Editor: Michael Rex
Latitudinal diversity relationships of fiddler crabs: biogeographic differences united by temperature
Article first published online: 9 MAY 2013
© 2013 John Wiley & Sons Ltd
Global Ecology and Biogeography
Volume 22, Issue 9, pages 1050–1059, September 2013
How to Cite
Levinton, J. and Mackie, J. (2013), Latitudinal diversity relationships of fiddler crabs: biogeographic differences united by temperature. Global Ecology and Biogeography, 22: 1050–1059. doi: 10.1111/geb.12064
- Issue published online: 12 AUG 2013
- Article first published online: 9 MAY 2013
- fiddler crabs;
To investigate whether latitudinal diversity gradients differ among biogeographic realms for members of a closely related clade and to examine whether differences can be explained by environmental differences such as the temperature gradient.
Indo-Pacific, eastern Pacific and western Atlantic temperate to tropical coastal intertidal.
We digitized the ranges of fiddler crabs (Decapoda, Ocypodidae, genus Uca) and calculated standing diversity as a function of latitude in the Indo-west-Pacific, eastern-Pacific Americas and western Atlantic regions. We examined correlations between diversity and summer sea surface temperature, water column primary productivity, and also investigated the contribution of spatial autocorrelation.
There was a latitudinal diversity gradient with a peak in the tropics or subtropics, but richness as a function of latitude differed by region. The western Atlantic had a broad zone of equal diversity with a peak that corresponds to the Gulf of Mexico–Caribbean Basin. The eastern Pacific had a distinct peak of diversity at about 10° N latitude corresponding to Panama. The Indo-west-Pacific had a broad relatively flat upper level of diversity, reaching a peak at about 20° S latitude corresponding to the north coast of Australia. In both the eastern Pacific and western Atlantic, Northern Hemisphere diversity was greater than Southern Hemisphere. Species richness of the three regions was positively and strongly correlated with air and sea surface temperature at the start of summer. In contrast, diversities were weakly and inconsistently correlated with productivity.
This paper shows that a physical factor is more important in explaining latitude distributions than regional cladal structure or presumed dispersal patterns. While observed diversity–latitude functions are region specific, the feature seen across regions to most strongly explaining the pattern is temperature.