In addition to their eight, simple camera-type eyes, their antenniform
forelegs are covered in thousands of receptor setae, tuned to different environmental stimuli, that provide sensory information that guides their spatial behavior.
Anatomy and physiology of giant neurons in the antenniform
leg of the amblypygid Phrynus marginemaculatus.
Whip spiders (Arachnida, Amblypygi) possess a number of morphological specializations including enlarged spiny pedipalps and elongated antenniform forelegs which they use as feelers.
The antenniform legs, and their GNs, are not necessary for successful prey capture since a whip spider that has autotomized both of these limbs can still capture prey (Beck & Gorke 1974; Weygoldt 1995, 2000).
Prolonged associations within the social groups include active aggregation, high levels of tolerance, and frequent amicable tactile interactions with their antenniform first legs ("whips") to neighboring individuals.
Behavioral Observations.--The sensory and social lives of amblypygids are centered on the thin antenniform first pair of legs (or "whips"), which are extensively used for odor discrimination (Hebets & Chapman 2000), spatial location (Hebets 2002), and tactile contact between individuals (Rayor & Taylor 2006; Rayor 2007).
These elongate, motile sense organs are referred to as antenniform legs.
The antenniform legs are very long relative to body size.
Kinematics.--Like other phalangid harvestmen, Leiobunum vittatum behaved as a functional hexapod, the antenniform
second legs being used primarily as tactile organs.
The whips are modified into thin antenniform
sensory structures that can measure three to six times the length of the body.
Agonistic encounters between males are characterized by varying degrees of pedipalpal opening, elevation displays, and rapid flicking (~ 29 Hz) of the antenniform
Also on an average, the femora (2.3 mm) and tibiae (7.2 mm) of the antenniform
legs are shorter than in females.