Anemia and Cutaneous Gas Exchange in Adult Aquatic Red-Spotted Newts, Notophthalmus viridescens viridescens

To investigate the role of hemoglobin in oxygen transport, the oxygen consumption rates at different temperatures of submerged normal and anemic newts were determined by a Micro-Winkler technique. Anemia was induced with intraperitoneal injections of 1-acetyl-2-phenylhydrazine dissolved in 10% ethanol. The normal newts were injected with comparable volumes of 10% ethanol. The mean hemoglobin concentration of the 30 anemic newts was 0.74 ? 1.0 g/100 ml of blood whereas that of 28 controls was 5.46 ? 1.99 g/100 ml. A two-way ANOVA (control-anemic vs. 5?, 14?, and 21?C) on the oxygen consumption values was significant (P < 0.05). A Newman-Keuls Multiple Comparison Test revealed that at 5? and 14? there was no significant difference in the oxygen consumption rates of the anemic and control newts, but that there was a significant increase in the rates with temperature. However, at 21?C the anemic newts' oxygen consumption rate (54.7 ,ul/gh) was significantly lower than the rate of the control newts (84.2 Al/g-h). Thus the presence of hemoglobin seems not to be necessary to transport oxygen at low temperatures in submerged Notophthalmus viridescens viridescens. Perhaps at lower temperatures, where the metabolic call for oxygen is decreased, sufficient oxygen may be physically dissolved in the blood plasma.