ID red macro

[Mike4284m]

Picked this up at the beach here in SE Florida. Any ideas? I'm helpless when it comes to iding most reds.

 

[lemures-ex]

I had a bunch of this that I got from the beach as well. It died off pretty quick but I would like more if I can get it to live. Any suggestions?

 

[graveyardworm]

Gelidium spp. ?

 

[Mike4284m]

Could be, but I'm not sure. Be pretty cool if it is, since this is where agar comes from (spoken like a true science nerd).

I've only had it in the tank for less than 48 hours, so I don't know if it will last.