Birail Riyannis

Birail "Biri" Riyannis, née Izer, was a female Trill active as a science officer in the Federation Starfleet in the early 25th century. 

Biography
The daughter of a Starfleet non-commissioned officer, Pallas Izer, Biri was discouraged from joining Starfleet by her father Jonek after her mother was killed aboard the USS Shanghai at the Second Battle of Chin'toka. However, after being implanted with the Riyannis symbiont after Pirka Riyannis was declared clinically dead following an aircar accident, Biri attended Starfleet Academy. Rear Admiral Ezri Dax served as her field docent. ("Tinker, Golfer, Doctor, Trill")

In 2407 Biri held the rank of lieutenant and was a laboratory officer working in Starfleet Academy's biology department. On 27 January she was assigned to play the role of chief science officer to Brevet Lieutenant Commander Kanril Eleya during the latter's Kobayashi Maru scenario. She agreed to become the Bajoran's permanent deparment head afterwards. ("The Universe Doesn't Cheat")

In 2410, Biri beamed down to Orvis II as part of an away team to investigate a Preserver installation. When the team was attacked by the Breen, Biri was forced to hide out on the glacier overnight with three other members of the party, then took part in the rescue of their companions when the Bajor returned. ("Frostbite")

Biri completed her zhian'tara at Deep Space 9 while the Bajor was being partially refitted for operations in the Delta Quadrant. ("Tinker, Golfer, Doctor, Trill")

Behind the scenes
Biri Riyannis is one of 's science bridge officers under Kanril Eleya in.