Six juvenile Neoceratodus of convenient size for respirometry (27-51 g) were available for study. Fish of this size are very rarely taken and the opportunity was used to examine the ability of Neoceratodus to undergo metabolic acclimation. Metabolic rate-temperature curves were constructed for fish with cold (18�C) and warm (25�C) thermal histories, using oxygen consumption as a measure of the rate of metabolism. The Q10 of fish with warm history (Q10 = 2.42) was higher than that for fish with cold history (Q10 = 1.55), and it was seen that there was partial thermal acclimation over the range investigated.