Ich prophylactic treatment in QT for Chromis Virids - temperature, or tank transfer?

Discussion in 'Fish Disease Treatment and Diagnosis' started by PeterDolan, Aug 13, 2017.

  1. PeterDolan

    PeterDolan Member

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    Hello all,

    I recently read two interesting things:
    * in FISH DISEASE - Diagnosis and Treatment, it's noted that Ich cannot complete its lifecycle at temperatures greater than 30*C / 86*F. The lifecycle is completed in 3-7 days at 25*C (and completes more quickly at higher temperatures), so I believe keeping the tank at 31*C for 7 days would effectively eliminate Ich.
    * in a recent article titled "Adapt, move or die – how will tropical coral reef fishes cope with ocean warming?" (http://onlinelibrary.wiley.com/doi/10.1111/gcb.13488/abstract), it's noted that Chromis Virids preferred to move from 31*C to 29*C temperatures, but was able to tolerate 31*C temperatures.

    I wasn't able to get any clear information on mortality rates at these higher temperatures, other than a suggestion that they can tolerate it but preferentially move to lower temperature water.

    So here's an interesting question: would it be effective to prophylactically treat Chromis Virids for Ich on intake in a quarantine tank by gradually raising the temperature to 31*C, holding it for a week, then gradually lowering it to their normal temperature of 26*C? Obviously this would require both a calibrated thermometer and a fairly accurate temperature controller with good circulation. Obviously also one would need to consider research on temperature tolerance for other species before applying this approach.

    And most importantly, would this be more or less stressful to the fish than the tank transfer method?

    How would this affect the cycling of the quarantine tank? Would it be possible to set up a fully cycled quarantine tank, and avoid medications that would interrupt the cycle?

    Thanks!
    Peter
     

  2. Big G

    Big G Well-Known Member Build Thread Contributor

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    My first thought was that as the temperature increases, dissolved oxygen in the water decreases. At 86 degrees that "could" cause other problems for the fish.
     
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  3. PeterDolan

    PeterDolan Member

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    Yes, agreed. From the FISH DISEASE book's section on dissolved oxygen and hypoxia, it looks like the difference between 29*C and 31*C is on the order of 7.84 mg/L -> 7.56 mg/L for fresh water, and a similar difference but lower absolute values (6.40 mg/L -> 6.19 mg/L) for very saline water.

    It also notes that "When the temperature is near a species' upper lethal limit, it is often wise to reduce or stop feeding, since the amount of oxygen needed for both homeostasis and digestion of food may exceed the amount of oxygen that can be extracted from the water (Stevenson 1987)". (the citation is of Stevenson JP's 1987 Trout Farming Manual)

    So, this approach would definitely require strong aeration (definitely an airstone, if not an oxygen tank) and particularly carefully monitored feeding.
     
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  4. 4FordFamily

    4FordFamily Tang, Angel, & Wrasse Addict R2R Supporter R2R Excellence Award Reef Squad Leader Build Thread Contributor Article Contributor Partner Member 2018

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    You're confusing freshwater ich with marine ich. Marine ich is not proven to be impacted marginally by temperature (at least not within the narrow band that our inhabitants can survive within). To that end, this will not work, unfortunately.

    I sure do wish I was wrong!
     
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  5. Big G

    Big G Well-Known Member Build Thread Contributor

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    Lots of other internal and external diseases start to pop up when water gets too warm for fish. And the longer they are exposed water temps near the upper tolerance levels, the rate of fatality increases noticeably.
     
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  6. PeterDolan

    PeterDolan Member

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    Oh, quite right! My mistake. In fact, reading the immediately-following section on MARINE Ich, it notes that they have optimal reproduction at 30*C!

    Wow, yeah, this would be the exact opposite of treatment for marine fish. It would be stressful to the fish, and heaven for the Ich.
     
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  7. 4FordFamily

    4FordFamily Tang, Angel, & Wrasse Addict R2R Supporter R2R Excellence Award Reef Squad Leader Build Thread Contributor Article Contributor Partner Member 2018

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    It happens. You're not the first to mix the two up! Very common misconception! :)
     
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  8. Humblefish

    Humblefish Dr. Fish Staff Member Team R2R R2R Supporter R2R Excellence Award Expert Contributor Article Contributor Louisiana Reef Club Partner Member 2018

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    Whether or not higher temp speeds up Cryptocaryon irritans life cycle is still considered highly speculative. It has always been assumed that it does, but never proven like with Freshwater Ich (Ichthyophthirius multifiliis). Meaning, no directed study has ever focused on that aspect (for some reason.)

    What has been proven is that 40C (104F) for 1 hour will disinfect a tank of Crypto by killing all tomonts & theronts. However, IMO no fish (or corals/inverts) could survive 104 F for 1 hour even if the temperature was raised gradually. In fact, I would argue all nitrifying bacteria in the rock would likely die as well - effectively "uncycling" the aquarium. o_O

    Source: http://edis.ifas.ufl.edu/fa164
     
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  9. aykwm

    aykwm Research Addict! R2R Supporter Build Thread Contributor

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    Thanks for sharing the articles. As well as whats mentioned above, i believe in case there is infestation you want to increase the life cycle of the parasite rather than decreasing it. Increasing the speed of the life cycle will overwhelm the fish and most likely kill the fish before it has a chance to fight it or develop immunity. I know this is the case for velvet, where fish has higher survivability rate when hit with the 72 hour strain rather than 12 or 24 hours.

    As mentioned earlier its not proven that crypto is affected with tempereture, but even if it is I dont think its good idea to do so.

    Best of luck
     
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