage seen as dust covering the fish skin. After few days, the cyst sinks to the bottom, freeing new generation of dinospores. And the cycle repeats. The dinospore must find a host within 48 hours, otherwise the dinospore would die.
Treatment is possible by diluting the commercially available copper salts. Free swimming dinospore is extremely vulnerable to copper. Bringing the water temperature to 30°C helps to release the dinospore from cyst
Cyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
.