Regarding the selling issue, I've noted it, and it should be fixed in the next release. The shrimp are being sold, but their visuals aren't updating at the right time. For the compendium, if they're unlocked there and you're able to claim a reward for them, that means you've bred them. So somewhere in your tank there should be a shrimp matching it. In future versions, I'll include a note or a batch of dialogue explaining that more thoroughly.
Thank you for your feedback and for taking the time to play this Alpha release. Your feedback will help me release something better next time!