There is currently no pet insurance plan on the market for fish. However, fish owners do have an alternative option through Pet Assure, a veterinary discount plan. A Pet Assure plan can offer up to 25% off aquatic veterinary care.There is currently no pet insurance plan on the market for fish. However, fish owners do have an alternative option through Pet Assure, a veterinary discount plan. A Pet Assure plan can offer up to 25% off aquatic veterinary care.