These pictures came from the web and I am not certain of the species.
Two Photographs by John White
From Malaysia-Borneo
A fiddler crab from St. Martin
From the following website
These pictures were provided by Chris Lukhaup. It is a Mexicao fiddler crab, found on the gulf Coast near Nautla.
This picture was provided by Chris Lukhaup.
These pictures are of Florida fiddler crabs and were provided by Chris Lukhaup.
From a Japanese website
From the Virtual Museum of Natural History. Photos by Dr. Robert Sprackland.
Although there is no definitive male in these photos, the shape of the carapace is certainly indicitave of Uca. From the linked website:
This photo was emailed to me (unfortunatley I have forgotten from whom). It was taken in Brazil.
From a Russian website.