Abstract
The three species of tadpole shrimps (Branchiopoda: Triopsidae) were studied with regard to their life tables under experimentally controlled conditions with water at a temperature of 21-22°C. Many eggs hatched 2-3 days after submergence and the shrimps grew rapidly in repeating ecdysis. Triops granarius started oviposition 8 days, T. longicaudatus 10 days and T. cancriformis 16 days after hatching, respectively. The carapace length increased rapidly after egg hatching and steadily after the peak of oviposition. The survivorship curve declined steeply after the peak of oviposition. However, some individuals survived further even after oviposition had ceased and their carapace length increased steadily until their death. Almost all the individuals of T. longicaudatus oviposited daily and those of T. cancriformis at the peak period of oviposition, while in T. granarius, about 90% of the females oviposited. The total number of eggs deposited by each individual was largest in T. longicaudatus and smallest in T. granarius. For the purpose of biological control of paddy weeds T. granarius was expected to be most useful among the three species because of its rapid development and early oviposition.
