Physical Description

  • Long, slender body with long dorsal (back) fin from head almost to tail fin.
  • Dull-brown coloration with white square splotches.
  • Large head with blunt, rounded snout and prominent lips.
  • Males’ open mouth can be up to four times the size of it closed. Mouth opens into diamond shape, with red and yellow edges, blue inner lining and needle-like teeth.
  • Buggy eyes and fringe-like appendages on head (hence their name).
  • 9 to 12 inches long.


  • San Francisco, California to Baja California, Mexico.


  • Live in rocky reefs and nearby soft bottoms.
  • Live in burrows, narrow tubes of burrowing clams, in snail shells, and in marine debris (like empty bottles and cans).
  • Found at depths of 10-240 feet.


  • Female fringeheads lay about 3,000 eggs in a male’s burrow or tube and males fiercely protect the eggs until they hatch.
  • Female selection of a mate leads to fierce competition by males, where they display their open mouths at each other, often close enough that they can even touch.
  • The larger male displays dominance over the smaller, and the smaller male usually surrenders, leaving the area without an actual fight.
  • Spawning typically occurs from January to August.


  • Seen eating squid eggs.
  • Not well known what they eat in the wild, but thought that the males’ large mouths hinder eating.


Interesting Facts

  • Sarcastic fringeheads are a member of a group called tube blennies, because they live in tubes or burrows made by other animals.
  • Male sarcastic fringeheads compete with each other for females and territory by opening their very large mouths at each other. They attack each other, getting so near each other that the mouths can even touch. 
  • Extremely aggressive and fearless, they will charge anything that comes near their burrows, even divers.

Sources: Oceana; ScienceAlert; Aquarium of the Pacific

Photo: Kevin Lee