蟑螂和一些昆蟲會周期性地停止呼吸,，這讓科學(xué)家們百思不得其解。一種假設(shè)認為,，通過關(guān)閉外骨骼上名為通氣孔的一個微小的呼吸瓣,，這些昆蟲能夠防止體內(nèi)的蒸發(fā)作用。
據(jù)美國《科學(xué)》雜志在線新聞報道,，研究人員最近對這一假設(shè)進行了測試,。他們在5周的時間里，將一種寵物蟑螂（Nauphoeta cinerea,，如上圖）放置在具有不同濕度的瓶子中,。與在悶熱的環(huán)境中相比,，在干燥瓶子中的蟑螂打開通氣孔的時間要比前者大約少40%。研究人員在9月份出版的《實驗生物學(xué)雜志》上報告了這一發(fā)現(xiàn),。很顯然,，這些昆蟲似乎能夠通過屏住呼吸來保持體內(nèi)的水分。（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of Experimental Biology 212, 2773-2780 (2009)doi: 10.1242/jeb.031310
Cockroaches breathe discontinuously to reduce respiratory water loss
Natalie G. Schimpf*, Philip G. D. Matthews, Robbie S. Wilson and Craig R. White
School of Biological Sciences, Faculty of Biological and Chemical Sciences, University of Queensland, Brisbane 4000, Australia
The reasons why many insects breathe discontinuously at rest are poorly understood and hotly debated. Three adaptive hypotheses attempt to explain the significance of these discontinuous gas exchange cycles (DGCs), whether it be to save water, to facilitate gas exchange in underground environments or to limit oxidative damage. Comparative studies favour the water saving hypothesis and mechanistic studies are equivocal but no study has examined the acclimation responses of adult insects chronically exposed to a range of respiratory environments. The present research is the first manipulative study of such chronic exposure to take a strong-inference approach to evaluating the competing hypotheses according to the explicit predictions stemming from them. Adult cockroaches (Nauphoeta cinerea) were chronically exposed to various treatments of different respiratory gas compositions (O2, CO2 and humidity) and the DGC responses were interpreted in light of the a priori predictions stemming from the competing hypotheses. Rates of mass loss during respirometry were also measured for animals acclimated to a range of humidity conditions. The results refute the hypotheses of oxidative damage and underground gas exchange, and provide evidence supporting the hypothesis that DGCs serve to reduce respiratory water loss: cockroaches exposed to low humidity conditions exchange respiratory gases for shorter durations during each DGC and showed lower rates of body mass loss during respirometry than cockroaches exposed to high humidity conditions.
