Sm shrimp or copepod?

So Its funny in the collection cup I see this think that is bigger then a copepod but looked like a shrimp. I saw it swimming and because of the gunk in it cant get a pic. I have tried for an hr to get a pic but cant get one. Is there an id site that might show some of these critters. I havent seen anything like it. I havent seen a pod in this tank yest but was supprised to see this thing. It looked like a shrimp is the only way to describe it. It was bigger then a pod. I have seen pods before def not that small but it was very small. Any thought? I know is vauge

 

Maybe an amphipod. They get far larger than copepods. I have a population in a layer of built up sediment below the LR trickle where the water goes into my wet/dry. There are no predators down there so they get pretty big and they kind of look like shrimp. Look up amphipods.

 

look here it is probably one of these Xtalreef also great id site

 

amphipod it is! thanks guys. I kenw id know once someone showed me a pic. That is def what it is. Are these bad? I couldent believe that id see this in there. I had drained the collection cup earlier. Since this is a new skimme I looked at it again tonight and saw this thing swimming around. I couldent believe that it got stuck in there.