The possible influence of male worm age on the fecundity of Moniliformis moniliformis (Acanthocephala) in laboratory rats.

During the course of a primary infection of Moniliformis moniliformis in rats, involving an experimentally structured population of worms derived from infective doses of 10 male and 10 female cystacanths per rat, the fecundity of the female worms appeared to be influenced by the age of the males. The experimental design ensured that all the female worms were 35 days old when fecundity was assessed. On average, the number of eggs in females recovered from rats containing 28-day-old males was 20,930 +/- 2,143, that from rats containing 35-day-old males was 7,434 +/- 937, and that from 42-day-old males was 14,396 +/- 1,704; these values were found to be significantly different (least significant difference, P less than or equal to 0.01). The results suggest that the variable age of the worms would be likely to favor fecundity in naturally occurring infections.