What triggers dormant tomonts to release tomites?

[davidfrances]

OK, so I understand this:

Once the protomont attaches to a surface, it begins to encyst and is now called a tomont. Division inside the cyst into hundreds of daughter parasites, called tomites, begins shortly thereafter. This noninfectious stage can last anywhere from three to twenty-eight days. During this extended period, the parasite cyst is lying in wait for a host. After this period, the tomites hatch and begin swimming around, looking for a fish host. At this point, they are called theronts, and they must find a host within twenty-four hours or die.

I understand tomonts may concentrate in sleeping areas, that's one reason fish are constantly being reinfected. But during a fallow period, in the absence of fish hosts, what triggers the tormont to release tormites?

 

[Psionicdragon]

I would assume temperature, light, and nature.

 

[sleepydoc]

I don't think it's known, definitively. I think it's primarily time/genetics/the parasite's own internal clock. That's why the fallow time recommendation is so long (and there's so much debate and inconsistency over it.) we know what the 'normal' time is, an assume it follows a normal distribution, so we can say that at 3 standard deviations there's a 99.7 % chance that all of them have hatched.

Snorvich should likely give a more definitive answer, but that's my understanding.

 

[Mrscribbled]

Although temperature may possibly have some effect on the speed of the life cycle, there is nothing that triggers tomonts to rupture.

 

[snorvich]

The reason tomonts excyst is simply a biological imperative to reproduce. Some strains of Cryptocaryon irritans are salinity insensitive but all tend to be somewhat sensitive to lower temperatures. Those strains that are temperature sensitive have tomonts delaying the urge to excyst (and hence reproduce).

The life cycle and salinity tolerance of Cryptocaryon irritans has been studied rather extensively; there have also been numerous studies with regard to environment temperature, at least at those temperatures where fish are normally found. Trophonts invariably completed their growth phase on the host in 3 to 7 days, a range upon which tank transfer as a prophylactic process has been designed. . The reproductive process of the tomonts yielded tomites as early as 3 and as
late as 28 days which was correlated with ambient temperature; cooler temperatures correlate with longer time for tomonts to produce tomites. Tomite life span was invariably 24 to 48 hours.