Growth and reproduction of three cladoceran species from a small wetland in the south‐eastern U.S.A.

Abstract

SUMMARY 1. Growth, reproduction and life‐history parameters were measured for three cladoceran species from a small south‐eastern wetland, U.S.A. Simocephalus serrulatus, Diaphanosoma brachyurum and Scapholeberis mucronata juveniles were reared at temperatures between 10 and 25 °C on natural food resources. 2. Growth rate increased with temperature and decreased with individual size for all three species. Maximum somatic growth rate was higher for Simocephalus (49–72% day−1) and Diaphanosoma (21–91% day−1) than for Scapholeberis (11–45% day−1). Multiple regression equations were developed which predict temperature‐ and mass‐specific growth rates for each species. 3. Scapholeberis egg production was positively related to temperature; however, maximum egg production occurred at intermediate temperatures for Simocephalus and Diaphanosoma. Mean cumulative egg production was higher for Scapholeberis (28–92 eggs per female) than for Simocephalus (18–25 eggs per female) and Diaphanosoma (1–41 eggs per female), and was related to differences in reproductive strategy and survival. 4. Survival was inversely related to temperature in most cases. For all three cladocerans, the intrinsic rate of increase (r) and net reproductive rate (R0) increased with temperature, whereas generation time (G) decreased. Greater egg production by Scapholeberis compared with the other two cladocerans was consistent with higher R0 values for Scapholeberis at any given temperature. Although r was very similar among species, G was typically longer for Scapholeberis than for Simocephalus and Diaphanosoma. 5. This analysis provides basic information about the population parameters of these coexisting wetland species, and the growth rate models can be applied to field data to determine production dynamics.

Growth and development time of subtropical Cladocera Diaphanosoma birgei Korinek, 1981 fed with different microalgal diets

“…Diaphanosoma generally reached a peak density in about 2 weeks (Lemke and Benke, 2003;Han et al, 2011), a trend also observed in the present study. When raised exclusively on H. pluvialis, D. birgei showed a lower growth than if they were cultured on mixed food which actually improved growth rates.…”

“…Diaphanosoma brachyurum had an r rate of 0.32 ind. day -1 at 25°C (Lemke and Benke, 2003); D. dubium had an r rate of 0.29 ind.day -1 at 29°C (Han et al, 2011) and the r rates of D. birgei in the current study were similar among the three diets (Ag; at temperature 24°C. In fact, they agreed with published ranges of other cladocerans species reared at similar temperatures and with various food conditions (Lemke and Benke, 2003;Ismail et al, 2011).…”

“…In the current study the average lifespan between 7 and 9-days was obtained with Ag and Ag + Hp diets, or rather, within the range reported for this species. In contrast to the mean lifespan of many temperate taxa of Diaphanosoma which was usually longer and varied between 2 and 4 weeks (Lemke and Benke, 2003), the lifespan of subtropical species was relatively shorter, or rather, 2 weeks (Sipaúba-Tavares and Bachion, 2002).…”

“…Bosmina, which reproduced more and earlier, had a lower survival rate than those reproducing later and slower. Some researchers have reported that animals which grow faster and put more energy in reproduction tended to have a lower life expectancy (Lemke and Benke, 2003;Sarma et al, 2005;Ismail et al, 2011). Their argument emphasised the advantage of assessing life history over the lifespan of the individual.…”

“…Several studies have shown that cladoceran have a higher nutritional value than other live food sources for many fish larvae, because their broad size range, high digestibility and high food value allow better grow and development than other live diets (Sipaúba-Tavares and Bachion, 2002;Lemke and Benke, 2003;Sarma et al, 2005;Ismail, et al, 2011).…”