Black Cap Jawfish

Black Cap Jawfish (Opistognathus randalli) is a semi-aggressive species that is reef-safe with caution, admired for its striking black cap coloration on the head, elongated body, large mouth adapted for burrowing, and unique jaw protrusion behavior. Males typically are larger, exhibit more vivid coloration on the head, and actively defend their burrows, while females/juveniles are smaller, less brightly colored, and more shy. They reach about 4 to 5 inches and should be housed in aquariums of at least 30 gallons.

Provide a deep sandbed for burrowing, plenty of live rock for structure and hiding spots, moderate open swimming space, stable water parameters (salinity ~1.020–1.025, temp ~72–79°F, pH ~8.1–8.4), and a secure lid since many jawfish are prone to jumping. Diet should consist of meaty foods such as mysis shrimp, brine shrimp, copepods, and high-quality pellets, and with proper care this fish makes a standout addition to the aquarium.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.