Fish of the week - Opistognathus aurifrons (yellowhead jawfish)


Sir Brian The Lenient
Staff member
RC Mod
Opistognathus aurifrons Yellowhead jawfish

Commonly known as the yellowhead jawfish or yellow headed pearly jawfish, these fish are native to the tropical Western Atlantic. They live in sandy areas of the reef, normally surrounded by coral rubble. These fish are fascinating architects, and construct caves in which they will reside. In the home aquarium they will normally only show their head poking out of their burrow, and will rarely show much else. It is a treat when they do come out, so the aquarist can view its beautiful pearly white and blue body. It usually only comes out to feed, and can return to its burrow at the blink of an eye.

Due to its need to burrow and construct a home, it should be kept in a tank with a mixed substrate of fine, soft sand and coral rubble. They normally fare better with docile tankmates, since more aggressive fish may prevent them from venturing from their burrow to feed. More than one can be kept in a large tank, and in fact they may form groups in one area of the tank. In the tank, they are very comical
inhabitants as they dance in and out of their burrow.

The jawfish can reach up to 4 inches or so. They will readily spawn in captivity, and the male will incubate the eggs in his mouth. He will "swish" the eggs around in his mouth to oxygenate them and also as a means of protection.

As mentioned above, these fish are timid feeders, and may need to be directly fed with food placed near their burrow. They will accept various prepared and frozen foods designed for carnivores. Small pieces of mussel, mysid shrimp, or other meaty flesh may need to be offered in the beginning to help acclimate the fish to prepared foods.

These fish are reef safe (typically). As flesh eaters, larger specimens may be a danger to smaller shrimp,
but this would not be the general rule.
Two other items to mention:

1) Substrate needs to be at least 4 inches deep

2) These fish are jumpers, usually lost the first
night. They will settle down when they get their burrow
First I would like to tell you that I really enjoy your Fish of the Week post.

Are these fish detrimental to the fauna of the sandbed??
Hi Candy

Thanks for your comments. I don't believe that the jawfish would be any risk. Copepods, worms, etc wouldn't be a main part of their diet, and in any case with their sedentary lifestyle the jawfish wouldn't stray far enough from their hole to impact any population of fauna other than those right next to them. These fish will basically just eat the food that drift by their hole (if it suits their tastes :) )


I've had one going on 4 years. You really don't need 4" of substrate. If you have a few rocks it an tunnel under and 2" of substrate with some small rocks and pebbles thrown in the fish will do fine. The jumper stuff is accurate. One thing I'd like to mention, if you ever remove the fish from your tank for some reason, short term (like for cleaning, etc), it's a good idea to put the jawfish in its own container. The jawfish outside of its hole is completely defenceless. I had one die in a holding bucket in just a few minutes. I don't know if it had a heartattack or was attacked by another fish (had already had the fish for 1 year at the time).

- Greg Hiller
Regarding the depth of substrate, I have no personal experience, but this was the depth recommended by Scott Michael, Morgan Lidster and others in their various writings.

Will they undermine the live rock with their excavations, or do they stick to one spot?

I've had a pearly jawfish for just about a year now.6" of substrate. He was doing great, had a nice burrow under a piece of live rock.Every time I opened the top to feed he would be the first to look for the food. Last week he decided that he didn't want to live in the tank any longer.He got into the overflow box ,sucked through the u tube,through the plumbing, into the sump. I kept trying to put him back in the tank ,but he would just swim to the top over to the over flow back to the sump. Finally got him to stay in the main tank ,for a week, but,he did it again, but this time he got stuck in the return plumbing to the sump,lots of water over the carpet ( 15 gallons ) wife's going to shoot me,and jawfish has new home!!!!
Agu, maybe someone with personal experience will step in, but I know that Inland Aquatics has several jawfish in a big display tank, and they all make their holes out in the open sandbed away from the reef structure.

The PVC trick seems to have been forgotten.
Take 6-8" of 3/4" PVC, cap it on one end and drill that end full of 1/4" holes. Bury, leaving about 1/8" sticking out. Instant jawfish home.
They are usually scaired of their own shadows and anything else for that matter. If they are not secure they will jump out.
We have 10 living happily in a 250 gal.