I see them at the LFS all the time, possibly Amphimedon spp., Aplysina spp., or Ptilocaulis spp. Names taken from Ron Shimeks Marine Invertebrates. You could also call it Orange Tree Sponge.
They do require alot of particulate matter, and should be fed something like Phytoplankton, or other simialr food. Kepp away from bright light, and provide good flow, but not direct flow.