Global distribution and overlap of fiddler crabs

These data come from a GIS study of geographic ranges of fiddler crabs throughout the world, analyzed in 2019. They consist of  (1).shp and related files usable as GIS source material in the ESRI data software system; (2) range length data for all species studied in km of coastline; (3) centroid data for all species, given as latitude and longitude; (4) Overlaps of all species, given as number of species overlapped within a biogeographic zone (Indo-West Pacific IWP, Eastern Pacific EPAC, and Western Atlantic WATL.

Methods
Source geographic ranges of fiddler crab species came from fiddlercrab.info. We digitized ranges from the fiddler crab website as of July 2019 (http://www.fiddlercrab.info.) Coastline data was extracted from https://www.ngdc.noaa.gov/mgg/shorelines/ and was extracted using ArcMap v 10.6 (Environmental Systems Research Institute Corporation, Redlands, California - ESRI), at the “intermediate” resolution shapefile to an ocean base map provided by ESRI. Range maps were projected to World Mercator using coastline data and digitized coastal species ranges.