Little "critters" on rock

[joshsliftedzj]

Saw some worm/ centipede looking bugs crawling around on my lr. They are kinda clear and bluish tint. any idea's to what they are. Too fast to get a pic and the are pretty small. Don't think they are hurting anything. But i am a total noob to sw tanks. Thanks in advance for any help
Josh

 

[fishcatch22]

They are called Amphipods, and are perfectly harmless, natural, and actually essential to a well-balanced marine setup. They are small crustaceans that live globally and a major component of Zooplankton in many places, along with other "pod" type crustaceans, such as copepods. They mostly feed on algae. You'll mostly only see them at night once they get settled in.

 

[joshsliftedzj]

Had a feeling that is what the are. Look neat crawiling around on the rock. Thanks for the anwser