Ancylostoma duodenale and Necator americanus: effect of temperature on egg development and mortality.
The development and mortality of the eggs of Ancylostoma duodenale and Necator americanus in distilled water were monitored over a range of temperatures between 15 and 35 degrees C. Egg demography was examined within the context of a four-parameter mathematical model of development and mortality. Over the range of temperatures studied, egg mortality (mu) was an increasing exponential function of temperature (T) measured in degrees Celsius. A single model adequately described the mortality of both species (In [mu] = 0.41*T-6.87). The minimum time (tau) to hatching was consistently less for A. duodenale (In [1/tau] = -(0.79 + 53.05*[1/T]) than N. americanus (In [1/tau] = -(0.99 + 53.05*[1/T]]. The hatching rate (sigma when t greater than tau) was an increasing function of time and temperature in both cases, but the precise functional relationship was species specific.
Smith
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Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square 19348.
Schad
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GA
D000722:Ancylostoma / Q000254:growth & development*; D000818:Animals; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D009331:Necator / Q000254:growth & development*; D010063:Ovum / Q000254:growth & development*; D013696:Temperature