What is the difference between muskrat, nutria and otter?

The muskrat is much smaller than the otter or nutria. They all lead a semi-aquatic life. Muskrat and nutria are mostly herbivores, and the otter is a carnivorous animal. The otter is from the weasel family, and the other two animals are rodents. The otter can dive well, its coat is rough. The muskrat has soft wool. The nutria is several times heavier than the muskrat, and much longer. The otter is more streamlined. Nutria does not build nests, while the other two dig nests near water. The otter can live in the sea, but the rest cannot.