During the 1940's and 1950's, Calder created a small number of hanging mobiles in the shape of fish. Numbering about a dozen, the Fish are composed of painted metal rod to create their silhouettes and a net of wire strung inside this framework to create the scales. Fragments of glass, ceramic shards and found objects are suspended from the wires and catch both changing light and air motion as the mobile turns, to create the sense of a colorful fish in motion.

These delightful mobiles were usually created as commissions or as gifts to Calder's friends. The group of original owners included the artist Rufino Tamayo, and Calder's early dealers Curt Valentin and Klaus Perls. Both the Whitney Museum and the Hirshhorn Museum collections now include Fish mobiles.

The Paepcke Estate Fish is the only one from this small group with a human face as well as human hands at either end of the fins, which are suspended perpendicularly from the center of the body. Calder and Mr. Paepcke were friends and the family recognized his features in the long-nosed profile of their mobile.