How long do Peppermint shrimp live for?

[robbyville]

Hi all,

As some might remember, I had purchased a couple of peppermint shrimp about 6-7 months ago, thought they had been eaten, and then found one still alive a couple of months back. He had grown by at least 100% and every now and again I would see him chomping down.

Yesterday, we found him dead on the sand bed, definitely not an empty shell from molting.

We have been battling hair algae for a few weeks now, but otherwise all parameters seem in order.

I'm just wondering if this might simply be the life span for these shrimp, or how temperamental they are to fluctuating parameters, heat, etc (Although my heat stays between 78 and 82 deg).

Thanks for any thoughts!

Rob