Piscinoodinium pillulare
| Piscinoodinium pillulare | ||||||||||||
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| Piscinoodinium pillulare | ||||||||||||
| ( Schäperclaus , 1954) |
Piscinoodinium pillulare ( synonym : Oodinium pillularis ) is a fish pathogenic, unicellular dinoflagellate and is considered to be the cause of the parasitosis velvet disease (also called oodinosis , coral fish disease and pillularis disease )occurring in freshwater fish. P. pillulare reaches a size of more than 0.1 mm on fish.
Appearance and way of life
Under the microscope, Piscinoodinium pillulare appears as a bubble or urn-shaped, rounded structure of yellowish to brown color and its thinner end sits firmly on the mucous membrane of the fish. P. pillulare hangs together in large to smaller, grape-like groups and is firmly anchored in the fish skin with root-like plasma threads ( rhizoid ). If the parasite, which is 30 to 140 µm in size, grows to a size of more than 100 µm in the parasitic stage, it becomes visible to the naked eye and appears as a light, whitish dot. At this point, P. pillulare can easily be compared to the ciliate Ichthyophthirius multifiliis , the The causative agent of ichthyophthiriosis , better known as white spot disease, can be confused because both parasites cause similar symptoms during the course of the disease.
Towards the end of its parasitic life, P. pillulare separates from its host and sinks to the bottom. There the parasite loosens itself and begins a multiple division. The up to 256 daughter cells develop into a flagellated dinoflagellate about 15 μm in size during the last division. One of these flagella protrudes from the cell surface and is used by P. pillulare for locomotion. If the (without flagella) 7 to 10 µm large dinospores fail to find a suitable host within 24 hours, they die. During this time dinospores can also be found on snails, but they are not attacked by P. pilluare and are only used for transport purposes. If the parasite finds a suitable host, it attaches itself and sheds the flagella.
swell
- Rudolf W. Hoffmann: Fish diseases . Eugen Ulmer, Stuttgart 2005, ISBN 3-8252-8241-4 .
- Dieter Untergasser: Diseases of the aquarium fish . Franckh-Kosmos, Stuttgart 2006, ISBN 3-440-10264-5 , pp. 106-107.
- Rüdiger Spangenberg: Oodinium infestation (Oodinosis). In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. 2 volumes. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 720.
Web links
Individual evidence
- ↑ a b Rüdiger Spangenberg: Oodinium infestation (oodinosis). In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 720.