To include synonyms and other common names in the species list used by the Observations survey, run the attached query in Biotics and export it to a .csv file. Name it species.csv and use it to update the species.csv in AGOL (or Enterprise/Portal if that's where the survey is). Doing so will ensure that the changes are pushed to those using the survey, assuming that the species.csv is linked within your survey. If this sounds unfamiliar to you, see the Add csv files to ArcGIS.com and link them to the survey section of the Observations_V14.docx.