In this study we hypothesized that Grammostola rosea Walckenaer 1837, an active predator of large size which depends entirely on its two paired book lungs, has a low energy strategy based on large respiratory surface area and a thin air-hemolymph barrier.
Three of the spiders ([M.sub.b] = 13.4 [+ or -] 2.65 g) were sacrificed, and their book lungs were carefully extracted and immersed in 2.3% glutaraldehyde in phosphate buffer at 4[degrees]C for a minimum of 2 h.
Pretreatment with 5% TCA at 90[degrees]C to extract DNA, followed by staining in fast green at pH 8.1 resulted in coloration only in nuclei of the
book lung and other somatic tissues adjacent to the testis, but the sperm remained unstained (Table 1, Fig.
