Fallow period for unknown killer

[davidcalgary29]

I seem to have lost the last fish in my Reefer 350 overnight -- a juvenile niger trigger, which has now disappeared. I didn't have many fish in the tank, but only managed to save one (a goby), which was slow enough to be caught in a net. It's now glaring at me in quarantine with copper, and eating well, so it seems likely it'll pull through.

I have no idea what took out the fish. There were no symptoms aside from the fact that the trigger sought out the cleaning shrimp frequently for the past week; no spots, colour fading, skin sloughing or really, anything were present on any of the fish. All fish fed well right up to their deaths; I found two partial corpses, but they'd been recycled by the CUC so necropsies were out of the question.

Question: would a 72 day fallow period cover all known diseases? It seems likely that this wasn't ich, unless there's a type that manifests only in the gills. And none of the fish were swimming into the power heads, so that would seem to rule out velvet.

 

[lapin]

WIthout knowing the cause of the deaths 72 days might or might not work.

 

[davidcalgary29]

Well, yes, of course. I suppose my question is: "are there any known diseases of marine fish which require a fallow period greater than 72 days"?

 

[Jay Hemdal]

Well, yes, of course. I suppose my question is: "are there any known diseases of marine fish which require a fallow period greater than 72 days"?

The 76 day period is from one study of ich tomonts in a xeric culture (bacteria free). The author later stated that this period would be shorter in real life applications. Neonendenia eggs hatch within 35 days. Amyloodinium tomont times aren’t known for sure, but are presumed to be less than ich. Therefore, 76 days is the maximum time that needs to be used. I started a post at the top of this section that discusses the option of 45 days.
Fallow periods fail for two main reasons; parasite propagules are added during the fallow period by transfer with invertebrates or cross contamination. Or - the disease organism isn’t an obligate parasite, and can live in the absence of a fish host; Uronema and bacteria.
Jay

 

[davidcalgary29]

The 76 day period is from one study of ich tomonts in a xeric culture (bacteria free). The author later stated that this period would be shorter in real life applications. Neonendenia eggs hatch within 35 days. Amyloodinium tomont times aren’t known for sure, but are presumed to be less than ich. Therefore, 76 days is the maximum time that needs to be used. I started a post at the top of this section that discusses the option of 45 days.
Fallow periods fail for two main reasons; parasite propagules are added during the fallow period by transfer with invertebrates or cross contamination. Or - the disease organism isn’t an obligate parasite, and can live in the absence of a fish host; Uronema and bacteria.
Jay

Do you think that this was velvet? I tried to upload a video, but it didn't work. Breathing was extremely rapid as this fish was moribund. It didn't swim into the powerhead and wasn't terribly light shy. Those...flaky patches arose about an hour before the fish died. The fish was put into therapeutic (copper) quarantine at 2.0 (strength attained over the course of a day) ppm after I broke down my tank and finally caught it. The lone survivor, a goby, was caught days earlier as it was pretty lethargic, and survives in the hospital tank.

 

[Jay Hemdal]

Do you think that this was velvet? I tried to upload a video, but it didn't work. Breathing was extremely rapid as this fish was moribund. It didn't swim into the powerhead and wasn't terribly light shy. Those...flaky patches arose about an hour before the fish died. The fish was put into therapeutic (copper) quarantine at 2.0 (strength attained over the course of a day) ppm after I broke down my tank and finally caught it. The lone survivor, a goby, was caught days earlier as it was pretty lethargic, and survives in the hospital tank.

Sorry, I can’t say based on that photo. Velvet is a lot rarer than ich, and in moderate to advanced cases of ich, you may not see discrete spots. I always use a microscope to ID protozoan infections….visual symptoms overlap so much.
Jay