A transparent looking centipede

[Msc]

Hi I am new to this site so hope I am in the right section I noticed a transparent looking centipede ? Out on the sand could only be about centimeter long when I went to take it out with a net it moved like lightening any ideals please

 

[Sniperhank]

It is probably a bristle worm. A picture can help confirm.

 

[mr_X]

Was it hunched over like this-

If so, that's a harmless amphipod.