Freshwater vs Saltwater Disease

WheatToast

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I keep thinking about why it seems as though freshwater fish diseases seem less-commonly talked about compared to saltwater fish diseases and was wondering if anyone else had any insights/thoughts.
My guesses on why this is were that:
a. Freshwater fish might be more disease resilient as they live in smaller bodies of water and might therefore face higher pathogen concentrations
b. The freshwater hobby is more widespread than the saltwater hobby and would proportionally host more inexperienced hobbyists and companies that target these inexperienced hobbyists that ignore/downplay/are vocal about fish disease
On a separate thread, @Sharkbait19 mentioned that:
c. Freshwater fish are usually cheaper than their saltwater counterparts
d. More freshwater fish are being captive-bred in disease-free environments compared to saltwater fish as opposed to originating in the wild
 

Sharkbait19

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Another thing I can mention is that fw disease often is easier to treat. There are still some really bad ones, but many can be treated simply with salt and heat (namely fw ich), and also can safely be treated in the tank (no coral and usually no inverts to worry about).
I’m sure @Jay Hemdal can talk better about it than I can though.
 

Jay Hemdal

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I keep thinking about why it seems as though freshwater fish diseases seem less-commonly talked about compared to saltwater fish diseases and was wondering if anyone else had any insights/thoughts.
My guesses on why this is were that:
a. Freshwater fish might be more disease resilient as they live in smaller bodies of water and might therefore face higher pathogen concentrations
b. The freshwater hobby is more widespread than the saltwater hobby and would proportionally host more inexperienced hobbyists and companies that target these inexperienced hobbyists that ignore/downplay/are vocal about fish disease
On a separate thread, @Sharkbait19 mentioned that:
c. Freshwater fish are usually cheaper than their saltwater counterparts
d. More freshwater fish are being captive-bred in disease-free environments compared to saltwater fish as opposed to originating in the wild
I think it is a variety of factors:

- many freshwater fish are hardier due to living in more variable conditions, as opposed to reef fish that live under constant conditions.

- the commonly sold freshwater fish are also inherently hardier (except a few like mollies).

- many more freshwater fish are captive raised, and that is always a benefit. Wild caught discus have tons of disease issues.

- many SE Asian marine fish are caught with cyanide and that presents a much higher mortality rate.

Jay
 

sheel be right

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Another thing I can mention is that fw disease often is easier to treat. There are still some really bad ones, but many can be treated simply with salt and heat (namely fw ich), and also can safely be treated in the tank (no coral and usually no inverts to worry about).
I’m sure @Jay Hemdal can talk better about it than I can though.
one up of this too i agree, in freshwater there are some diseases which are a pain such as columnaris which is a pain to deal with (just about as hard as velvet to deal with for a saltwater comparison) but id say saltwater fish can be much more resilient than freshwater fish in some cases as many freshwater fish have weak genetics due to selective breeding (such as flowerhorns and other hybrids).
 

Jay Hemdal

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Ionic pressure with medicine dissolved in water readily goes into a freshwater fish but is pumped out of a saltwater fish?
Actually, it’s the other way around - marine fish drink constantly, while freshwater fish need to excrete fluids to keep from drowning. That may mean though, that toxins in the water may be worse for marine fish since they are drinking all the time.

Now, nitrite and copper are more toxic to freshwater fish, but my understanding that’s because salt in the water renders it less toxic to marine fish.


Jay
 

KrisReef

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Actually, it’s the other way around - marine fish drink constantly, while freshwater fish need to excrete fluids to keep from drowning. That may mean though, that toxins in the water may be worse for marine fish since they are drinking all the time.

Now, nitrite and copper are more toxic to freshwater fish, but my understanding that’s because salt in the water renders it less toxic to marine fish.


Jay
That's why I let you do the talking, as I often get mixed up on the details. ;) :cool:
 

sheel be right

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Actually, it’s the other way around - marine fish drink constantly, while freshwater fish need to excrete fluids to keep from drowning. That may mean though, that toxins in the water may be worse for marine fish since they are drinking all the time.

Now, nitrite and copper are more toxic to freshwater fish, but my understanding that’s because salt in the water renders it less toxic to marine fish.


Jay
ive got a question totally unrelated jay,
in Australia many aquarium stores freely sell trichlorfon, ive always warned my customers about its dangers and ive personally only used it once without success
(only used it as metroplex and prazi can be very hard to get in Australia) do you think this medication should have a tighter restriction?
 

lion king

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I'll say this, I set up 2 freshwater planted tanks a little over a year ago, between the 2 got over 20 fish. Not one death, no disease, everyone is still alive. You couldn't even imagine that with saltwater. One thing is most, really maybe all, freshwater fish are captive bred.
 

