Abstract
A total of 12,129 specimens of Macromedaeus distinguendus were examined for handedness. The percentage of left-handed crabs was 21.5 % in males and 20.8 % in females. No significant increase in the ratio of left-handed crabs by size was confirmed. Examination of a total of 4,453 specimens of Leptodius exaratus showed that the species has an equal ratio with regard to handedness.
