caa a22 4500 465826490 CHVBK 20180323112150.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00302598 doi (NATIONALLICENCE)springer-10.1007/BF00302598 The effect of incubation media on the water exchange of snapping turtle ( Chelydra serpentina ) eggs and hatchlings [Elektronische Daten] [Yeong-Choy Kam, Ralph Ackerman] Summary: The effect of two different incubation media, sand and vermiculite, on the water exchange of eggs and the mass of hatchlings of snapping turtles (Chelydra serpentina) was assessed. The eggs were incubated fully buried in either sand or vermiculite at 30 °C and egg mass was measured periodically throughout incubation. The wet and dry masses of each hatchling and its residual yolk were measured at the end of incubation. The media had similar water potentials (Ψ) but their thermal conductivities differed 2.8-fold. The eggs experienced a net water gain during incubation. The rates of water uptake between treatments were not statistically different throught the first 36 days of incubation but were statistically different thereafter, with eggs incubating in sand taking up water at about twice the rate of eggs incubating in vermiculite. Hatchling masses were similar to both media but hatchling water contents were significantly different. Hatchlings incubated in sand had lower water contents than hatchlings incubated in vermiculite even though the eggs in sand took up more water. Hatchling mass was correlated with egg water exchange for eggs incubated in vermiculite but not for eggs incubated in sand. The difference in egg water exchange in the two media appears to be attributable to differences in the thermal conductivity of the media. The presence of such a thermal effect supports the hypothesis that the eggs exchanged water with the media as water vapor. Egg water exchange was limited by the shell and shell membranes and not by the media. The shell and shell membranes appear to present an effective barrier to water uptake. Springer-Verlag, 1990 Turtle nationallicence Egg nationallicence Water exchange nationallicence Medium thermal conductivity nationallicence M H 2 O : water flux (cm3·day-1) nationallicence L p : hydraulic conductivity (cm·day-1·kPa-1) nationallicence A : shell area (cm2) nationallicence A p : pore area (cm2) nationallicence l : shell thickness (cm) nationallicence r : pore radius (cm) nationallicence η : viscosity (kPa·day) nationallicence P EH 2 O : egg water potential (kPa) nationallicence P AH 2 O : medium water potential (kPa) nationallicence G H 2 O : water vapor conductance (cm3·day-1·kPa-1) nationallicence D H 2 O : diffusion coefficient (cm2·day-1) nationallicence R : gas constant (cm3·kPa·K-1·cm-3) nationallicence T : temperature (K) nationallicence P EH 2 O : egg water vapor pressure (kPa) nationallicence P AH 2 O : medium water vapor pressure (kPa) nationallicence d : egg diameter nationallicence K : soil hydraulic conductivity (cm2·day-1·kPa-1) nationallicence DHM : hatchling dry mass nationallicence WHM : hatchiling wet mass nationallicence WU : water uptake nationallicence IM : initial egg mass nationallicence Kam Yeong-Choy Department of Zoology, Iowa State University, 50011, Ames, IA, USA aut Ackerman Ralph Department of Zoology, Iowa State University, 50011, Ames, IA, USA aut Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 317-324 0174-1578 160:3<317 1990 160 360 https://doi.org/10.1007/BF00302598 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00302598 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kam Yeong-Choy Department of Zoology, Iowa State University, 50011, Ames, IA, USA aut NATIONALLICENCE 700 1- Ackerman Ralph Department of Zoology, Iowa State University, 50011, Ames, IA, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 317-324 0174-1578 160:3<317 1990 160 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer