Macroalgae hitchhiker ID

[GothFishKeeper]

I ordered some blue hypnea online for my dwarf seahorse tank, they sent two VERY large portions of it. The first bag that I already put in the tank seemed to be clean, but I still rinsed it in fresh saltwater and hopefully there isn’t anything on it. This second bag has hydroids attached to the inside, rock and sand in the algae, and then there’s this thing. What in the world is it? Either way I’m not putting this one in a tank that’ll have seahorses in it, but I absolutely have to know what the heck this is.

 

[vetteguy53081]

I ordered some blue hypnea online for my dwarf seahorse tank, they sent two VERY large portions of it. The first bag that I already put in the tank seemed to be clean, but I still rinsed it in fresh saltwater and hopefully there isn’t anything on it. This second bag has hydroids attached to the inside, rock and sand in the algae, and then there’s this thing. What in the world is it? Either way I’m not putting this one in a tank that’ll have seahorses in it, but I absolutely have to know what the heck this is.

I believe this is a dorvillidae worm (cousin to bristle and reef safe.) I dont believe this a eunicid
pick off or cut off the hydroids