Sexing Pandinus spp and Heterometrus spp

Sexing Pandinus spp and Heterometrus spp

1) Sexing via the Shape of the Genital Operculum (High accuracy)

Genital Operculum is located at the underside of a scorpion.

The location of Genital Operculum is identical for both males and females:



Males: They have an "oval shaped" Genital Operculum

Female: They have a "heart-shape" Genital Operculum and it's pointed tip is facing towards the metasoma (scorpion's tail). Refer to the reference shot i took on my pair of specimens.



2) Comparing the size of pectines (feather-looking thing near the Genital Operculum

As you can see from the picture above, males' pectine are much thicker and longer than female’s. This may be a feasible sexing method if you have a few specimens to compare with.

A pectine tooth count (PTC) will not be effective for sexing as the PTC of males and females overlap in numbers.

Method one should always be your first attempt on sexing


The following is another close-up shot on female's "heart-shaped operculum"



Note: There may be slight variation from both sexes. E.g. there can be a few types of "Oval-shaped" Genital Operculum of males but the distinguishing pointed tips of the female's "Heart-shaped" Genital Operculum should be a clear indicator on separating females from males.

Regards,
GS