We studied the embryonic use of material and energy during incubation and hatchling traits in the lacertid lizards Eremias argus, which were collected from a mountain population in Langyashan, Chuzhou, eastern China in April, 2005. We randomly selected one egg from eleven clutches, opened and separated them into shell and contents, the other eggs were incubated at naturally fluctuating temperature (varying from 14.0 to 37.0℃) using wet vermiculite as the incubation substrate, of which the moisture was kept at -12 kPa water potential. The incubation length of first clutches and second clutches averaged 37.5 d and 33.0 d, respectively. The wet mass of eggs increased for absorbing moisture while incubating, but no significant difference of the final wet mass was founded between first clutches and second clutches. Fluctuating temperature significantly affected Fat body dry mass, but it did not affect hatching success, sex ratio, snout-vent length, tail length, body wet mass, body dry mass, carcass dry mass and residual yolk dry mass of hatchlings. Fat body dry mass from higher fluctuating temperature was greater than did that from lower fluctuating temperature. Incubation temperature affected some norphological traits of hatchlings, with hatchlings from higher temperature having larger hindleg length and tympanum length than did those from lower temperature. Embryo from higher temperature used much calcium than did that from lower temperature. During incubation, approximately 57.5% of dry material, 27.8% of non-polar lipids and 47.4% of energy in the yolk of freshly laid egg was transferred to the hatchling. There was not significant clutch variation of embryonic use of material and energy and hatchling traits in Eremias argus.
