Did my plecos eat my shrimp?

A couple weeks ago, I added four red cherry shrimp to my L199 tank. Lots of people on the ZebraPleco forums have seemingly kept cherry shrimp in Hypancistrus breeding tanks, and I've never had shrimp but always fancied some. The only other fish in the tank are pygmy corys and three otos. On paper, it looks ideal.

I have not seen a single cherry shrimp for about five days now. As you can see from the pic (taken side-on... it's a 3' tank), there are plenty of places for them to hide.

On the other hand, Hypancistrus species are meant to be shy, nervous feeders, but mine aren't. I don't know if they would go after a live shrimp, but I would not put it past them. I don't know if I should get more cherry shrimp because they would do better and be more active in larger numbers, or if I am just giving the plecos expensive shrimp cocktails.

Its plausible theyre hiding, ive heard with other fish they can be extremely shy

Most likely hiding... Plecos do not eat live fish/invertebrates, only dead ones.

My cherry shrimp hide very well in my 29g, it’s common.

If I wanted more, I would safe enough to get them? I didn't intend on only having four. The LFS was in short supply, and it's all they had. The wee shrimp must be popular.

Did you say it’s a 3ft tank?

Yes.

Then yes, there is plenty of room for more cherry shrimp.

Cool. Only other concern I have are the powerheads. Are they stupid enough to crawl through the slats on the sides of the powerheads? If they've done that, the plecos will have had diced shrimp.