°C. These H. japonica were shown to survive at -30 °C for up to 120 days. Other frog species, at such temperatures, will accumulate ice, a phenomenon that proves lethal. This accumulation of ice was not observed in H. japonica. During the exposure to cold, H. japonica seems to produce glycerol. This production of glycerol increases as temperature decreases. It is thought that this glycerol production plays a role in the cold-resistance of H. japonica. However, other frog species have similar glycerol production, but do not have cold resistance to the extent of H. japonica. Thus, the biochemical mechanism for the cold resistance of H. japonica is yet to be fully determined. Bone mineral density H. japonica have also been studied in order to determine the predictive ability of bone mineral density on the physiological well-being of frogs. Frogs with observed bone fractures on CT scan did not have significantly different bone mineral densities in comparison to healthy frogs. Thus, these frogs were unlikely to suffer from bone mineral diseases, and their fractures are more likely attributed to trauma-related injury. Bone mineral density was strongly correlated to snout-vent length in H. japonica. Bone mineral density was not observed to be significantly different between males and females. This lack of difference can be attributed to the similar eating habits of both male and female H. japonica. H. japonica were observed to have fractures distributed similarly in both their forelimbs and hindlimbs. Bone mineral density was able to effectively evaluate food status and physiological condition in H. japonica. This finding offers a mechanism for determination of food status for anuran populations. Anuran vasotocin and mesotocin receptors H. japonica has been used to determine the effects of anuran vasotocin (VT) and mesotocin (MT) receptors. VT, coupled to cyclic AMP, has antidiuretic effects in most amphibians. MT, which acts through the inositol/calcium signaling pathway induces diuretic effects in most amphibians. It was discovered that H. japonica contains both VT and MT receptors and that these receptors are differentially expressed in the body of the frog. VT receptors are localized to the pelvic patch of skin, whereas MT receptors are found in the fat body of the frog. Both MT and CT receptors are found in the brain, heart, kidney, and urinary bladder. This differential distribution of MT and VT receptors affects the cutaneous water absorption of H. japonica. Conservation The IUCN determined that the