, Volume 212, Issue 1, pp 137–143

Factors affecting contributions of the tadpole shrimp, Lepidurus packardi, to its oversummering egg reserves

  • J. S. B. Ahl
2. Ecology

DOI: 10.1007/BF00025995

Cite this article as:
Ahl, J.S.B. Hydrobiologia (1991) 212: 137. doi:10.1007/BF00025995


The phenology and reproductive biology of the tadpole shrimp, Lepidurus packardi, which inhabits temporary annual pools in northern California, U.S.A., were investigated to identify factors affecting its contributions to its egg reserves that oversummer in the dried pond sediments. Field observations throughout 2 seasons revealed the nearly continuous presence of juveniles, indicating multiple generations, and a predominance of males during the mid to late stages of the pond. Observation of the first oviposition, and dissections revealed that sexual maturation occurred in shrimp 10–12 mm carapace length. Fecundity increased with size, but was drastically reduced in parasitized individuals. Metacercariae of an echinostome fluke caused parasitic castration in 53% of the population by mid-season. In the laboratory, oversummered eggs collected from dried pond sediments hatched within 17 days, when incubated at 10 °C. Eggs laid in the laboratory hatched within 25 days at 10 °C, without prior dehydration, but hatching was reduced at higher temperatures.

Key words

Lepidurus packarditadpole shrimpparasitic castrationphenologyreproductive biology

Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • J. S. B. Ahl
    • 1
  1. 1.Department of Biological SciencesCalifornia State UniversityChico
  2. 2.Department of BiologySt. Ambrose UniversityDavenportUSA