The eracliodes is found in some medieval encyclopedias. It frequents the water at edges of rivers, where it digs caves for itself in the earth.

Thomas of Cantimpré took his description from Pliny the Elder, who says these fish live near Heraclea, a region in northern Turkey on the shore of the Black Sea. Thomas appears to have based the name of the fish, eracliodes, on the name "Heraclea" (i.e. "the fish from Heraclea").