What are all the reasons shrimp become inactive?

[beanbag]

Hello folks,

I have a problem with shrimp being inactive.  Maybe it would be useful to have a thread where we can just start listing all the reasons so that it can be a checklist for others.  I assume that healthy and happy shrimp are active almost all the time, 24 hrs? 

In my case, it seems to be a sporadic problem.  That's the frustrating part.  Sometimes everybody is inactive.  Sometimes only one shrimp stays frozen in a spot for several hours while everybody else is moving around.  Then the next day that shrimp will be "back to normal".  In the 3 months that I've been keeping shrimp, I've only had two (both red cherries) where after about a month, they slow down, stop eating, and then die.  (And I don't know the reason because everybody else was fine)

The first to check are water parameters such as: pH, GH, KH, temperature, Ammonia, Nitrite, Nitrate, TDS.  All of mine seem to be within normal range.  Anything else to check?

How about food-related?  Can it be due to over feeding or underfeeding (i.e. not enough biofilm left)?  Or is it possible some of the shrimp develop a habit where instead of exploring, they just wait for food to arrive?

Molting?  Sometimes my shrimp will be inactive the day before and after a molt.

24 hr cycle?  I tend to turn on my light around 6 pm and the shrimp seem most active around 4-5am.  (I don't have the light on a timer yet)

Something to do with tank setup?  (The only thing out of the ordinary is that I am using an active substrate, Seachem Aquasolum, which has been out on the market for a few years now, but doesn't seem too common among the shrimp community)

 

[jayc]

I find the wrong water parameters for the type of shrimp to be a big factor for lethargic shrimp. It's usually the first sign that something is not right.

Any measurable amount of Ammonia, can also cause this behaviour. 

Moulting is also a big factor in shrimps being inactive. Right before and right after the moult they hide and usually don't move. The moulting process is very strenuous on the shrimp, and I find protein rich foods (eg bloodworms) helps a ton.

 

 

[nicpapa]

16 hours ago, jayc said:

I find the wrong water parameters for the type of shrimp to be a big factor for lethargic shrimp. It's usually the first sign that something is not right.

Any measurable amount of Ammonia, can also cause this behaviour. 

Moulting is also a big factor in shrimps being inactive. Right before and right after the moult they hide and usually don't move. The moulting process is very strenuous on the shrimp, and I find protein rich foods (eg bloodworms) helps a ton.

 

 

Also No3 , low Temp , and bacteria infections.

[jayc]

5 hours ago, nicpapa said:

Also No3 , low Temp , and bacteria infections.

Yes of course!

Forgot about high Nitrates, and of course illness.

But we probably need to clarify "low temps" for anyone new to the hobby.

Winter months can see water temps fall below the shrimp's preferred temp range. It might not be detrimental to their health but it does slow their metabolism down. The remedy for low temps isn't to just give them high temps either, it needs to be within their ideal preferred range for that specific shrimp, eg Neo Caridina or Caridina or Sulawesi.

I have known some people to have shrimp (cherries) survive our Australian winter out in ponds. So they can tolerate fairly low temps for an extended period.  

[beanbag]

Thanks for the pointers.

My parameters are GH6 KH 1, pH 6.6-6.8, 21-22C Ammonia 0 Nitrite 0 Nitrate <5ppm.  So those all look reasonable for CRS and cherry, right?

Regarding the ammonia issue, my tank always reads zero with the liquid test kit (due to biological filter).  However, my RO system generates a tiny amount due to the breaking of chloramine.  Maybe 0.1ppm or less total ammonia.  However, at a pH of below 7, nearly all of it is in the NH4+ form, so that should be ok, right?

As for bloodworms, I am kind of wary of them.  I fed it once, and only two of my shrimp ate them and then a week later one of them died.  Maybe it was for other reasons, but I also had problems trying to clean them up and spoiling the water.  Is there some other high protein non-water spoiling grazing food?

I installed a ramp timer, so that should take care of the lighting cycle.

I still think there is something food-related.  The other day, my CRS and one of the Amanos was just standing around being inert.  Then I dosed Bacter AE, and they all started picking at the substrate at full speed.

[jayc]

12 hours ago, beanbag said:

So those all look reasonable for CRS and cherry, right?

Yes those parameters look reasonable. pH is on the upper limits for CRS, however.

 

12 hours ago, beanbag said:

Is there some other high protein non-water spoiling grazing food?

I only know of three commercial products ... Lowkeys B18 protein, SL-Aqua More Meat

and Dennerle Shrimp King Protein. 

Alternatively, any fish meat. Or Freeze dried blackworms.

BTW, with regards to frozen bloodworms, maybe your batch is no longer fresh or too much was fed. Don't drop a whole cube in, only enough for each shrimp to get one bloodworm.  There should be no excess. I would use plant tweezers to feed each shrimp one bloodworm. But I admit, that can be a lot of work. So drop into the tank only as many bloodworms as you have shrimps and no more than once a week.

 

What RO system do you use?

Mine never shows any ammonia. 

<edit>- i'd better check the water from my RO before proclaiming that 

Edited November 29, 2018 by jayc