No grass shrimp that I know of, I'm not even sure I know what a grass shrimp is, we do have crawdads in the pond, both the LMBs and BGs love them. We also have snails and small leeches as well, about the only time I see the leeches is durring the summer when they attach themselves to the inside roof of a LMBs mouth. We do have a wide variety interesting inscects, I occasionaly see some sort walking stick in the water that's 3" long, we also have thousands of dragon flies in 4-5 different variety's every summer. We have several king fishers that make their daily meals of small BG's caught out of the pond in the summer. I even once saw a blue heron down a 9" BG, man did that look funny going down it's throat.