Souleyet was naturalist-surgeon on the voyage of La Bonite, which circumnavigated the globe between February 1836 and November 1837 under Auguste Nicolas Vaillant (1793–1858). In the Pacific he studied marine molluscs. After the death of Joseph Fortuné Théodore Eydoux (1802–1841), Souleyet completed the zoological section of the voyage's official report in 1852.
He named a number of marine molluscs and fish, but most of his new taxa were validated already two years earlier by John Edward Gray, who Latinized all vernacular names published earlier in an undated (1842 ?) atlas by Eydoux & Souleyet. He is himself commemorated in the scientific name of the Streak-headed Woodcreeper, Lepidocolaptes souleyetii, named for him by DesMurs and in the Heteropod Protatlanta souleyeti by Edgar A. Smith in 1888.