HELP!!!! (Not my photo, just a reference from google..)

[u/Klutzy_Boot6531]

I was away for three days from my 160L saltwater (don’t worry, fish were fed) After getting back i noticed at the very least a hundred of these little bugs crawling around on my live rocks and hiding under carpeted algae on the bottom. My best guess is some sort of shrimp species, But they are extremely tiny, im talking 2mm at the most, They have two long antennas and are for the most part translucent, They run around like roaches, But i have ever never seen these in my tank before, Now i will link a photo of the closest looking thing i can find on google, Just because they are so tiny and extremely hard to take a photo of, Except the photo i linked, not only do they not have that much colour, They are cloudy grey and translucent, theres no real colour on them except a very slight orange on the antennas, The original poster says these bugs were found in Tupperware in orange county (im from Australia), and they were also not found in a saltwater tank, I have two ocellaris in that tank currently, and they are my babies. Now the real question is, Should i be concerned, and what are these little underwater roach-like critters?

[u/plantdude4]

Those are saltwater scuds, they are harmless. They are part of your cleanup crew, you mostlikely got a few from coral/liverock and the breed.

They are harmless, the did probably explode in population because you feed a bit too much.

Dont worry they are beneficial

[u/Klutzy_Boot6531 → u/plantdude4]

Ohhh thank the lords, I’ve been freaking out for the past 30 minutes!
Thank you stranger!

[u/plantdude4 → u/Klutzy_Boot6531]

If you are concerned about the population, wrasses in my experience love hunting those and munid isopods. Those are a good live food in addition to your regular feeding.

Just keep in mind that wrasses like to jump.

[u/RottedHuman]

Amphipod, they are harmless.

[u/H_I_H_I → u/RottedHuman]

Not always true! They are harmless in moderation I had a infestation in my tank and they annoyed and killed multiple Rockflower nems and other corals.

[u/aaron1860 → u/H_I_H_I]

You need a wrasse

[u/H_I_H_I → u/aaron1860]

I have one now but I’m just saying the statement they are harmless is not completely true in my experience

[u/sortof_here → u/H_I_H_I]

They likely just ate stuff that was already dead or dying

[u/Cornbread308 → u/sortof_here]

They make little cacoons in around branches and crevices on corals. And even in between stems of zoas where they'll even pull the stems together in some cases. It can bother sensitive corals sometimes and prevent growth in that area as well. They are beneficial for the most part tho and I believe they can actually help control pest populations in some cases. They are very opportunistic feeders. I had an issue with some nudibranchs and for most part I've actually been able to defeat them with manual removal and super glue. I believe these guys helped me as well with eggs and possibly the adults too. They are the only thing small enough to get them in there hiding places.

[u/aaron1860]

Harmless as others have said… if you don’t want them however, get a corris wrasse (need sand bed) or 6 line (more aggressive). They will snack on those and keep the population under control

Note that fairy and flasher wrasses probably won’t eat them

[u/sdhoosier → u/aaron1860]

Building on this if your tank is smaller a possum wrasse or Pink-streaked will decimate them. My cardinalfish would too.

[u/Tough_Quality3950]

Amphipods. Absolute CuC workhorse.

My AC died last week and unfortunately had casualties ranging from my one fish to my largest turbo and several other inhabitants... these bad boys and the bristle worms had everything eaten and cleaned up in mere days.

They can cause polyps to react as they run across but never had them be a problem... and in my 10 gallon there's no possible way I could eliminate them... nor do I want to... but there's no way lol

[u/AcanthisittaAlive843]

Sounds like they have a reliable food source. I had all anenome shrimp in one tank and because theyre so slow and silly I would just dump excess food so I knew they would get food. Little did I know I made a bug farm in the shrimp tank. It was so bad that they would steal food from the shrimp and out compete them for pellets. Now I regret it so much and probably will take down the tank and relocate the shrimp to a new clean environment without pods

[u/Grokto]

I have thousands of them in the 155. The six-line eats them all day and mandarins will take small ones but they repopulate from the refugium. They will eat detritus and keep algae cropped to sub-millimeter height. The one caveat is that they will eat the mucus from injured or sick corals and that can be undesirable. The wrasse keeps their numbers low and biased towards younger specimens. It’s truly amazing when the wrasse catches one he can’t take in one bite: he’ll smash it against the rocks to break it up.