The Emperor Scorpion 

Description

The common emperor scorpion is very large, heavily built species, typically
described as the world's largest scorpion. Some have reportedly exceeded eight
inches in length, but normal is closer to between five and seven inches. The
largest I've ever seen was just over seven inches. In overall size and weight it is
the largest, but not the longest. Male Hadogenes troglodytes (Peters) may reach
nine inches in length, but most of that length is in the long and narrow metasoma
(tail).

The overall color is usually glossy black, but some may be dark brown and
occasionally a greenish hue. The pedipalp chela or "pincers" may have a
reddish-brown hue, and are very granular in texture. There are numerous, clearly
visible sensory "hairs" on the pedipalps, metasoma and telson. The telson is
reddish-brown with adults and yellowish with immatures. The telson of a 2nd
instar will be white, but becomes darker with each molt.

Males can be distinguished from females by the length of the pectines. The
pectines (ventral comb-like structures just behind the fourth pair of legs) of the
male are clearly longer. If you are new to keeping scorpions, you will need to
have both sexes present to compare them and determine which are males or
females.