In 1898 it was suggested by David Starr Jordan and Barton Warren Evermann that the name referred to the "large anal papilla", but Girard did not mention this.

[7] In the United States it is preyed upon by the great blue heron (Ardea herodias), snowy egret (Egretta thula) and the willet (Tringa semipalmata).

[9] The diet of this species includes mainly crustaceans, especially amphipods, as well as fish eggs and larvae, polychaetes, and molluscs.

[7] Most of its food items are light-colored or clear, suggesting that these are easiest for the fish to see against the dark background of its habitat.

Their reproduction is oviparous with internal fertilization and spawning occurs in shallow coastal waters.

[7] Their mottled specks are green, greenish-black, greenish-brown and reddish covering their body as well as their fins.

[10] This fish has green blood plasma, the color caused by biliverdin tightly bound in protein complexes.