Xelayan

The Xelayans are an alien species of the Planetary Union in The Orville Series.

Biology
The Xelayans are humanoids, though they possess ridges above their eyebrows. In addition due to the heavy gravity of Xelayas, in Earth gravity their strength is elevated. Xelayans differ from humans in that they don't possess any livers. While the lower gravity of other worlds grant Xelayans superhuman strength, over time this causes their bones to atrophy, making them fragile, unless they commit to proper exercise within a heavy gravity environment.

Culture
Xelayans don't usually join the military thus when one of them does, the Planetary Union bumps them up in the Fleet. Though their culture seems more related and incline to academics.

Source

 * The Orville Season 1: Episode 1: Old Wounds