I was seeing this again today. Looked like a freshly molted shrimp and it was being torn apart. It was pale and didn't look like it had a hard shell. I've looked around the internet and I've seen people reporting such instances of cannibalistic neos. While it's not common, other people seem to have encountered this before. It maybe a lack of protein in their diet and they are looking for the next best source. I'm hoping the extra mulberry leaves and Hikari crab bites will help tone this back. Right now I drop in 3-4 crab bite pellets but I don't think that is enough to go around? I have no clue how much to feed without being considered over feeding.
I still have, or think I have, a healthy population, with lots of younger shrimp, from shrimplets to young adults. There are still some older adults around and some berried mamas but I no longer have my really big, massive shrimp I originally had. I'm going to guess that with the possibility of overcrowding and less access to quality food in general (with the population size), they aren't growing nearly as large. What still concerns me is that I do find shrimp that stand around and chill? They don't do a thing, just sit there, motionless. It's not in a specific corner, gathering or area, but just through the tank. I read some things online that shrimp do need to "sleep" but I don't know how true that is (there are not a lot of sources). I just remember that previously when I started the tank and the few months after, shrimp were constantly busy.
Edit: today I did see at least 2 shrimp being torn apart. I don't know if they were dead or dying. The other shrimp were really savage and acting like they haven't eaten in days, fighting over the corpse. I saw another shrimp dying, it was all pale and looked like it might have struggled to molt. It tried to jump, like they do when molting but couldn't. I did not see a white ring of death or anything though. It was just pale, weak, laying there and twitching. I don't know what happened to it. I doubt it was able to molt but I didn't see a dead body where it was last seen. Losing 3+ shrimp a day seems to be a real big problem.
Water testing still showed 0 ammonia, 0 nitrites and about 5 nitrates. GH 5 and KH 5. GH is a little lower than I want but I'll try to bring it up on the next water change this Saturday. PH was the odd one. Originally when I measured, it was 7.5 PH but I very recently cleaned my PH meter and recalibrated. Now it's showing around 7.8 PH which seems kind of oddly high. Though I have no clue what would be causing that to rise. IIRC, it was 7.8 in the morning and was also 7.8 late afternoon.