The one distinguishing feature of Nocardia is its true branching. Once the true branching is identified under the microscope, doing a Gram stain is nothing more than a confirmatory step. Nocardia is Gram positive. That is, it stains purple or dark blue as opposed to red. The phylum Rotifera is known for its highly interesting organisms.
Rotifers are complex organisms with various types of organs and structures.
The photos you have just seen are but a small portion of the wastewater organisms database and its capabilities. Take for example the search possibilities. You might want to search for filament 0041. You would just type in 0041 into a search dialog box. Along with the photos and video a caption would also be found along with other technical information like width and length.