| Abstract: | Progesterone concentrations during pregnancy were measured in the plasma of the viviparous lizard (scincid) Tiliqua (Trachydosaurus) rugosa, using a radioimmunoassay specific for progesterone. The length of gestation in this Australian lizard was 140-170 days. The average number of young was 2.8 and the mean neonatal weight 58 g (maternal body weight 500-700 g). The mean concentration of progesterone was greatest (7.2 nmol/l) during the second trimester of pregnancy; mean values during the first and third trimesters, and in non-pregnant females, were 1.8, 0.9 and 0.2 nmol/l respectively. |
