Water Changes Increase Social Aggression (Study on FW Angelfish)

[Dancingmad]

Howdy Fellow reefers - I found this article referencing a recent study, and thought I would share it to open up some wild speculation and anecdotal experience sharing.

Seems like the assertion is that water changes makes angelfish grouchy and sort of resets their hierarchy due to changes in the chemistry of the water. That's oversimplifying but check out the articles. What say y'all community?

I'll have to pay attention to my chromis and see if they get grouchy with one another after a WC.

http://www.sciencemag.org/news/2018...ing-angry-try-changing-their-water-less-often

http://www.appliedanimalbehaviour.com/article/S0168-1591(17)30288-5/fulltext

 

[pandagobyguy]

Howdy Fellow reefers - I found this article referencing a recent study, and thought I would share it to open up some wild speculation and anecdotal experience sharing.

Seems like the assertion is that water changes makes angelfish grouchy and sort of resets their hierarchy due to changes in the chemistry of the water. That's oversimplifying but check out the articles. What say y'all community?

I'll have to pay attention to my chromis and see if they get grouchy with one another after a WC.

http://www.sciencemag.org/news/2018...ing-angry-try-changing-their-water-less-often

http://www.appliedanimalbehaviour.com/article/S0168-1591(17)30288-5/fulltext

I personally notice more aggression in my clowns post maintanence. I have always assumed this was just from the intrusion of a pair of hands flying around their house though.

 

[Randy Holmes-Farley Verified Community Expert]

Interesting.

As a chemist, I'll comment that the work is clearly being done by people who focus on behavior and not the chemistry of what might be happening. While they talk about chemicals released to the water by the fish:

"Many fish species use chemicals released into the water as cues for communicating social status."

There's no mention or discussion of whether the "clean" water they are using might actually be irritating the fish. How do they prepare it? Is it exactly the same salinity? Temp? Chlorine?

They test and control some things ( control temp in the tank, along with O2, but do not measure ammonia and nitrite until the "end" of the experiment).

How can you not clarify how the clean water is prepared??? Tap water? DI?

 

[Dancingmad]

There's no mention or discussion of whether the "clean" water they are using might actually be irritating the fish. How do they prepare it? Is it exactly the same salinity? Temp? Chlorine?

They test and control some things ( control temp in the tank, along with O2, but do not measure ammonia and nitrite until the "end" of the experiment).

How can you not clarify how the clean water is prepared??? Tap water? DI?

I agree - that is one of the things I find frustrating about studies published on the web now. That goes for pretty much all those pop science studies out there now.

 

[Gareth elliott]

Its not just pop studies, a vast majority of studies are either never peer reviewed or when they are can not be replicated. Not passing judgment, it would be impossible for every study to be.

This particular study also doesn’t address the breeding cycle of amazon or orinoco fish that is often cued by the rainy season. And the fact that in the wild these fish are found in pairs not hierarchies. Does the cue of the breeding season in an unnatural population have any role in the findings?

 

[MnFish1]

Well is it not well known in freshwater fish especially cichlids that 'rain'/'fresh water' stimulates breeding behaviour which would lead to aggression?

 

[Gareth elliott]

Well is it not well known in freshwater fish especially cichlids that 'rain'/'fresh water' stimulates breeding behaviour which would lead to aggression?

Was more a follow up to randys questions.

Knowing that “rain” triggers breeding behavior, wouldnt a control be gh?

Or instead after these findings complete a study by adding or removing chemicals thought to be pheromones involved? The aggression version of Schreckstoff lol. Seems like it was published before it was fully thought out is all i was trying to say

 

[MnFish1]

Was more a follow up to randys questions.

Knowing that “rain” triggers breeding behavior, wouldnt a control be gh?

Or instead after these findings complete a study by adding or removing chemicals thought to be pheromones involved? The aggression version of Schreckstoff lol. Seems like it was published before it was fully thought out is all i was trying to say

Yes - I agree with you - the problem is you can only read the abstract, not the discussion (unless you want to pay for the article - which I did not). My guess is that they discussed some of these issues before they wrote their conclusion (hopefully).

 

[TerraFerma]

Howdy Fellow reefers - I found this article referencing a recent study, and thought I would share it to open up some wild speculation and anecdotal experience sharing.

Seems like the assertion is that water changes makes angelfish grouchy and sort of resets their hierarchy due to changes in the chemistry of the water. That's oversimplifying but check out the articles. What say y'all community?

I'll have to pay attention to my chromis and see if they get grouchy with one another after a WC.

http://www.sciencemag.org/news/2018...ing-angry-try-changing-their-water-less-often

http://www.appliedanimalbehaviour.com/article/S0168-1591(17)30288-5/fulltext

Improved water quality after a large water change usually gets FW fish in spawning mode. That would explain the post water change aggression.

 

[Randy Holmes-Farley Verified Community Expert]

Yes - I agree with you - the problem is you can only read the abstract, not the discussion (unless you want to pay for the article - which I did not). My guess is that they discussed some of these issues before they wrote their conclusion (hopefully).

pm sent

 

[erk]

My personal experience hasn't been much aggression, but more signs of breeding/spawning. In my saltwater tank, I notice the inverts tend to spawn right after a water change. Primarily my urchins. The only spawning fish I have seem to get more active and chase the female a bit more, but that's about it. In my freshwater tanks I kept in the past, I also noticed an increased drive to spawn following a water change. This might cause increased aggression. Based on some quick research at the time, I found that the water change seemed to simulate a raining period and many fish tend to time their spawning with rain. Can't say definitively why, but I speculate that it is because rain indicates increased resources for the offspring and can also carry the offspring down stream. The fish this was most apparent with was my pair of Pelvicachromis pulcher aka Kribensis cichlids. They almost always bred right after a water change.

Edit: I forgot to state, I did water changes for my freshwater cichlids with well water from N. Florida.