SEDL / STP / STP921-EB / STP29038S

Factors Affecting the Culture of Daphnia Magna

Lee, CM
Scientist, assistant scientist, and scientist, Unilever Research Laboratory, Bebington, Wirral, Merseyside, UK L63

Turner, CA
Scientist, assistant scientist, and scientist, Unilever Research Laboratory, Bebington, Wirral, Merseyside, UK L63

Huntington, E
Scientist, assistant scientist, and scientist, Unilever Research Laboratory, Bebington, Wirral, Merseyside, UK L63

Pages: 12    Published: Jan 1986

Download this paper for $25 PDF (184K)          View License Agreement
Abstract

A factorial design was used to determine the individual and combined effects of light intensity, photoperiod, temperature, food, and feeding regime on the survival and production of Daphnia magna. Changes in light intensity between 150 and 1000 lx, in photoperiod between 16 and 24 h, and in temperature between 18 and 23°C will not affect survival. There is however a strong light times temperature times food interaction that can influence juvenile production. Using a higher light intensity when the food level was low improved productivity. The individual effects of increasing temperature and photoperiod were trivial. Low juvenile production was found when a low food level of 1.5 × 10⁵ cells/mL Chlorella vulgaris was coupled with a low light intensity of 150 lx and a temperature of 23°C. Feeding C. vulgaris grown in vitamin-enriched medium improved juvenile production only when the food level was high and appeared to have a negative effect when food quantity was inadequate. Food was provided as C. vulgaris alone or mixed with yeast cells and at various cell numbers of both. Juvenile production that would meet current criteria for 21-day life cycle tests was achieved with 7.5 × 10⁵ cells/mL vitamin-enriched C. vulgaris both with and without yeast at 1.5 to 2.5 × 10⁶ cells/mL under a light intensity of 1000 lx and a photoperiod of 16 h at 18°C.