Osmotic Shock Delay

[bhav_88]

Just a quick question for someone with shrimp experience. If a shrimp is suffering from osmotic shock, how long can said shrimp be expected to remain alive before it dies?
I ask because I recently got some cleanup inverts, complete with some shrimp. Though I drip acclimated over a period of 3 hours, I am not certain the water level increased enough because I'd never drip acclimated before. (Neglected to mark the bucket so I'm not sure if it doubled, quadrupled, or what)
Most of the shrimp began acting comatose; it took two days for the CBS to die, and three for most of the peppermints. By day three, the peppermints that weren't comatose initially were acting it and died days later. All crabs and snails are fine.
My thought is that since osmotic shock causes cells to rupture/shrivel, it would kill fairly quickly. But I've tested everything I can think of and all of it is within a healthy range, so my only thought was that I messed up acclimating.
Could a shrimp survive several days while the shock killed it?

 

[ophiura]

I would say so, yes. Seastars, for example, can die of osmotic shock within a month of introduction (or major sudden change in tank parameters).
Out of interest, do you have other inverts in the tank?
What is your specific gravity?

 

[bhav_88]

SG is 1.023, and yes, I have crabs and snails. There's even some species of snail (nassarius, maybe?) that's reproducing like mad, covering my glass with these tiny white snails when the lights go out.
Somewhat of a relief to know that such a delayed death is possible... At least now I have a possible culprit.

 

[ophiura]

IMO, and it could be an issue, your specific gravity is on the low side for many invertebrates. 1.025-1.026 is ideal...do you measure with a refractometer or hydrometer?

 

[bhav_88]

Hmm... perhaps I ought raise the salinity a bit, then.
Since I'm a poor college student and can't afford a refractometer, I use two hydrometers and make sure they always agree.

 

[ophiura]

One of the things you may want to look into, is asking your LFS what the specific gravity is at their store. If it is significantly low, for example an invert system at 1.021 or so, then I would avoid them. The animals will already be stressed. I would in general buy invertebrates from systems kept at higher specific gravity.

 

[anonome]

This is very true, when I buy online...I test the water for salinity when it arrives, then acclimate accordingly.

 

[fbm]

You should IMO check the water you get them in and yours everytime you acclimate something. See how far off they are and acclimate until they are withing .001 of each other. I have never had anytroulbe with anything acclimating this way.
Some people say 3 hours some say 1 hour but I just go off of what the water reads. I also check ph as well but seems to me my ph has never been off.
Also I don't drip because I don't have a setup, or even a air line tube. So what I do is I add a 1/4 to a cup of water every 15 minutes until I get the right readings.

 

[bhav_88]

Well, I'll definitely try that this summer when I get some money... I love shrimp but have never been able to keep them. I wasn't aware invertebrates needed a higher salinity, so I'll also work on raising that a bit.

 

[hatessushi]

I always drip acclimate to what my tank water is. If I received something with the SG way off it makes it take that much longer. I do the same thing with Ph and temp. My last fish came in water that was 67 degrees, since I had to acclimate to my 78.5 degrees the SG matched withing about 2 hours but the temp took 6 hours.

 

[ninjamini]

Originally Posted by ophiura
One of the things you may want to look into, is asking your LFS what the specific gravity is at their store. If it is significantly low, for example an invert system at 1.021 or so, then I would avoid them. The animals will already be stressed. I would in general buy invertebrates from systems kept at higher specific gravity.
Ya know I never thought of that. Thats a great idea. I would say that I would think to bring my hydrometer to the store and ask if I can measure.

Great idea.

 

[bhav_88]

UPDATE: It seems I was very slightly fast in condemning all my shrimp to death. Though I hadn't seen him in a week, I discovered a single peppermint shrimp survived where all others died. This sounds like it's got to be shock, I'll be a lot more careful next time.