Stelzer, C. C.-P.. Max-Planck-Institut fuer Limnologie, stelzer@mpil-ploen.mpg.de
, . C.-P.. ,

 
SOMATIC GROWTH, EGG PRODUCTION, AND OVARY-SIZE DYNAMICS IN A PLANKTONIC ROTIFER
 
Somatic growth rates and egg production in planktonic rotifers have rarely been studied at the individual level. This talk presents a method to estimate these parameters, based on volumetric measurements of laboratory-cultured individuals of the rotifer Synchaeta pectinata. In my experiments I examined how different food concentrations affect somatic growth rates and the rate of ovary size increase (a measure for egg production) in both juvenile and adult rotifers. Somatic growth rates of juveniles were strongly affected by different food concentrations, whereas those of adults were generally very low, suggesting that nearly all production in adults ends up in reproduction. In animals that were raised at sufficiently high food concentrations, the relationship of ovary size vs. time showed a sawtooth pattern with sharp drops in ovary size after each egg laying. The rate of ovary size increase (ROI) between egg layings was dependent on food concentration and showed a hyperbolically saturated relationship. For all food concentrations that were tested, ROI and birth rates (as determined in accompanying life history experiments) were strongly correlated, suggesting that short-term measurements on ROI can possibly be used to predict long term birth rates in rotifers.
 
Day: Wednesday, Feb. 3
Time: 02:30 - 02:45pm
Location: Hilton of Santa Fe
 
Code: CS66WE0230H