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  • UC Riverside
  • College of Natural and Agricultural Sciences

Clay A. Sassaman


Emeritus Professor of Biology
Office: 3380 Spieth Hall
Phone (951) 827-5932


Ph.D., Stanford University, 1976

Research in my laboratory is primarily concerned with the population genetics and evolutionary biology of crustaceans, with special reference to branchiopod crustaceans living in temporary aquatic habitats.  Current focus is on genetic mechanisms of sex determination in fairy shrimps, tadpole shrimps and clam shrimps and on the role of mixed mating systems in influencing population-genetic attributes of locally isolated populations.  Research includes comparative morphology and biochemistry, genetic and life history studies, and taxonomy and systematics.  Since many of the species under study are either listed (or have been proposed for listing) as endangered, there is also a conservation biology component to the research program.

Dr.  Sassaman participates in both the Evolutionary Biology and the Physiology graduate tracks within the Department of Biology.

Some Representative Publications....

  • Sassaman, Clay; Fugate, Michael.  Gynandromorphism in Anostraca: Multiple Mechanisms of origin? Hydrobiologia, v.359, n.0, 1997.:163-169. 
  • Sassaman, Clay; Simovich, Marie A.; Fugate, Michael.  Reproductive isolation and genetic differentiation in North American species of Triops (Crustacea: Branchiopoda: Notostraca).  Hydrobiologia, v.359, n.0, 1997.:125-147. 
  • Shuster, Stephen M.; Sassaman, Clay.  Genetic interaction between male mating strategy and sex ratio in a marine isopod.  Nature (London), v.388, n.6640, 1997.:373-377. 
  • Sassaman, Clay.  Sex determination and evolution of unisexuality in the conchostraca.  Hydrobiologia, v.298, n.1-3, 1995.:45-65. 
  • Sassaman, Clay; Weeks, Stephen C..  The genetic mechanism of sex determination in the conchostracan shrimp Eulimnadia texana.  American Naturalist, v.141, n.2, 1993.:314-328. 
  • Otto, Sarah Perin; Sassaman, Clay; Feldman, Marcus W..  Evolution of sex determination in the conchostracan shrimp Eulimnadia texana.  American Naturalist, v.141, n.2, 1993.:329-337.

Recent Teaching....

  • Biology 5B, Introduction to Organismal Biology
  • Biology 151, Invertebrate Zoology