Piscis

Piscis is a Latin noun meaning “fish.” The standard singular form in classical Latin is piscis and the common plural form is pisces. The root appears in a wide range of modern terms, including piscine (fish-like), piscatorial (relating to fishing), and pisciculture (fish farming). In Latin proper names, piscis appears in phrases such as Piscis Austrinus, the Southern Fish, used for a real constellation.

In biology and the history of science, Pisces was once used as a formal taxonomic group to include all fishes. In early taxonomic systems, it was treated as a class or a superclass, sometimes divided into orders. Contemporary systematics no longer recognizes Pisces as a valid taxon; fishes are distributed across multiple clades, notably Osteichthyes (bony fishes) and Chondrichthyes (cartilaginous fishes). The term survives primarily in historical contexts and in language related to fish.

In astronomy, Piscis appears in several Latin-era names. The best-known is Piscis Austrinus, the Southern Fish, a real constellation located near Cetus and Grus. The zodiac sign associated with water and dual fates is Pisces (plural), not Piscis, and it represents two fish bound together. The zodiacal constellation Pisces and the astrological sign share the same Latin roots but refer to different celestial contexts: one a defined star group, the other a symbolic segment of the sky used in astrology.

In language and culture, the root pisc- gives rise to numerous terms describing fish-related concepts, including piscine, piscatorial, piscivore (an animal that eats fish), and piscicide (an agent that kills fish). The word Piscis thus functions as a linguistic base linking biology, astronomy, and culture.