Oddball aquarium invertebrates.

[RoyalGramma001]

I am relatively new to nano reefs, I have had one for 5 months. I have a 20 gallon tank and I was wondering what are some invertebrates that have cool abilities like pistol shrimp or invertebrates that look bizarre like arrow crabs. What are good editions? 

[sublunary]

There are so many cool things out there!  Here are a few I can think of off the top of my head.

 

If you are looking for something for a species-focused tanks, mantis shrimp are pretty amazing.  They are serious predators though, so no fish and very limited clean up crew in their tanks.

 

If you don't mind sacrificing starfish for the cause, harlequin shrimp and bongo shrimp are obligate echinoderm feeders and both look really neat.

 

For reef-safe crabs, I like porcelain crabs - who filter-feed with fan-like mouthparts - and pom pom crabs - who carry around tiny anemones to help catch food. 

 

For non reef-safe crabs, I think decorator crabs and sponge crabs are really neat.  

 

For snail-like things, cowries and scutus look cool - their fleshy parts stretch out to cover their shells.  I also love chitons, because they're so ancient looking. 

 

Urchins are also pretty of cool, though the most interesting ones aren't reef safe or get huge. Still worth checking out. 

 

[RoyalGramma001]

I might get chitons those are really neat!