There are two large trachea running parallel to each other just beneath the integument along the dorsal midline of the abdomen. In some species, including Ammotrechella , they can be seen through the integument of the posterior abdomen as branching white tubes. These trachea are moved toward and away from each other in periodic bursts of rhythmic pulsations. This can be observed through the integument of living Ammotrechella . The body and appendages are covered with fine long sensory setae that detect mechanical disturbances such as air movements, vibrations, and direct touch.
Excretion is accomplished by Malpighian tubules and a pair of coxal glands.
The coxal glands open via nephridiopores at the base of the pedipalps. The heart is a short tube in the posterior cephalothorax and abdomen. It has eight ostia. It is not visible without dissection. Invertebrate Zoology , Vol.