Life history characteristics of three types of females in Brachionus calyciflorus Pallas (Rotifera) fed different algae

This study describes the life history characteristics of amictic, unfertili zed mictic and fertilized mictic females of the rotifer Brachionus calycifl orus cultured individually on two different algae at 0.1 mg ml(-1) food con centration and 27 degreesC. The duration of the juvenile period of amictic females was significantly shorter on Chlorella pyrenoidosa Chick than on Sc enedesmus obliquus Kutz or both algae together. The duration of the juvenil e period of unfertilized mictic females was significantly longer, and the n umber of eggs produced by amictic females was significantly larger on Chlor ella pyrenoidosa than on S. obliquus. When fed the same type of alga, the d uration of the juvenile period of the fertilized mictic females was the lon gest among the three types of females, and the durations of the reproductiv e period of the amictic females and the post-reproductive period of the fer tilized mictic females were longer than, or equal to those of the other two types of females, respectively. The number of eggs produced by an unfertil ized mictic female was the largest among the three types of females, and th at of amictic females was larger than or equal to that of fertilized mictic females, depending on the type of diet.