, Volume 212, Issue 1, pp 169–179

Sex ratio variation in female-biased populations of Notostracans

  • Clay Sassaman
3. Genetics

DOI: 10.1007/BF00025998

Cite this article as:
Sassaman, C. Hydrobiologia (1991) 212: 169. doi:10.1007/BF00025998


Females from female-biased populations of the notostracan Triops newberryi produce viable eggs when reared in isolation. Clutches produced under such conditions exhibit sex-ratio polymorphism. One category of females (monogenics) produces only female offspring; the second category (amphigenics) produces clutches with a sex ratio of 3 females: 1 male. The relative proportions of the two categories of females varies significantly between populations and is correlated with population sex ratio. This correlation, and the pattern of offspring distribution in amphigenics, suggests that sex is determined by an autosomal Mendelian gene locus for which the male-determining allele is recessive. Limited pedigree analysis of lineages under selfing support the genetic model.

Key words

Triopssex ratiogeneticsselfing

Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • Clay Sassaman
    • 1
  1. 1.Department of BiologyUniversity of CaliforniaRiversideUSA