The Culture Collection of Algae at Indiana University

IntroductionTwo experiments were conducted with a subtropical calanoid, Diaptomus dorsalis Marsh 1907, to determine the influence of food concentration and the volume of medium per copepod (one copepod in each of several containers of different volumes) on post-embryonic development rates, adult body size, clutch size, survivorship and sex ratio. Low concentrations of food (Chlamydomonas reinhardti) decreased development rates, body size, clutch size and survivorship; the sex ratio did not vary significantly from 1:1. Small container volumes had the same effects as low food concentrations, except that naupliar development time was not affected and survivorship showed greater variability. Because the copepod parameters exhibited maximum responses when food was abundant, even in the smallest container volume, it was concluded that container volume did not directly influence these parameters but exerted its effect through food availability.Larger life history stages were affected more than smaller life history stages by low food levels. In part, this was attributed to a laboratory artifact in which depletion of food by larger animals was greater than by smaller animals and, in part, to a real effect of low food concentration. A possible explanation of this real effect came from comparisons of these results to data from D. dorsalis fed phytoplankton from a Florida lake. The comparisons suggested that nauplii may be more efficient feeders on, or utilizers of, small food items such as Chlamydomonas.Numerous studies of natural zooplankton populations have correlated concentration of food with responses of various life history parameters. Although such studies have been useful in suggesting factors which may influence these parameters in nature, it has often been impossible to separate the effects of food from other factors, e.g., temperature, water quality and predation.For this reason, laboratory studies have been undertaken to elucidate the relationships between food concentration and zooplankton life history parameters. There have been many studies of the effects of food concentration on rotifers (e.g.

Section: Methodsmentioning

confidence: 99%

The influence of food concentration and container volume on life history parameters of Diaptomus dorsalis Marsh from subtropical Florida

Elmore

1982

“…87. Euglena, Chlorella, Haematococcus, and Botrydiosis were maintained on Proteose agar slants (Starr, 1964). Chlamydomonas was grown on Soil Extract agar (Starr,I964).…”

Section: Methodsmentioning

confidence: 99%

Observations on interactions between naturally-collected bacteria and several species of algae

Delucca

McCracken

1977

Interactions between a naturally-collected algal species and strains of bacteria with which it was closely associated were examined under controlled conditions. Three strains of bacteria, Pseudomonas, Xanthomonas and Flavobacterium, were isolated from Oscillatoria. These bacteria were grown in combination with axenic cultures of the Oscillatoria culture as well as with several additional algal species. Oscillatoria growth was stimulated by all of the bacteria, but other algal species varied in their response. Some were stimulated, but others were inhibited or unaffected by exposure to the bacterial strains. There were also observations indicating that some algae may be able to develop resistance to antagonistic bacteria. These data suggest that succession and dominance of individual algal species may be influenced by interactions with bacteria.

“…a common green alga, was used as the test organism. The nutrient-rich Bristol's solution (Starr 1964), together with the addition of minor Hydrobiologia 85, 6771 (1981). 0018-8158/81/0851-0067/$ 01.00 a Dr W. Junk Publishers, The Hague.…”

Section: Methodsmentioning

confidence: 99%

Metal interactions in algal toxicology: conventional versus in vivo tests

Wong

Beaverz

1981

Different studies on the toxicity of the same metals to algae have often shown divergent and sometimes contradictory results. The inconsistency of these findings was often attributed to environmental factors such as the degree of chelation, complexation and precipitation of metals. Conventionally, toxicity tests of metal mixtures were conducted by adding metals to algae growing in synthetic media. In our study, we examined the 'in vivo' toxic effects of metals by pretreating the algal cells with one metal, resuspendeding them in fresh medium, then exposing them to a second metal. The algal response showed marked differences between the conventional and the new approach. The conventional approach shows that the toxicity depends upon the complexes formed externally, whereas the in vivo approach shows that the toxicity probably depends upon the molecular transformation of the metals internally.