Specimens of the sea cucumber Synallactes virgulasolida were obtained during sampling operations off western Mexico. Based on a total of 190 specimens and on additional records available in the Scripps Institution of Oceanography collections, new geographical (southern California to Chile) and bathymetric (712‒1300 m) distributions are provided. SEM photographs of ossicles are provided for the first time for this species. New ecological data associated with the presence of this species are also provided: 4.17‒5.81 °C, 0.15‒0.48 ml O2/l, and in 34.40‒34.48 ups. The species occurs in a wide variety of sediments with an organic carbon content of 17.93‒52.02 mg/g (1.79-5.20 % of organic matter) and is occasionally very dense (up to 170.32 orgs/ha). All Mexican records correspond to a bathymetric fringe located below the Oxygen Minimum Zone, thus indicating that S. virgulasolida is able to tolerate hypoxic conditions.
Keywords: Echinodermata, Holothuroidea, Synallactes, deep water, oxygen minimum zone, western Mexico.