ISSN:
1573-5117
Keywords:
Rotifera
;
Brachionus patulus
;
DDT
;
sublethal effects
;
life history parameters
;
demography
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The combined effects of sublethal levels of DDT (0, 15, 30, 45, and 60 µg·l−1) and food (Chlorella at 1 and 3 × 106 cells ml−1) on the demography of the rotifer Brachionus patulus were studied. The average lifespan, life expectancy, net reproductive rate (Ro) and intrinsic rate of increase (r) were significantly greater at the higher food level, but declined with increasing DDT concentration. A significant DDT food interaction was manifested in the toxicity-mitigating action of the higher food density at higher DDT levels. The r values were negative at DDT levels 30 µg · l−1 and above, only when food density was low. The effective DDT concentration at which a given parameter value was reduced to 50% of that in the controls (EC50) was lower at lower food levels for both survivorship and reproduction, and lower for reproduction than for survivorship at either food level.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00028292
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