1921
Volume 18, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645
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Abstract

Abstract

The fecundity of was measured as related to 1) food additives, 2) the lowering of the number of females per culture, 3) whether the snails were field or laboratory-reared, and 4) room-level and cycled light. The criterion was the number of young per female per month for 12 months. Petri-dish and clay-pot cultures were used when there were five or three females per culture, and five or two males. Food additives were powdered-rice cereal or powdered straw. When cycled light was used it was provided during an 8-hour period during the day by a 40-watt white-cool fluorescent bulb. The average output of young per female per month from field females in medium clay pots was greatly enhanced by adding enriched rice cereal (from 0.2 to 1.7). Greater productivity resulted when Petri-dish cultures were used and the number of females was decreased (production increasing from 5.7 to 6.3 young per female per month). The use of cycled light stepped up production to 7.8. Female mortality was less than one per culture per year in the best culture type. Laboratory-reared snails had excessive mortality and low fecundity, apparently related to poor nutrition during the growth phase.

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/content/journals/10.4269/ajtmh.1969.18.629
1969-07-01
2017-09-20
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