These guys are so interesting I just had add to this post.
Fairy shrimps would be extinct except that they have adapted to unique ecosystems that are unfit for fish. Indeed, one never finds them in waters that support fish. One of the more interesting adaptations is their ability to produce embryos (called cysts) in a suspended state of development that can hatch when conditions are favorable. They can be years old and in some cases decades old and still hatch. They can be brought to temperatures that would cook bacteria ... and still hatch. They can be frozen for extended periods ... and still hatch. Rather remarkable creatures.
This ability to produce offspring in a suspended state of development allows them to inhabit temporary pools. But even this quality would be insufficient if they had not also adapted to make use of the this habitat over periods of time that are no less than astonishing. Temporary pools waste away and fairy shrimps must grow rapidly, reach adulthood, and produce offspring in the short time the habitat will support them. Some fairy shrimp have evolved the ability to hatch, grow to reproductive size in 7 days and produce > 6000 embryos during their short lifetime <30 day. The most remarkable part of it is that they can grow to 5000 times their hatch weight in the first 7 days.
To put that in perspective it would be like a FHM hatching out on Sunday morning and being 3.5" long the following Saturday evening.
This ability to use everything the habitat can produce for them as fast as the habitat can produce it leads to some challenges for the Texas Parks and Wildlife Department’s Jasper fish hatchery
where LMB fingerlings are reared. Because they drain the ponds each year, they set up the intermittent conditions that favor fairy shrimp. In the link they describe how when they hatch they can consume a bloom in just a few short days. Because they grow faster than LMB fry, the LMB fry cannot use them for food and the LMB that hatch starve. To manage around them they flood and allow them to hatch then drain the pond and refill. Fairy shrimp will still hatch ... but they are much reduced in number allowing the LMB fry rearing ponds to produce zooplankton for the crop of LMB fry.
OK. So one might think that maybe a creature that grows this fast wouldn't be worth much as fish food. But ... if he did he would be mistaken. This paper
references an analysis made by Saengphan (2005) showed that the composition of fairy shrimp is 64.94% protein, 5.07% fat, 17.96% carbohydrate, and 8.40% ash. There is currently interest to exploit these creatures in aquaculture.
Even so, its more complicated than just adding some fairy shrimp to pond with fish. They would be eaten quickly and soon be extirpated. To exploit them in permanent body of water with fish, one would need to have a vernal nursery for the production of cysts. Still I have to wonder who among the pond boss family might try to exploit its potential in one way or another. Some possible ideas.
1. There are some winter species that only hatch at temps less than 50 and that could produce additional winter forage for intermediate and larger sized panfish.
2. An introduction timed around the LMB spawn might limit LMB fry survival easing the LMB culling effort? Perhaps providing a boon of forage for adult BG leading into their spawn?
3. Perhaps summer species could provide clean up in advanced fingerling production for lepomis, LMB, or HSB?
I don't know. To get the most out of them one's going to have to work at it and it seems a lot easier to have some shredders like PK shrimp and/or Hyallela Azteca instead that are capable of persisting in permanent waters with fish.