Need help to ID

[Bigtex817]

my tank is 65 days old but just recently found some critters on an empty shell that I got for my hermit crabs. Please help I'd and if good or bad for the tank? Sorry in advance for the bad picture. There are 3 red ones and some smaller ones on the other side of the shell.

 

[KJ]

Vermetid (Tube Snail)
http://www.advancedaquarist.com/blog/vermetid-snails-harm-coral-reefs-with-multiprong-attack

 

[Bigtex817]

Are those good for my tank or bad?

 

[KJ]

Are those good for my tank or bad?

http://reefkeeping.com/issues/2005-01/rs/index.php

 

[Cnidoblast]

Super glue the tops of the tubes shut