Yellowhead Jawfish Care Guide

Opisognathus aurifrons

DifficultyMedium
Minimum Tank Size30 Gallons
DietCarnivore
Water Parameters72-78 F, pH 8-8.4, Salinity 1.020-1.025
AggressionPeaceful
Size4"

The Yellowhead Jawfish, sometimes called the pearly jawfish, is a small carnivore who creates a small cavern underneath the sand bed. They fortify their new burrow with larger pieces of rock, sand and miscellaneous debris, creating a solid tunnel for their home.

They are able to dig these homes thanks to their large jaws, which can scoop and move large portions of sand.

The Home Of The Jaw Fish

To properly house these fish you must have a large, clear space in the tank, preferably in the center, where the jawfish can create a cave. Additionally they will need a sandbed substrate, along with small rocks, rubble or crushed coral. These will be the building bricks of the jawfishes new home. I highly recommend crushed coral, as it is the easiest to obtain without spending a whole lot.

Keep a close eye when the jawfish is first building their home, as their digging can easily cause rock slides. Once their burrow is complete this should no longer be an issue.

The deep sandbed required is the main topic here. The Yellowhead Jawfish requires no less than 5″ of sand. This can create plenty of toxic air traps, meaning your filtration, flow and sand sifting become twice as essential as the normal tank.

Diet & Feeding

The Yellowhead Jawfish is easy to feed, as they will accept prepared foods without hesitation. There is however a different issue to face when feeding

When the Jawfish is not comfortable with their environment, they will be unlikely to leave the burrow, sitting inside with their head poking out like an eel. Comfortable jawfish will dart out of their burrow for feeding time, have their fill and then return to business as usual. Uncomfortable jawfish, on the other hand, will need the food to be delivered to their home.

The Yellowhead Jawfish will gladly accept frozen foods and can be trained to eat pellets with relative ease. Simply introduce pellets along with the frozen foods. They will pick on the food, as they understand you are feeding them. After this they will either ignore the food for now or eat it. Continue doing this, scooping out any excess food to prevent an algae bloom.

Picky Eaters: We have all been here. Our fish should be eating. The tank is stress free, there are no predators and the fish is happy in their home. Yet for some reason the fish completely avoids our foods. For jawfish there is an easy fix.

Frozen table shrimp

While this may seem silly on its own, there is a lot of reasoning behind it. First off the jawfish loves to eat small crustaceans such as copepods and amphipods. These however are hard to keep in stock in the tank. To replicate them you can simply freeze a table shrimp, without its shell, and grind it with a grater. This will produce small shrimp pieces which are close enough to copepods for the jawfish to attack. Using this method you will easily be able to get any picky jawfish back on track to a healthy diet.

Behavior & Aggression

The Yellowhead Jawfish is a pushover when it comes to other fish. They are not suited to tanks with any aggressive tank mates and are easy targets as they create a burrow from which they cannot escape. Be wary of any opportunistic feeders, such as emerald crabs who can easily corner the jawfish.

The Yellowhead Jawfish is not typically aggressive towards its own species, however territorial disputes can occur if the tank is too small. I would recommend at least 30 gallons per jawfish, with 3-4 jawfish being the limit on how many you should have. Keeping additional jawfish is typically an attempt to form a mated pair, so more than a few should not be necessary.

When the jawfish is happy and free of predators and other stressors you can expect them to swim around the tank a little bit and spend the rest of their time peeking out of their burrow and watching other fish. Their faces are highly expressive and they will often interact with any passing tank mates.

Breeding & Sexing

The Yellowhead Jawfish can be bred in captivity, with the Yellowhead Jawfish being the easiest jawfish to breed. However the survival rate of their fry in the home aquarium is fairly low. First off you will need to get a pair.

Jawfish are very difficult to sex, with the most reliable method being the shape of their head. Those with more pointy heads and smaller bodies are typically female while the larger, flat large headed jawfish are much more likely to be male. Additionally females will frequently have a more rounded abdomen than their male counterparts.

To begin the breeding process you will need to ensure a few things.

First the jawfish must be given adequate room. This means a large tank with a fair amount of room around their burrows. This is more easily obtained using a breeder than a standard fish tank.

Second you will need to keep the jawfish well fed and stress free. When the male is stressed he will not call out to the female for mating. Likewise a stressed female will ignore any mating rituals started by the male.

Finally you will need to either remove any fry hunting fish or remove the fry once they hatch. This means having a prepared isolation tank and transportation method. Containers work far better than nets for fry, as nets can apply more force than the fry can handle.

To start mating the male will swim high in the tank and begin flaring his gills and waving his body. Once the female notices they will meet with the male and follow him around the tank, often returning to a burrow where she will release her eggs.

Once the eggs have been laid and fertilized the male will hold the eggs for several days in his mouth, sometimes leaving them in the burrow to feed. The less experience males will often lose eggs in this process, meaning multiple breedings must be done for a successful spawning. Those even less experienced may even eat these eggs, meaning a lot more spawning will be needed for successful spawning.

Jawfish will only spawn in the middle of their life span. Those too young or too old will not attempt to spawn, with the age of two being the average time where spawning no longer occurs. This is frighteningly early for those looking to keep a bloodline of jawfish running in their tank. Likewise those with well established jawfish may have missed their chance to breed the fish.

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