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Cherry Shrimp Dying

Vinkenoog1977

Member
Joined
14 Apr 2014
Messages
560
Location
The Hague, Netherlands
Hey guys,

For the last couple of weeks, my red cherries are/ were dying one by one. They all had a crack in their shell, right behind the head, such as in this picture:
attachment.php?attachmentid=95948&d=1337633255.jpg

After a bit of research, I found that harder water (which I have here; dH ~11+, 2 mmol/l (Ca2 + Mg2)) in combination with higher temperatures, cause excellerated growth, whilst hardening the shells, causing molting problems. Well, I had raised the temperature to 25-26 C while I had a nice Betta as a house guest. So, about 16 days ago, he left for home, and I gradually brought the temperature back down to 21-22 C. I am however still finding dead shrimp, recently deceased, so I'm now getting a bit anxious that I might have gotten the cause wrong. Due to that, I have now also stopped ALL feeding for the coming 10 days.

My question is now: are the dead shrimp I'm finding now, still related to the higher temp period, or could there be a different cause?

The tank in question is Opium Cartel (link in signature).

Thanks in advance for any help you might be able to give me.
 
Neither the temperature, nor your water should be the cause of the deaths. Mine are too in harder water than yours and I've kept them in anything from 20C to 30C successfully.
But the molting problems are normally lack of calcium which is strange considering your water stats.

I would search for a different cause than the water being hard, or the temperature. Check for ammonia/nitrite spikes, any other possible chemicals that come via your water change, any sort of fluctuations, etc.. And although the water is hard, the calcium ion can be used up by other processes and become unavailable to inhabitants although the Gh test for total ions so a high reading doesn't mean available reading and if not enough and big enough water changes are done, it can get depleted.

Here are some of mine. Temperature for the last 2 years 25-26C, Gh 12-13
RedCarpet_zpsqtx9ndft.jpg
 
Thanks for your reply!

I checked my water parameters with a testkit, and found nothing out of the ordinary, other than water hardness going close to the red line. I treat my water with Seachem Prime before WC.
The oddest thing is, it only seems to affect my red cherries, there are about 2 dozen yellows in there, as well as some blues, and they appear unaffected. I've also had quite a few babies appear the last couple of weeks. I did however notice, in hindsight, that during the higher temperature period, that I found no molts in the tank, which have been starting to appear again the last week.

P.S.: I also have quite a few different snails in there, and they have no issues either. So that should rule out calcium deficiency and copper poisoning.

P.P.S.: It's mostly the larger ones that are dying, only found one smaller dead one so far. And I have found more large (XL) shrimp dead in the tank, than I put in there.
 
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They all have different mechanisms for taking up calcium so I wouldn't use the snails as a measure. On the yellow shrimp you might not be able to see the "crack".
As for molts, I rarely see them because they get eaten immediately but I have lots of hungry shrimp.
It could have been a sudden poisoning of something that went away but the old weaker ones got affected.
I am only speculating because thankfully I haven't dealt with shrimp diseases.
The only time I got some is when I accidentally dropped the temperature several degrees via a cold water change and even then not many died, just a few.

If I were you, I'd just keep doing water changes and see if it resolves itself in time.

Also, if it's the large ones only, how old are they? They are bound to die at some stage. Normally shrimp are cannibals and eat the dead ones but if you don't have enough shrimp to do that, you'll see the dead ones.
The ones you bought may be all the same age and sort of dying at about the same period of time.....
 
Maybe well off the mark but could the betta be to blame? I know from experience my betta would actively hunt down shrimp. They would catch and if possible kill but rarely eat as they were too big to fit in it's mouth. Betta are quite good at fitting into little gaps where shrimp would try and evade.Perhaps the betta had been having a go at them but not quite got enough of a grip damaging the shell and they succumb to a secondary infection.

That wouldn't explain the yellow ones not being affected though other than possibly they have but the colour contrast doesn't stand out as much or maybe the betta saw the yellow colouration as poisonous and didn't fancy them.

I had a female betta that would squeeze between hard scape and pull RCS out by their tails. Shame really as when it had killed it it seemed to get bored and just leave it floating about. I think it was a case of the hunt being better than the kill.
 
If the shrimp had been trying to evade capture by crawling head first into some small gap and the Betta had been tugging on it from the tail that might explain the splitting of the shell just after the main body like it shows in your pic. I would wait and see if this fades, IME, if your tank had been fine for a while then sudden problems go back to the last thing you did different which in your case was introduce the Betta.
 
I hope it works out for you :) In my case I decided not to remove the Betta. Not fair on the RCS I know but I have a constant supply from my shrimp only tank. The betta doesn't get them all as there is still a number of shrimp knocking about albeit very rarely seen. The betta doesn't have that long a life span IME so I'll let it live its course. I won't be trying to mix the species again. I put a a cattapa log in the tank with a stone at the front and back entrance opening this would provide a safe place only the shrimp would fit in but the Betta seems to move stuff about and the gravel to gain access. :(
You can't take the instinct to chase and hunt prey out of the fish I'm afraid. I was lulled into a false sense of security in my local LFS which had betta and RCS in the same tank with very little cover other than a piece of wood with a java plant growing on and bare bottom. He said he had no problem with them but I suspect in the shop environment where the betta also felt threatened that survival mode kicked in and it was busy with self preservation. Once home with plenty of cover it had more time to hunt.
 
Hmm, makes you wonder if it might be down to whether they are raised around shrimp or not. Some say if the shrimp are there first they are less likely to get ate. Adding them afterwards can be seen as an addition of food for the existing fish. Once they have a taste for them :twisted:
 
I think they're intelligent predators and have individual personalities. I had a similar experience with Sparkling Gourami, another anabantid which are sympatric with some Betta spp.... http://www.seriouslyfish.com/species/trichopsis-pumila/ scroll to the comments at the bottom of the page, they're quite interesting.
 
It's so odd, since my own two Bettas never even looked at them, they are chill as can be, but this one was quite dominant from the get go. I did keep a good eye on him, and only ever saw one shrimp, in two bits, fly past, but who knows how many he damaged in the process. Will still keep them on a "fast" for the next couple of days, might have been overfeeding them a bit.
Speaking of which, during the Betta's stay, I fed him serveral times a day, in hopes of keeping him of the shrimp. The overfeeding might have started there, did see some planaria after 3 or 4 weeks.
 
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