I lost a couple!

So heres something weird. This morning I noticed a couple little pellets of leftover food and they had this fuzzy halo shaped thing growing on them. Never seen this in any of my tanks, any ideas? Is it possible this is also killing the rcs?

This sounds like a fungal growth.
I've seen something similar on leftover food.
No ill effects in my tank, though leftovers should be removed as a rule.
 
Shrimp also need well established tanks so if this is a new setup that may explain things a bit. Some sites recomend not adding shrimp until a tank has been running for 6 months at least. Not sure if this is true or not though.
 
Interesting points mellow. I will split up my stock and see what happens. Some things I have noticed about my tank:

1) Shrimp die slowly. They appear healthy as far as colors go, but they lie on their sides on the substrate and can only move some of their legs. They can flick their tails a bit, but that is all. My assassins won't eat them.

2) MOst of the dead seem to be females, mostly "middle-aged." Some were berried, some jsut had babies.

3) I did not notice deaths till approx. 2 weeks ago. My population has exploded, and I appear to have more MTS in the tank as well. possible competition...

4) Pesticide was definitely used within that time period. No ill effects in any of the other tanks, but this is the only tank with shrimp(and its an older tank, 2yrs).

5) I have not dosed iodine for awhile.... That is the only change in water so far(my water will switch from surface to well water for a month in November).
 
Tank is well over a year old and has housed everything from red claw crabs to red parrots with no trouble at all. I think rcs just arent for me. Maybe ill just go the crab route again
 
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