When a widespread species is split into two or more smaller taxa, it can be very difficult to correct this on iNat. If there are multiple IDs using the old taxonomy on an observation, it may take a half-dozen or more new IDs to fix what should be an easily resolved problem.
As an example, the ubiquitous Humbug Damselfish (Dascyllus aruanus) was split so that all Indian Ocean specimens are now D. abudafur. (This change actually took place in 2014, but nobody on iNat noticed until now). Unless I am mistaken, there is no easy way to update these observations. There certainly should be.
This came in as a feature request but I moved it to #general because it’s already possible to do taxon splits on iNaturalist. The IDs can be automatically reassigned based on range, if that’s known/possible, and in areas where range overlaps the IDs will be kicked up to the common ancestor. See details at https://www.inaturalist.org/pages/curator+guide#changes Did you flag the taxon for curation?
(It can be messier for non-coastal marine species because there are no Standard Places for marine zones on iNat, but that’s already an open feature request.)
Good to know. If you’re able and willing, D. abudafur needs to be added and all Indian Ocean D. auruanus need to be moved. The only possible exception to this are a few locations in the Eastern Indian Ocean where the two are likely to overlap (Christmas Island, Cocos-Keeling Island, West Australia).
iNaturalist follows FishBase for fish taxonomy, with deviations as the community requests/decides. As of 2018 at least 1) D. abdudafur still wasn’t included in FishBase, 2) iNaturalist intentionally does not attempt to follow the primary literature for most taxa for the reasons listed here, and 3) no one had requested it be added as far as I can find. So please (everyone) feel free to flag taxa for curation when something appears outdated or out-of-line. There is also a huge backlog of taxon flags, so if anyone reading this might want to become a curator to help out, there’s more info here: https://www.inaturalist.org/pages/curator+guide