ROCKLAND — An exhibit featuring the work of four artists, Eric Hopkins, Kathleen Florance, Nils Obel and David Ridgway, will open with a reception from 5 to 7 p.m. Thursday, June 21, at Huston Tuttle and Gallery One, Main Street, Rockland. The show’s theme is fish, as interpreted by the participating artists. The show will run through July 24, and all work will be available for sale.