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I keep thinking about why it seems as though freshwater fish diseases seem less-commonly talked about compared to saltwater fish diseases and was wondering if anyone else had any insights/thoughts.
My guesses on why this is were that:
a. Freshwater fish might be more disease resilient as they live in smaller bodies of water and might therefore face higher pathogen concentrations
b. The freshwater hobby is more widespread than the saltwater hobby and would proportionally host more inexperienced hobbyists and companies that target these inexperienced hobbyists that ignore/downplay/are vocal about fish disease
On a separate thread, @Sharkbait19 mentioned that:
c. Freshwater fish are usually cheaper than their saltwater counterparts
d. More freshwater fish are being captive-bred in disease-free environments compared to saltwater fish as opposed to originating in the wild
a. Doubt this
b. True
c. Not necessarily but true on average
d. Disagree - partially. If one agrees with this, then @Paul B 's theories would have less merit
 

EeyoreIsMySpiritAnimal

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- the commonly sold freshwater fish are also inherently hardier (except a few like mollies).
Wait -- I thought mollies were very hardy. What am I missing?
 

lion king

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Some are starting to do captive only tanks, if they get their fish direct from the captive source they have relatively no or very few issues. No disease and acclimation issues with no nutritional decline which also adds stress. From the collection practices, transport, and holding methods of marine this adds a tremendous amount of stress. These environments make prime environments for the spread of disease. The sudden nutritional decline lowers their immune systems, in the wild they are eating whole live organisms. There are very few wild collected fish in freshwater, and they tend to be discouraged and are unappealing to most. The systems are still overcrowded but the fish grew up in them, developing more resilience to that environment. They have been grown and are already eating the foods that a hobbyist will be feeding. I think the biggest difference is wild vs captive.
 

lion king

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PS - many people would suggest that Discus are as difficult or more difficult to care for than reef/saltwater fish. Edit (disagree)

Discus have very specific water conditions and are not as forgiving. Mollies come from some very shady sources today and are mass produced. Otherwise if you get them from a reputable source or breed your own and keep them in brackish water, they are very resilient. They are true brackish fish and will be more prone to disease if kept in full freshwater.
 

Jay Hemdal

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Wait -- I thought mollies were very hardy. What am I missing?

In freshwater tanks, mollies are actually pretty delicate. They do best with some salt in their water, and then, people usually don't feed them enough plant material in their diet. They are also prone to FW ich if no salt in the water. So - they are hardy, but not if you don't meet their needs, and very often, people don't.

Jay
 

EeyoreIsMySpiritAnimal

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In freshwater tanks, mollies are actually pretty delicate. They do best with some salt in their water, and then, people usually don't feed them enough plant material in their diet. They are also prone to FW ich if no salt in the water. So - they are hardy, but not if you don't meet their needs, and very often, people don't.

Jay
Thanks!
 

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Mollies in general are extremely hardy and they are only fragile in soft water. Others like the balloon mollies are mass bred deformed (scoliosis) fish that you shouldn't expect to live.

Only P. lapatinna is a brackish water fish, P.sphenops and P. velifera (my favorite) are both freshwater species. If you keep a lapatinna in brackish water and regularly change the salinity up and down, the fish is practically bullet proof. I never had to deal with diseases in my brackish tanks, since relatively (key word) few bacteria and parasites survived the transition from freshwater to salt and back again (including nitrosomanas, Archaea are more resilient).

I have largely abandoned posting on forums (just read) but I used to respond to 50+ a day on the disease forums of Fishlore and still didn't cover it. I would disagree that saltwater is seeing more disease than freshwater. I would also point out that several of the medicines (antibiotics) are ineffectual in high PHs and others like Malachite Green (prominent anti-parasitic in freshwater) is extremely toxic at high PH levels.

40+ years Freshwater, NPTs, Hillstream, and brackish tanks
I look forward to building my monster saltwater tank (wall of my bar) in the near future, if my house ever gets finish being built.

I am going back into hiding.
 

KrisReef

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Mollies in general are extremely hardy and they are only fragile in soft water. Others like the balloon mollies are mass bred deformed (scoliosis) fish that you shouldn't expect to live.

Only P. lapatinna is a brackish water fish, P.sphenops and P. velifera (my favorite) are both freshwater species. If you keep a lapatinna in brackish water and regularly change the salinity up and down, the fish is practically bullet proof. I never had to deal with diseases in my brackish tanks, since relatively (key word) few bacteria and parasites survived the transition from freshwater to salt and back again (including nitrosomanas, Archaea are more resilient).

I have largely abandoned posting on forums (just read) but I used to respond to 50+ a day on the disease forums of Fishlore and still didn't cover it. I would disagree that saltwater is seeing more disease than freshwater. I would also point out that several of the medicines (antibiotics) are ineffectual in high PHs and others like Malachite Green (prominent anti-parasitic in freshwater) is extremely toxic at high PH levels.

40+ years Freshwater, NPTs, Hillstream, and brackish tanks
I look forward to building my monster saltwater tank (wall of my bar) in the near future, if my house ever gets finish being built.

I am going back into hiding.
Is the bar operational or are you on the wagon until the construction is completed?
 

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