Hello!! Yes, there are as many fruit as fish in veggie mode.
Just a heads-up, you may still see references to fish in the dialogue, and the shopkeeper gives you the nickname "Fish Hunter". And also the final boss is a fish.
For the main gameplay, you will see fruits/veggies that replace the fish, and they'll even fill out in your journal as you catch them. Each fish has a fruit/veggie counterpart :)
I hope this answers your question! Let me know if you have any more questions! 💚