Carnivorous harp sponge

YouTube link. 

Very cool creature newly discovered, and described at Nature:

...the vertical branches and horizontal stolons that make up the sponge’s basic harp-like structure, called a vane, are covered in barbed hooks and spines. They found that a number of crustacean prey were passively ensnared on these branches thanks to the Velcro-like hooks and then aggressively enclosed in a cavity to be dismembered into small, digestible particles, which provided direct evidence of the species’ carnivorous appetites...

They can have 1-6 vanes, each supporting a number of equidistant vertical branches, and each of these end in swollen terminal balls. According to the researchers, these terminal balls produce condensed packets of sperm called spermatophores, which are released into the surrounding water in the hopes of fertilising other harp sponges in the area...