So I had previously used Ward's Science in the past to get fruit fly medium. I tried searching for them again since they typically had live organisms and found they are now Boreal Science (www.boreal.com). If you need micro-fauna to add some variety to the diet of carnivorous tadpoles, small fish, or just want to add some invertebrates to your water feature to clean you can find a number on their website. Shipping is costly, but for starter culture prices it isn't bad. Some of what they have: Daphnia magna Ostracods Copepods Amphipods Aquatic Isopods I suggest using their search function as not everything is under the expected categories and some links lead to broken pages on my browser. I have a bunch on order and expect them by Friday, so I'll let you know how they fair. I'll be keeping them in their own culture jars for a bit before I start seeding my own vivariums. Even though they are bred in lab conditions I do not feel like introducing hydra or planarians to my tanks. I plan to use the Ostracods and Aquatic Isopods as cleaners for my newt, crab, and larger frog enclosures while the copepods and amphipods I plan to raise as food for my fish. I hope it all goes well.