Are some fish "immune" to ich?

M

MikeG

Premium Member
Just had a four month battle with my PBT which did succumb last week. He was eating a half sheet of nori/day very active but showed signed of worsening infection. Eventually he stopped eating and was dead in 24 hrs.

I'm running a sps with stable parameters for sps (alk, ca, temp).

My question is I only have a 2.5" GSM in the tank which has never shown visible signs of infection. Should I remove him and let the tank be without fish/hosts for 8-10 weeks or leave him in?

I am also running uv

Thanks
 
While some (perhaps 5%) of fish can develop an immunity to ich, they still carry the parasite, and the immunity only lasts six months. Some fish are ich resistant either because of their habits or their slime coat. Fish do not have to exhibit ich symptoms in order to have ich.
 
Thanks for the quick reply.

So the clown prob has it. So he needs to be removed and treated.

Why don't the tertiary signs (white spots) present? Isn't it a final sign of the fish healing itself? Where are the parsites on the fish then?
 
MikeG said:
Thanks for the quick reply.

So the clown prob has it. So he needs to be removed and treated.

Why don't the tertiary signs (white spots) present? Isn't it a final sign of the fish healing itself? Where are the parsites on the fish then?
Click to expand...

While white spots that look like salt are definitive for diagnosing ich, they are not necessarily present. Usually, but not always, ich is initially present in the gills.
 
Fish that seem immune to classic symptoms are not immune, just carriers. I'm not sure there is any documented evidence that fish actually become immune (parasite free, regardless of the parasite location... gills etc) to ich, just resistant.
 
Thanks Peter,

So you recommend removing the fish, treat him with hyposalinity, and leave the display "fish free" for about 2 months?
 
I seem to recall reading research about one species of rabbitfish secreting a protein lethal to crypto in its mucus, though I can't recall whether it was produced by the fish's immune response or if it was genetic.

I'd imagine the way rabbitfish and some other maintain their slime coats (relatively thick and coherent layer of mucus, shed in large sheets fairly frequently) would naturally make them rather resistant to infection.

Given its relatively low kill rate in the wild, ich doesn't really exert strong selective pressure on marine fishes, so there isn't really much "incentive" for a population to develop a new physical trait which grants them immunity.
 
According to marine biology literature:

"As is seen with other diseases, general fish health and environmental factors including water quality will affect the status of the fish's immune system and may worsen the effects of an infection. If the immune status of the fish is compromised or if environmental factors are less than optimal, Cryptocaryon infection will be even more explosive and harmful. People that advocate boosting the immune system make survival more probable, but this does not rid the tank of Cryptocaryon irritans.

Fish that survive a Cryptocaryon infection develop immunity to that particular strain of Cryptocaryon, which can prevent significant disease reoccurrence for up to 6 months (Burgess 1992; Burgess and Matthews 1995). However, these survivors may act as carriers and provide a reservoir for future outbreaks (Colorni and Burgess 1997)."

This was mentioned in one of the ich stickies. Note that there are multiple strains of cryptocaryon irritans and this temporary immunity applies to only one strain. This is not really ich resistance such as found with mandarins and other fish protected by a resistant slime coat, and the immunity is only temporary.
 
MikeG said:
My question is I only have a 2.5" GSM in the tank which has never shown visible signs of infection. Should I remove him and let the tank be without fish/hosts for 8-10 weeks or leave him in?

I am also running uv
Click to expand...


it's tough to eradicate a system of the parasite depending on the strain.
fallowing for 10 weeks can reduce the population but no guarantee of full eradication. if yoiu plan on getting more tangs then leave fallow for at least 12 weeks and hope for the best. the UV should help there.
 
Thanks everyone for the replies.

I didn't know there were strains that could live without a host for more than 8-10 weeks. I guess another two weeks won't hurt but even then you think I might have the same problem. Wow

So even if I set up a quarantine tank now I'm in no way positive it won't come back. That's terrible.
 
MikeG said:
Thanks everyone for the replies.

I didn't know there were strains that could live without a host for more than 8-10 weeks.
Click to expand...

Actually, it is a stage of the life cycle (although different strains also have variable back ends to the life cycle). The time required for theront development varies. In one study (Colorni and Burgess 1997), theronts (stage vulnerable to hyposalinity and chemical treatment) emerged from a group of tomonts sometime between 3 and 72 days, with most released from 4 to 8 days after tomont formation. In another study (Diggles and Lester 1996c ), tomite development and theront release occurred, on average, between 5 and 12.1 days after tomont formation, depending upon strain and temperature. There was no correlation between tomont size and theront release.
 
I run my tank around 76-77 F. Wondering if I should turn it up (gradually) to 79 to speed up the life-cycle. Wouldn't be bad for my sps either
 
People that advocate boosting the immune system make survival more probable, but this does not rid the tank of Cryptocaryon irritans.
Click to expand...

Wow, Snorvich, I can't believe it, I actually agree with you on this. :wave:
 
MikeG said:
I run my tank around 76-77 F. Wondering if I should turn it up (gradually) to 79 to speed up the life-cycle. Wouldn't be bad for my sps either
Click to expand...

Raising temperature within the range that is "feasible" would have no effect on life cycle. that is a carryover from fresh water ich days.
 
You must log in or register to reply here.

Similar threads

BigEZ77
Urgent Help Requested - Wrasses Won't Come Out - CB Blue Tang Arriving Today (NO QT)
Replies
8
Views
634
rrrrob
rrrrob
C
Help with fish illness diagnosis
Replies
4
Views
576
Dr. Reef
Dr. Reef
Paul B
IMO How to set up a tank to stay healthy and immune
2
Replies
21
Views
2K
zappa
Z
Paul B
Earthworms as fish food
Replies
4
Views
1K
xLennie
xLennie
S
sick tank
Replies
7
Views
847
rolyguy7
rolyguy7
Back
Top