Ryan Photographic - Belliidae - Big hand crabs
The family Bellidae contains 7 species in 4 genera. I have only photographed the endemic New Zealand species which is reproduced below. A number of scientific studies have been conducted on this species so it is by far and way the best known. Another species is found around both coasts of South America but a cursory search of the internet has not proivided information on the other taxa.
Heterozius rotundifrons Big-hand crab
Heterozius rotundifrons Big-hand crab, male, Somes Island, New Zealand IMG_0054