Field observation of male-male fighting during a sexual interaction in the whip scorpion Typopeltis stimpsonii (Wood 1862) (Arachnida: Uropygi)

Abstract

We observed male-male fighting during the mating process of the whip scorpion Typopeltis stimpsomi (Wood 1862) in the field on Amami-Oshima Island, Japan, and this may be the first report of ago- nistic behavior between male whip scorpions. The fight proceeded in the form of physical contact activities, such as wrestling, as the males grappled and tackled each other using their pedipalps and lifted, rotated, and mounted the opponent. Each male held one of the two antenniform legs of the female with his chelicerae throughout the entire fight even during aggressive physical contact. The males fought without chemical spraying, supporting previous studies of the function of chemical spray as a defense against predators. The fight was terminated by ant attacks, probably due to a decreased sensitivity of the males, who concentrated on fighting, to surrounding environmental risks. Additional observations are desirable to promote further re- search on whip scorpions, as few studies have been conducted in the field.