hitchhiker

Hello, new to the forum here, and hopefully am doing this right! Late last night I spotted this little guy on the back of the tank, not moving. I've scoured the internet searching for answers, but I haven't come across anything that looks quite like it. It's about a half inch long, and...

I've had my tank up for about 2 weeks now and I'm just now starting to see hitchhikers from the LR.. Can anyone tell me what exactly that is under the rock? It looks like a starfish to me but I have no idea? It was sitting on top of the rock last night..