A HANDY METHOD FOR MEASURING MEIOBENTHIC RESPIRATION

Our current understanding of meiofaunal respiration rates, and especia lly of the way they are influenced by changing abiotic factors, is sti ll far from complete. Meiofaunal respiration is traditionally measured using Cartesian divers or related manometric techniques, but these ar e extremely time-consuming and labour-consuming. We have evaluated the use of the Strathkelvin polarographic electrode model 1302 and the O- 2 monitor model 781 in determining the O-2 consumption of meiofaunal a nimals. Respiration rates obtained in this way of the terrestrial nema tode Caenorhabditis elegans compared well with results obtained from C artesian diver respirometry. Experiments with 3 estuarine nematode spe cies show that 5% accuracy levels are obtained with respiration rates down to 200 nl O-2 h(-1). This involves the use of a few tens to a few hundred individuals, depending on the size and the respiratory activi ty of the animals. Several practical problems that relate to accurate determinations of O-2 consumption are discussed. It is concluded that short-term measurements and fairly easy procedures make polarographic O-2 electrodes an interesting and reliable tool for routine measuremen ts of meiofaunal community respiration and of the influence of abiotic factors on meiofaunal aerobic metabolism.