Sergius Orata (fl. c. 95 BC) was a famed merchant and hydraulic engineer of the Roman Republic.
Sergius was well-known by his contemporaries because of the breeding and commercialization of oysters, in which he can be considered a pioneer. Orata wanted to take advantage of Romans' taste for shellfish, so he developed a new system for breeding oysters. He constructed channels and preys to control sea tides, as well as high vaults over Lucrine Lake.
He is also credited with the invention of the hypocaust, although this is not fully confirmed. All we know for sure is that he invented a certain type of hanging baths ("balneae pensiles"), some kind of relaxing thermal baths; they are usually considered to be hypocausts. He commercialized them as successfully as the oysters, becoming a sign of distinction among patricians. He used to buy villas, construct the baths, and then resell them at higher prices.
The Romans said of Sergius that he could breed oysters on the roof of his house. Sergius Orata grew rich on his inventions; he was distinguished for his love for luxury and refinement. "The orata," Festus noted, "is a kind of fish so called for its golden color (aurata, "golden," also spelled orata). ... Because of this, it's said about the very wealthy Sergius that they called him orata, because he wore two big rings of gold. Some authorities assert that his nickname just comes from the commercialization of those fishes."