yep, those look like those same ones in the other post. these are a major terror for those of us that have dwarf seahorses. Everyone here on RC likes to treat with panacur(a dog dewormer) which will not harm your bio cycle however, it will stay locked in the sand for many years even with regular water changes and carbon. and will also harm most inverts, but not all. Short of doing that your only option is to break the tank down and start all new. if reusing anything out of the infected tank it needs to go through freshwater and formalin dips and be isolated and redipped after six weeks before going into the new setup, or they will be back. Normally worse than they were the first time. They normally come into our tanks in the rock and may stay dormant for many years before coming out. Some go as far as scrubbing everything down with a toothbrush while being isolated to help ensure no nasties are attached. it only takes one, yes one drop of seawater with these things to infect your tank. I haven't heard of them really hurting anything in the tank other than Dwarf Seahorses because of their size, so I guess thats good news.