Originally a beautiful garden planet, Tiburon became completely urbanized and polluted, so much so that the immune systems of the Tiburonese were suppressed through toxins. What's more, the planet and its system were to experience several outbreaks of plague, with the first occurring in the year 2107. Although much attention was devoted to eradicating these plagues, the bacterial strains mutated faster than the Tiburonese could develop cures. By 2122, the Tiburonese wore full-body anti-contamination suits from cradle to grave.
It was in 2130 that Tiburon surrendered to the Terran Empire. By this time, the Tiburonese had colonized several Class M planets and occupied a world known as Ucali. Although it had been the Ucali natives who had conquered Tiburon, over the years, the Tiburonese had converted the Ucali to their more materialistic culture. Moreover, they had interbred and were no longer distinguishable as two separate species. (Decipher RPG module: Through a Glass, Darkly)