The study of fish is called Ichthyology (from Greek: ἰχθυ, ikhthu, fish; and λόγος, logos, knowledge). So that means a Scientific name for fish might be Ichthy (plural form, Icthyes) . Of course, Pisces (pie-seez) is the name of the constellation known as The Fishes, and piscis (pis-kis) is the Latin word for fish (pisce - pis-kee - is the plural form of piscis).