Stefan K. Hetz
Department of Animal Physiology, Humboldt Universitšt zu Berlin,
D-10115 Berlin, Germany
On the basis of their
well developed tracheal gas exchange system, insects are generally
considered to lack a circulatory system especially designed for
respiratory gas transport. Although most insect species do not
possess any pigments for oxygen transport, there is founded evidence
for a significant interaction of circulatory and respiratory
function as pointed out by Wasserthal (1996). Direct interaction of
haemolymph circulation and tracheal ventilation (Hetz et al. 1999)
may be supported by activity of intersegmental muscles, by the
coelopulse system (Slama 2000) and further accessory pulsatile
organs (as reviewed by Pass 2000). Accordingly, during specific
conditions haemolymph convection may represent an important factor
for respiratory gas transport. Recently, new techniques better
suited for small specimens have been developed for the study of
aspects related to circulation-mediated respiratory gas exchange. An
overview of current techniques and recent data is presented and
possible future developments are discussed by this paper.
WASSERTHAL, L. T. (1996). Interaction of circulation and tracheal
ventilation in holometabolous insects. ADVANCES IN INSECT PHYSIOLOGY
HETZ, S. K., PSOTA, E.
and WASSERTHAL, L. T. (1999). Roles of aorta, ostia and tracheae in
heartbeat and respiratory gas exchange in pupae of Troides
rhadamantus Staudinger 1888 and Ornithoptera priamus L. 1758
(Lepidoptera, Papilionidae). INTERNATIONAL JOURNAL OF INSECT
MORPHOLOGY & EMBRYOLOGY 28, 131-144.
SLAMA, K. (2000).
Extracardiac Versus Cardiac Haemocoelic Pulsations in Pupae of the
Mealworm (Tenebrio molitor L.). JOURNAL OF INSECT PHYSIOLOGY 46,
977-992. PASS, G. (2000). Accessory pulsatile organs: evolutionary
innovations in insects. ANNUAL REVIEW OF ENTOMOLOGY 45, 495-518.
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