Respiration

Abstract

Periplaneta americana is a flat, broad insect specialized for hiding in narrow crevices during the day and for being highly active at night. It survives well in dry places, runs extremely rapidly, but flies only rarely in the wild. It can also jump, and it can swim on the water surface at considerable speed. Some of these features of its life are reflected in specializations of the tracheal system which is able to meet the high demands of active locomotion, restrict water loss to a minimum when it is quiescent, and perform a number of non-respiratory functions. Tracheal morphology is based on a repeating segmental plan linked by longitudinal trunks which unite the whole system. The basic plan is homologous throughout the Dictyoptera and is most highly developed in the Blaberidae (Baudet and Sellier, 1975). For an insect so popular in biological research, there have been surprisingly few studies of its respiratory system. No detailed account of the tracheal system is known, and its spiracular and ventilatory mechanisms have received less attention than those of many other species. I shall therefore include some mention of studies on other cockroach species, particularly of Blaberidae, to supplement what is known of P. americana, since the basic anatomy and physiology are probably similar throughout the order.