Breathing tubes in action. This bug's "right-hand" breathing tube has been broken off -- it is a little less than half the length of the left-hand breathing tube. From observing this bug, I wonder whether the bug must have both breathing tubes drawing air simultaneously. That is, could the bug breathe only from the left-hand tube, with the shorter, right-hand tube beneath the surface of the water? If the bug must breathe through both tubes at once, then the shortened breathing tube would necessitate this bug's hanging out closer to the surface of the water than he ordinarily would have to; in other words, if the right-hand breathing tube were as long as the left-hand breathing tube, this bug might be able to repose at greater depth than he presently can. --Cat