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Gas exchange patterns of Pterostichus niger (Carabidae) in dry and moist air
Author(s) -
KIVIMÄGI IRJA,
KUUSIK AARE,
JÕGAR KATRIN,
PLOOMI ANGELA,
WILLIAMS INGRID H.,
METSPALU LUULE,
HIIESAAR KÜLLI,
SIBUL IVAR,
MÄND MARIKA,
LUIK ANNE
Publication year - 2011
Publication title -
physiological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 57
eISSN - 1365-3032
pISSN - 0307-6962
DOI - 10.1111/j.1365-3032.2010.00768.x
Subject(s) - biology , respirometry , relative humidity , open air , zoology , ecology , thermodynamics , physics , architectural engineering , biochemistry , engineering
Gas exchange patterns of adult male Pterostichus niger Schaller after hydration (i.e. given access to food and water) are compared in dry air [5–7% relative humidity (RH)] and moist air (90–97% RH) by means of flow‐through CO 2 respirometry combined with infrared probe actography. Of thirty beetles examined, slightly more than 50% showed continuous gas exchange and are not considered further. Of the remaining beetles, the majority (approximately 71%) display a pattern of cyclic gas exchange in both dry and moist air (i.e. CO 2 gas is released in bursts, with a low level of CO 2 release during the interburst periods). A minority of the beetles (four out of 30) are found to exhibit discontinuous gas exchange in both dry and moist air; this is characterized by three clearly separated states of the spiracles: closed (C), flutter (F) and open (O) phases. The pattern of cyclic gas exchange is associated with weak abdominal pulsations. After switching from moist to dry air, a small modulation of the discontinuous gas exchange cycles (maximum mean CO 2 production rate) occurs, providing no clear support for the hygric theory of discontinuous gas exchange in this species (i.e. that it serves to restrict respiratory water loss).