5 Sep 2016
I'm really puzzled!! (they were bought to help combat my BBA) Looking for your input

I recently purchased 20 Amano shrimp from Pro shrimp, after spending a 6/8hrs acclimating they entered my tank after lights out on Thurs 24th Oct, on Friday they were nowhere to be seen I wondered if they were in hiding I couldn't see and skeletons/carcasses so thought to my self I will explore tank closely on Sat during routine maintenance. After water removal, I thought this would be the perfect time to find the little blighters to my dismay I still could not find any until I moved 1 of the rocks touching the glass, there was only 5 behind it 5 out 20!
I started to question myself as to what the hell was happening if it was bad water then surely I would see the carcasses/skeletons but there was nothing.
I did have a large-ish Angel (approx 4 inches) in the tank at the time, I know they can and will eat anything they can get in their mouths but never had any issues with my first batch not that I saw anyway. I watched the tank very closely after getting home from work for the next week but never saw any of them even the 5 that I found hiding. I checked again during water change as above but no joy.
After this weeks water change, I decided to take a drastic step as there had been no evidence to say the water was bad it must have been the Angel but still find this very hard to believe 15 overnight and 20 in 3 days, blimey I thought it was an angel, not a flaming piranha. Anyway, I digress I took the angel to my lfs yesterday Sun 3 Nov and purchased another 15 shrimp and (and 9 new cardinals) in the hope they will do the job in hand. They were all acclimated over 5/6 hrs then put in the tank 1hr before lights out so I could see them and make sure they were not in any distress, they all swam off and were swimming around without any problems not drawing any attention from any of their tank mates.
Obviously not want to lose any more shrimp or money, I'm keeping an eye on the new batch and tonight I have only seen 4/5 a couple out in the open and a few semi hiding.


19 Feb 2018
I'd be checking there too. I pulled 4 and 3 cherries out of my oase biomaster earlier. Fortunately all were fine


24 Dec 2014
Most shrimp are fine inside filters as long as there is sufficient oxygen (ie, filter is not turned off for sufficient time)

An adult angel can certainly wipe out (& possibly consume) 20 shrimp in very little time ... though if these were mature female Amano’s I’d expect some hidden survivors
You don’t mention how long it’s been since the first batch of Amano shrimp (how did they disappear?) but adult angelfish are much more likely to notice and hunt down new additions to their territory (small fish, shrimp etc)

Re the BBA, I suspect you’ll need to eradicate the mature BBA, then hope for the new shrimp to stay on top of emerging BBA ... of course, this still depends on the Amano’s being sufficiently motivated
Once the BBA has been damaged (peroxide, Seachem Excel etc) shrimp and snails will often clear up the remains

Amano shrimp are excellent at hiding - I’ve often thought they were long gone, only to find them all :wideyed: when breaking down a tank - so hopefully yours are doing the same