Reprinted with permission from Dive Training Magazine
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Swimming between colorful coral heads, a quick flicker close to the rubble and sand bottom catches your eye. You look down, but there is nothing. This definitely warrants a closer inspection so you settle down on the white sandy bottom to wait. Within a few seconds, a small yellow head with great bulging eyes pokes out of a hole. Slowly, a long, slender body with beautiful iridescent blue fins appears and dances in the water column just inches above the bottom. Soon an entire colony of these wonderful marine creatures is performing an underwater ballet above the sand.

The yellowhead jawfish is one of the most commonly sighted of the jawfish family. Named for its large mouth and jaws, this 2- to 3- inch fish has a yellowish head, tan to pearly body and bluish fins. Colonies of two to 10 are found in the sandy areas near coral outcrops at depths ranging from 10 to 160 feet. Their burrow-building methods and peculiar parenting habits make them a fascinating marine subject that can keep you entranced for an entire dive.

Architect and Homestead Builder
The jawfish can certainly be described as the busy beaver of the sea. From the surface, the yellowhead jawfish’s burrow looks simply like a small hole in the rubble, but it is actually a fine piece of underwater engineering work. The jawfish starts its burrow by digging a funnel-shaped pit about 8 inches in diameter and 6 inches deep. No shovel involved here – all the sand and rocks are carried in its mouth. Once the pit is complete, the jawfish, with the skill of a bricklayer, moves small rocks, shells and coral fragments into an intricate framework. The structure supports an entrance and tunnel leading from the surface to a lower bedchamber. This chamber, larger than the size of the jawfish, is lined with fine sand.

With the burrow built, the jawfish becomes a meticulous housekeeper. Throughout the day, especially towards the late afternoon, loose sand and rocks are carried in its jaws from the burrow to the doorway and expelled away from the entrance. Rocks around the opening are carefully adjusted to obtain a more suitable position. Often you will see a yellowhead jawfish zigzagging away from its burrow in search of the perfect rock addition for the entryway. Once it has been found, the jawfish quickly returns home.

As the daylight disappears, the jawfish retreats to its lower bedchamber and closes the front door by pulling a rock or shell over the entrance. The yellowhead jawfish, male and female, is extremely territorial (wouldn’t you be after spending so much time building your home) and will only allow its mate to enter its territory and visit its burrow.

The Romancing Male
The early morning or late afternoon (by yellowhead jawfish standards) is the best time for romance. During these periods, the amorous male tries to impress potential female partners by performing an “arch”. He positions his body horizontally in the water, bends his back, extends his fins and opens his mouth. Once engaged, the female happily follows the male into a honeymoon burrow built separately from each den. Here the couple will remain for a few seconds of privacy before reappearing and repeating the courtship ritual.

Once spawning has occurred, the male takes on the parenting responsibility of the clutch of eggs. The eggs hatch within five to seven days. Until then, he will incubate them in his mouth, often performing what is known as “churning.” The churning action involves spitting the eggs out of the mouth and then sucking them back in. This helps aerate the eggs and remove waste.

The age of the eggs can be determined from their color. When first laid, they are a yellowish, almost translucent, color and by the third day they have turned to a clutch of stunning silver spheres.

The easiest way to pick out a male with eggs is to look for a chipmunk-like expression on the face. You will have to be especially patient since a brooding male is much warier of divers approaching and will quickly duck tailfirst back into its burrow. It may take several minutes before it reappears.

Feeding Time
The majority of a yellowhead jawfish’s day is spent feeding. In fact, it is estimated that 90 percent of its daylight hours are spent picking zooplankton out of the water column. The feast consists primarily of copepods, shrimp larvae and other bits of floating microscopic food. Much like the grouper family, particles are ingested by quickly opening the mouth and creating a slight inrush of water and food.

Life is Not All Wonderful
Yellowhead jawfish tend to be somewhat wary and on approach of danger will head back to their burrow. The majority of time they will enter tail first but in a real emergency will dive headfirst and cover the burrow opening with a rock. Larger fish, such as the yellowtail snapper, produce a string flight response in the jawfish as do Nassau grouper, margate and southern stingray. Smaller, less threatening fish, such as the yellowhead wrasse and the slippery dick, may even cause the jawfish to respond aggressively by pursuing it with jaws spread or shaking its head while keeping its tail in the burrow opening. If the jawfish is surprised while burrow cleaning, it will often spit the sand and rocks in the direction of the intruder.

Sand tilefish are the feuding neighbors. The larger tilefish will often chase the jawfish into its burrow and then steal some rocks from the entranceway for use in its own mounds.

Getting Close
As mentioned, jawfish are somewhat wary of divers (huge, bubble-blowing monstrosities) and a quick or noisy advance will send them heading tail first into their burrows. The best approach is to settle in a sandy patch (watch where you set down, though) some 10 feet away from the burrow. Slowly creep, making as little movement as possible along the way. This stealthy approach may take you several minutes.

Gettiing the Perfect image
Jawfish are lovely animals to photograph. You will need a way to get close with a macro or close-up rig without disturbing the animal. Housed SLR cameras work the work the best although closeup kits using aiming lights instead of wire frames can work. Patience is the key to getting good pictures.

Vertical (portrait) formats work well if the jawfish stands on its tail in the water column or just comes out of its burrow. Horizontal (landscape) shots are great for capturing the cleaning of the burrow and the males clutching the eggs. Try timing the cleaning shot to capture the jawfish just spitting out the small rocks. There is quite a bit of luck involved here but if you try enough times you will get a great shot.

Remember to get down low for these shots. The darker background you get will make the jawfish stand out much better in the picture.

Pictures or no pictures, the jawfish is a delightfully animated creature to view underwater. Just remember to take your time, approach slowly and you will be treated to a great show.