If you were looking for Sponge Bob while exploring the sea, you might have run into his cousins a couple of times already, the barrel sponges! And if you think they’re boring, think again!
-Due to its shape, it provides habitat and shelter for many species of fishes and invertebrates, so look inside them next time and perhaps you’ll find a nice surprise!
-They’re hermaphrodite, and while spawning, they release large clouds of sperm(but not their eggs) and through their filter feeding behavior, they will filter out sperm from other individuals to fertilize their eggs. Once mature, they will eventually release their larvae for other baby sponges to grow. This process will also provide a delicacy for lucky fishes nearby.
-These primitive animals, can live for as long as 2000 years and more!
-They have the capability to reform themselves, once destroyed. Their cells can swim back together and go back to form the initial shape (although will require a lot of time and energy).
-And if this didn’t fascinate you enough, check this out to see how they filter and pump out water!
https://youtu.be/pTZ211cIjX8
Source: https://oceana.org/…/corals-and-other-i…/giant-barrel-sponge
Ten Knots Group Environment and Sustainability 
What do you think?