OPTIMAL CONDITIONS FOR REARING THE TADPOLE SHRIMP, TRIOPS LONGICAUDATUS (NOTOSTRACA, TRIOPSIDAE), A BIOLOGICAL-CONTROL AGENT AGAINST MOSQUITOS

Tadpole shrimp (TPS) were reared at 15, 20, 25, and 30 degrees C in th e laboratory. Size of TPS was temperature and age dependent with more rapid development at warmer temperatures. Survivorship was inversely r elated to rearing temperature. Mean age at death was 24.2, 19.2, 14.3, and 11.8 days at 15, 20, 25, and 30 degrees C, respectively. Rearing temperature (excluding 15 degrees C) did not affect lifetime fecundity , but larger TPS laid more eggs than smaller ones. Tadpole shrimp bega n ovipositing earlier at higher temperatures, and at a smaller size th an their counterparts in lower temperatures. Mean age at reproductive maturity was 18.8, 13.1, and 10.2 days and mean carapace length was 10 .8, 11.0, and 10.3 at 20, 25, and 30 degrees C, respectively. Embryoge nesis required a minimum of 3 days for completion. Hatching rates duri ng the first hydration decreased with increasing egg batch number prod uced by individuals, ranging from a mean of 74% for the first batch to 31% for the 5th batch. Cumulative hatching rates of eggs after 2 hydr ations were consistent across temperatures and egg batches (79 +/- 2%) .