A Comparative Morphometric Study on Odontobuthus bidentatus and Odontobuthus doriae (Scorpionida: Buthidae) in Iran

Scorpions are one of the most venomous animals which cause serious public health problems. The sting of scorpions can sometimes be fatal depending on the scorpion species involved. So far sixty-six (66) scorpion species have been identified in Iran. Annually, about 40-50000 cases of scorpionism are reported in Iran. Odontobuthus doriae and O. bidentatus are among the most medically important scorpion species in Iran, and they are very similar to each other in coloration, carination, and trichobotrial patterns. In the present study, we conducted a morphometric study to compare some of the important morphological characteristics in order to identify the key differences between these 2 species. Forty-five (45) morphological characters were measured using calipers and stereomicroscope. And fifty-five (55) morphological characters and ratios (Relative of length to width ratio of morphological characters of scorpions) were analyzed. The independent sample t test in SPSS version 24 was used for the statistical analyses in this study. The mean total length, carapace width, length of fixed and moveable fingers, and chelicerae length of O. doriae were greater than those of O. bidentatus in our study area. The morphological measurements showed clear distinction between O. doriae  and O. bidentatus in our study area, and thus, they can be used as morphological identification keys for distinguishing these two species.