I have a 3g Eclipse with a betta, oto, and a ghost shrimp. They're all nice and serve their purpose, but the shrimp is really pretty cool to watch as he cleans the substrate of extra food. Are there any other shrimp I can keep in my tank? I've had ghost shrimp on and off in this tank. The first was eaten after a month, the second was eaten overnight! Can I keep more than one species of shrimp? If not, what should I get next, and how many?