| Definition | Reported data ID | Presence ("present") or absence ("absent") of apple snails | Year of the observation date | Month of the observation date. Records that did not specify the month were indicated by "-" (unknown) or e.g. "7_9" (from July to September). | Day of the observation date. Records that did not specify the day were indicated by "-" (unknown) or e.g. "21_28" (from 21st to 28th of the month). | Latitude of the observation location (degree) | Longitude of the observation location (degree) | Observation method ("photograph" or "visual confirmation") | Input "shell" if the record was confirmed by snail shell observation. Null values were filled with "-". | The name of volunteer in English letters. Some names denote nicknames. Input "-" if the volunteer wanted to be anonymous. The names that begin with "@" are twitter screen names. | The name of volunteer in original letters. Input rule is same as with recordedBy. |