Figure 2. Aggressive interactions between male Pantopsalis cheliferoides.

(a) Interactions between both exaggerated morphs (long-slender and short-broad) are initiated when one male approaches another and touches the opponent with its first and second legs. (b) Long-slender males face their opponent, unfold their chelicera so that the second segments are held at right angles to the first, and then rapidly wave their chelicerae in unison, occasionally jabbing towards their opponent. (c) In escalated contests males proceed to grappling before one male retreats. (d) Rather than completely unfolding their chelicerae, a short-broad male (right) approaches a long-slender male (left), unfolds the second segment to a 45 ° angle and moves his chelicerae up and down in a stabbing movement, also jabbing at his opponent in an attempt to pinch onto their chelicerae.