Yes, I've kept the northern sculpin.
They are interesting, although fairly reclusive and highly predatory. While snorkeling and collecting fish in New England, I find it interesting how the color and patterns of the sculpin I find vary depending on what sort of environment they are inhabiting. For example, ones staying toward sandy areas with only some small rocks tend to be very light/white in color. Those around the rocky areas are usually a mottled brown, and those inhabiting the red seaweed covered rock areas are usually banded with maroon/brown and white or grey.