Project: Ecological Differentiation and Survivability of Tubifex tubifex Infested with Myxobolus cerebralis in the San Juan River Tailwater New Mexico

Primary Investigator: Colleen Caldwell
Project Summary: This research related T. tubifex lineage genetic variation to trophic conditions using cloned monocultures of lineage-specific T. tubifex from different habitats in the San Juan tailwater. Progeny of T. tubifex from the tailwater were used to establish two single-lineage laboratory stock cultures. Experimental tests of monocultures III and VI were replicated with infection challenges (0 and 500 spores/worm), water temperatures of 5, 17, and 27o C and diurnal photoperiods of 12:12, 14:10 and 16:8 (dark:light) to simulate a range of seasonal temperatures and photoperiods. Lineage III exhibited greater adult mortality than lineage VI regardless of treatment. Earlier field study findings were supported by the experimental study, as lineage VI exhibited a wide tolerance to environmental conditions and resistance to M. cerebralis infection whereas lineage III exhibited intolerance to variation and susceptibility to M. cerebralis infection up to 4%. The life histories of T. tubifex lineages and the effects that regulated flows may have on the species can be used to affect T. tubifex abundance and distribution in tailwater systems. These options may include altering regulated tailwater temperatures through different reservoir penstock releases at times when specific T. tubifex lineage communities are vulnerable, and providing scouring flow regimes to reduce organic loading and T. tubifex densities, both of which might reduce infection levels.
Funding Period: 2002-2003
Final Report: caldwell_02-03.pdf
Dataset(s) associated with this project:

Effects of Temperature, Photoperiod and Myxobolus cerebralis Infection on Growth, Reproduction and Survival of Tubifex tubifex Lineages