More unidentified critters

[VoodooChild]

Heyya folks. Alright, this is the last round. I promise. One unknown organism resides underneath one of the rocks. It has veeeery long white tentacles that just hang down and catch bits of stuff. Sometimes late at night these tentacles (well over 4" long) will kind've make a network at the bottom of the rock and go across the paths to other rocks. They do react to my touch. I was thinking some creepy anenome. The other things are tiny little brown guys on the glass. They have spikes like urchins but don't move. I thought diatoms were flat. I crushed one (I have several dozens) and it kind've exploded into a green splash. What are they? Do any of these things need to be removed and if so how? Thank you.

[OrionGirl]

There are several tantacled critters, so I can't really help out with that one. But, the other guys really could be a tiny urchin. We've had several hitch hike into the tank on LR, and they start out very small, mostly stationary. Then they hit a certain size and start cruising. They can be a pest--they tend to knock around and bump into things. We've never had problems, and just ignore them.

[VoodooChild]

Thanks Orion. You're a help as always. I wiped out most of the "urchins" last night. I left the biggest ones. When they start out do they have only one spike? Some almost look like they have branched spikes. I crushed one with my finger (stupid thing to do in hindsight) and it didn't jab into me. Nothing import, I just like to show people that come over what this and this is...:D