Gaussia

Gaussia is a genus of small marine copepods, crustaceans that form part of the zooplankton in oceans worldwide. Members of the genus are typically free-living, planktonic creatures that feed on microalgae and detritus, and they play a role in marine food webs. Species occur in a range of oceanic environments, from coastal to open ocean waters, and in various depths depending on the species.

Gaussia princeps is the best-known member of the genus. This species gained scientific prominence because it is the source of Gaussia luciferase (GLuc), a small, secreted luciferase enzyme widely used as a reporter in molecular biology. GLuc catalyzes the oxidation of coelenterazine to emit light and is valued for high signal intensity, rapid secretion, and compatibility with diverse assay formats. The enzyme has been utilized in gene expression studies, imaging, and high-sensitivity assays in both cell culture and living organisms.

Taxonomic notes: Gaussia belongs to the copepod crustaceans (subclass Copepoda) and comprises multiple species described by various taxonomists. As with many copepod groups, species boundaries and classifications are refined over time with morphological and molecular data.