It was me - I had the baby briareus(I put 6 day-old hatchlings into my tank) and didn't know that one had survived until the crabs started disappearing - actually, first I saw the amphipods begin to disappear, then the crabs - but I never saw her until she was 4 months old! She came out in an angry red huff because my husband was scraping some algae off the glass. What a surprise!!
So you never know - you can always hope that one survives.