The functional morphology of the respiratory system of the Holothyrida (= Tetrastigmata) Acari: Anactinotrichida

Abstract

The respiratory system of Holothyrus coccinella Gervais (Holothyridae) and Allothyrus australasiae (Womersley) (Allothyridae) were examined. The stigma‐peritreme complex is connected to tracheae and ventilated by indirect muscles. The peritreme provides an alternative route for the entry of air into the tracheal system, should a stigma be occluded by debris and retards water vapour transpiration, the mechanisms of which are compared in the two species.

The respiratory system of Halarachne halichoeri (Halarachnidae: Gamasida: Anactinotrichida)

“…The location of the occlusion suggests that it is secreted by the tegumentary glands which debouch directly into the stigmatic atrium. Similar glandular ducts are associated with primary atrial chambers of the spiracular plate in the Ixodidae (Ixodida = Metastigmata) (Pugh, King & Fordy, 1988, 1990a, and the peritreme of the Holothyrida (Pugh et al, 1991), but this is their first record from the gamasid peritreme. The function(s) of spiracular or peritrematic glands is/are unknown, though they resemble the glands associated with the tick integument (Hughes, 1959;Sixl.…”

“…But, with the exception of the layer covering the major papillae in the peritrematic groove of Hofothyrus sp. (Holothyrida) (Pugh et al, 1991). cerotegument-like features have not been reported in the respiratory systems of the Anactinotrichida.…”

An application of scanned focused ion beam milling to studies on the internal morphology of small arthropods

“…Acarine respiratory systems have been studied extensively with the aid of the SEM (Hinton, 1971;Woolley, 1972;Witalinski, 1979;Pugh et al, 1987Pugh et al, , 1988Pugh et al, , 1991. In this technique, (usually) alcohol-fixed material is rehydrated, fractured with a sharp blade, possibly ultrasonically cleaned, then air, critical point or freeze dried, mounted, gold coated and viewed in the SEM.…”

The respiratory system of the femaleVarroa jacobsoni (Oudemans): its adaptations to a range of environmental conditions

“…This continuous outflow of gas from the body generates a negative suction pressure within the tracheal system (Punt, 1950;Pugh et al, 1991 ). This mechanism probably occurs in V. jacobsoni, and would be aided by its very flattened shape, providing a high surface to volume ratio.…”