Combined Effects of Algal (Chlorella vulgaris) Food Level and Temperature on the Demography of Brachionus havanaensis (Rotifera): a Life Table Study

Abstract

We evaluated the combined effects of food (0.5 · 10 6 , 1.0 · 10 6 and 2.0 · 10 6 cells ml )1 of Chlorella vulgaris) and temperature (15, 20 and 25°C) on life history variables of B. havanaensis. Regardless of Chlorella density there was a steep fall in the survivorship of B. havanaensis at 25°C. Both food level and temperature affected the fecundity of B. havanaensis. At any given food level, rotifers cultured at 15°C showed extended but low offspring production. At 25°C, offspring production was elevated, the duration of egg laying reduced and the fecundity was higher during the latter part of the reproductive period. The effect of food level was generally additive, at any given temperature, and higher densities of Chlorella resulted in higher offspring production. Average lifespan, life expectancy at birth and generation time were 2-3 times longer at 15°C than at 25°C. At 20°C, these remained at intermediate levels. The shortest generation time (about 4 days) was observed at 25°C. Gross and net reproductive rates and the rate of population increase (r) increased with increasing temperature and generally, at any given temperature, higher algal food levels contributed to higher values in these variables. The r varied from 0.11 to 0.66. The survival patterns and lower rates of reproduction at 15°C suggest that the winter temperatures (10-15°C) prevailing in many waterbodies in Mexico City allow this species to sustain throughout the year under natural conditions.

Effect of Temperature on Fecundity, Life Span and Morphology of Long‐ and Short‐Spined Clones of Brachionus caudatus f. apsteini (Rotifera)

“…Offspring production may also be influenced by food level, e.g., higher density of Chlorella sp. increased offspring production of B. havanaensis (PAVÓN-MEZA et al, 2005).…”

“…In addition, the presence of predator (Asplanchna girodi) and low food levels can induce lorica and spine elongation in brachionid rotifers (B. quadridentatus: GILBERT, 2001; B. havanaensis: PAVÓN-MEZA et al, 2007). Temperature also has an effect on fecundity and life span of brachionid rotifers (see SNELL, 1986;GALKOVSKAYA, 1987;SARMA and RAO, 1991;PAVÓN-MEZA et al, 2005).…”

Differences in life history characteristics between two sibling species inBrachionus calycifloruscomplex from tropical shallow lakes

“…The responses of intrinsic rate of population growth to increasing temperatures were depended on rotifer species and algal food density. The intrinsic rates of population growth of B. havanaensis, B. rubens, B. urceolaris, B. forcatus and B. caudatus all significantly increased with temperature (Pavo´n-Meza et al, 2005;Hu et al, 2008;Tao et al, 2008). Similarly, the intrinsic rate of population growth of the sibling species LE9 in B. calyciflorus complex from Wuhu, China was the highest at 28 xC, at 13 and 18 xC it was the lowest.…”

Combined effects of temperature (level and oscillation) and cadmium concentration on the demography of Brachionus calyciflorus (Rotifera)

“…These results are largely based on zooplankton species cultured at constant temperatures. For example, it has been shown that an increase in temperature from 15 to 25°C, doubled the net reproductive rates of the rotifer B. havanaensis , but decreased the lifespan by about 60% . However, in certain waterbodies, water temperature may vary widely over a diel period: e.g., 5–25°C.…”