Since I first set eyes on a wild specimen while scuba diving in the Florida Keys, I’ve been enamored with the yellowhead, a.k.a. pearly, jawfish (Opistognathus aurifrons). Though not the most chromatically gifted fish in the sea, this burrowing beauty is, nonetheless, packed with piscine personality and makes an excellent choice for the saltwater aquarium.
O. aurifrons has a slender, almost eel-like body and reaches a maximum length of approximately four inches. As its common name suggests, the head is light yellow while the rest of the body is a lovely pearlescent color with a faint hint of blue. Specimens are typically observed hovering in a nearly vertical orientation just above their burrows, which they construct in the sand at the base of the reef and can retreat to with lightning speed when spooked.
Being a relatively small, burrowing species, the yellowhead jawfish does not require an especially large aquarium. A 30-gallon tank will more than suffice provided enough open bottom real estate is available.
The substrate must be at least four inches deep to accommodate this species’ burrowing behavior, and it should include material of varying grain sizes as well as larger rubble pieces that your jawfish can use to stabilize its home. Burrows constructed in substrate consisting entirely of fine-grain sand are likely to collapse (on top of your jawfish!).
Any fishes that share your yellowhead jawfish’s tank must be relatively small, peaceful, and sedate. Large or highly energetic species constantly swooping overhead will keep your jawfish perpetually concealed in its burrow, so all you’ll ever see is a pair of bulging eyes glancing nervously about.
Interestingly, O. aurifrons is one of a limited number of marine species that can be kept more than one to a tank. Just be sure your system provides enough open substrate to allow at least a foot of spacing between each burrow.
The yellowhead jawfish’s natural diet consists primarily of zooplankton that drifts close to its burrow. In captivity, it will accept a wide range of fare. Items such as mysis shrimp, plankton, chopped clams or shrimp, and other small, meaty foods will be accepted with gusto. Your specimen may even learn to accept dry pellets and flakes.
It’s important to ensure that any foods you offer actually drift within reach of your jawfish, however, as this species prefers to dine fairly close to home. Target feeding (e.g., with a turkey baster) just “upstream” from a specimen may be necessary to ensure it’s getting enough to eat.
Taking a flying leap
If you’ve heard that the yellowhead jawfish is a good jumper, you’ve not been misinformed! This species is a true acrobat! Once while giving a specimen a freshwater dip, I watched in disbelief as it “tail walked” like a dolphin across the water surface and flipped right out of the container. Fortunately, I was right there on hand to pick it up and return it. Needless to say, a good tank cover is a must if you plan to keep this species.