The Izlians evolved underwater, but adapted to air atmospheres, though ones as moist as possible. They look similar to squids. They communicate using emissions of radiation at various frequencies.
They are more at home in zero-G than nearly every other race in the Union, helping them to be some of the most skilled shipbuilders.
Their personal code of honor is detailed and nearly impenetrable to other species. They are therefore prone to take offense for reasons known only to them. Since they are also one of the wealthiest species in the galaxy, such offenses can have dire consequences.