Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 4043

William A. Muller and John J. Lee; Biological Interactions and the Realized Niche of Euplotes vannus from the Salt Marsh Aufwuchs. J.Protozool. 24(4):523-527, 1977

Reprint

In File

Notes

Euplotes vannus, a hypotrich ciliate, grows well over broad ranges of temperature and salinity. It requires higher densities of food (>1x10E4 cells/ml) for rapid reproduction than do the other herbivores, the foraminiferan Allogromia laticollaris (>1x10E2 cells/ml), and the nematode Chromadorina germanica (>/=1x10E3 cells/ml), to which it was compared. If food levels were initially very high (~1x10E8 cells/ml) the ciliates reproduced rapidly and consumed the algae faster than it could reproduce. Some balance between the algae and the ciliates was achieved at initial algal concentrations of ~1x10E5 cells/ml. In microcosm experiments at 25 degrees C with equal numbers of C. germanica and A. laticollaris, E. vannus proved to be a very poor competitor; reaching only 20% of control levels when grow with C. germanica and only 13% when cultured with A. laticollaris. It was a better competitor in 2-species microcosms, at lower temperatures, and when its ratio to the other species was initially higher. The experimental evidence suggests that E. vannus is best adapted to being a migrating initial colonizer of fresh algal blooms.