Velvet (fish disease)
Velvet sickness, conjointly referred to as atomic number 79 sickness, may be a fish sickness caused by flagellate parasites of the genus Piscinoodinium, which provides the fish a dust-covered, slimy look. The sickness happens most typically in tropical and (to a lesser extent) marine aquaria.
Life cycle:
The acellular parasite's life cycle will be divided into 3 major phases. First, as a tomont, the parasite rests at the water's floor and divides into as several as 256 tomites. Second, these juvenile, motile tomites swim concerning in search of a fish host, meantime mistreatment chemical action to grow, and to fuel their search. Finally, the adolescent tomite finds and enters the slime coat of a number fish, dissolving and overwhelming the host's cells, and needing solely 3 days to achieve full maturity before detaching to become a tomont all over again.
Pathology:
Velvet (in associate marine museum environment) is typically unfold by contaminated tanks, fish, and tools (such as nets or testing supplies). There are rare reports of frozen live foods (such as bloodworms) containing dormant varieties of the species. Frequently, however, the parasite is endemic to a fish, and solely causes an obvious "outbreak" once the fish's system is compromised for a few different reason. The sickness is very contagious and may prove fatal to fish.
Symptoms:
Initially, infected fish area unit acknowledged to "flash", or periodically dart from one finish of associate marine museum to a different, scratching against objects so as to alleviate their discomfort. they're going to conjointly "clamp" their fins terribly near their body, and exhibit lethargy. If untreated, a 'dusting' of particles (which area unit actually the parasites) are seen everywhere the infected fish, go in color from brown to gold to inexperienced. within the most advanced stages, fish can have problem respirating, can typically refuse food, and can eventually die of drive attributable to mortification of their gill tissue.
Treatment:
Sodium chloride is believed to mitigate the copy of Velvet, but this treatment isn't itself ample for the entire demolition of an endemic. Additional, common medications adscititious on to the fish's surroundings embrace copper sulphate, methylthionine chloride, formalin, mineral inexperienced and acriflavin, all of which might be found in common fish medications designed specifically to combat this sickness. in addition, as a result of Velvet parasites derive a little of their energy from chemical action, exploit a tank in darkness for seven days provides a useful supplement to chemical curatives. Finally, some enthusiasts suggest raising the water temperature of associate infected fish's surroundings, so as to quicken the life cycle (and ensuant death) of Velvet parasites; but this maneuver isn't sensible for all fish, and will induce immu no com promising stress.
