The hair of nutria has long parts of fur which are excellent, for example, for long poles od dry caddis. This fur is also very well suited to the wings and tails of the streamers.
The undercoat is excellent as dubbing on nymph and wet fly bodies - it has very similar properties as beaver fur. The natural (uncoloured and non-dyed) undercoat also has a good float options, so it fits perfectly with the bodies of dry flies!