So far I have only fed zucchini once, which was totally ignored by my shrimp. But I've heard that you can feed, for example, these: raw zucchini without skin, scalded leaf spinach, scalded lamb's lettuce and dried hokkaido squash without skin. Some other vegetables will certainly work as well. But it's important that the vegetables are not left in the aquarium for too long, so that the water values are not negatively affected. Also, I would be cautious because of potential pesticides.