Calculanthra was a male Orion who lived in the late 24th century.
Calculanthra was rivals with the father of a wealthy Orion family, until that family suffered hardships and its daughters were auctioned off as Orion slave girls in 2372. Calculanthra desired to buy them as a prize from the ruined family, but instead a group of Moborites bought them on behalf of Quark, who wanted some Orion dabo girls for his bar.
Calculanthra also bought a number of replicators from a Tellarite, then smuggled them to Bajor through Yridian middle men to Manimoujak, while the deal was organized by Ompar Tenzil of the Bajoran government. However, the replicators unknowingly carried a disease that spread across Bajor.
Benjamin Sisko and Quark tracked the replicators to Mephil Trantos, where Nodogascur (Calculanthra's second cousin on his mother's side) pointed them out to him. Calculanthra instructed Nodogascur to organize a band of thugs to beat up Sisko and Quark, but the two fought their way out. Quark got the information they wanted from Calculanthra on the spin of a dabo wheel; if they’d lost, Calculanthra would claim the pair as slaves.
He let them leave, but Calculanthra had been embarrassed before his clan and customers and so changed his mind, choosing to give pursue the USS Defiant with his ship, the Laslapadil and three other Orion raiders. The Defiant was victorious, and destroyed or disabled the four ships.
Calculanthra was very large and strong, even for an Orion male. He was generally suspicious, but enjoyed gambling, even if he had little luck at dabo. (DS9 novel: Wrath of the Prophets)